Page Contents:
The Use of 2,4,5-T in Victoria (various)
Forest Commission Victoria Decisions (1974-79)
Pesticide Review Committee Minutes (1969-1977)
The Herbicide 2,4,5-T and its use in Forestry
Tree Fern Removal - Strzelecki Ranges 1994-98.
K.J. Simpfendorfer.
(This excellent article was first published in 1967 on a paper presented to the 39th ANZAAS Congress, Melbourne, January, 1967 and later published in Forestry Technical Papers No. 19 - Victoria Forests Commission).
A. HISTORY.
The history of exotic forest and land use has passed through several phases during the past hundred or so years. Although Victoria was naturally well endowed with native forests, the introduction of exotic trees seems to have occurred within months of the first settlement. Early introductions were probably for reasons of sentiment, as abundant supplies of timber were available from the native forests, even though the timber characteristics of the local hardwoods were very different from the familiar softwoods of the northern hemisphere.
It was during the 1840's that the first plantings for protection appear to have been made, but it was not until the introduction of Pinus radiata D.Don by Baron von Mueller in 1859 that windbreak planting commenced in quantity. Pinus radiata was a very successful introduction from the first and during the 1860's and 1870's was planted extensively as shelterbelts in a wide range of climatic zones. Concurrently with this expansion a wider interest in other species developed, leading to the establishment of the Macedon Forest Nursery in 1872.
With the decline of the gold boom of the 1850's and the need to find employment for ex-miners, land settlement schemes expanded rapidly in the 1870's and 1880's. Large areas of highly productive forest throughout the medium to high rainfall areas of the State were released for settlement and it was during this period that the prime forest of the Otways and Gippsland regions was alienated; reducing the State's reserves of high quality forests to about half their former extent. Much of this country is now highly productive agricultural land but on large areas settlement has either failed or is a very doubtful economic proposition for both the owner and the community.
Alienation of forest areas was a very live issue and while only small, little more than token areas were reserved, it did plant the ideas of reforestation. For the first time it was realized that the "vast and inexhaustible" reserves were neither vast nor inexhaustible and a start was made by the State with the planting of a small area of P.radiata near the Macedon nursery in 1880. During the period 1880-1910 further projects were commenced at Mt. Macedon, Creswick and the You Yangs, representing high, medium and low rainfall areas. This period may be regarded as an experimental era; while the actual areas planted were small, techniques were evolved and over a hundred hardwood and softwood species of commercial value were tried in plantation formation.
Throughout these trials P.radiata was generally the most successful species. Its extensive use as a shelterbelt tree since about 1860 further confirmed its adaptability and suitability to a wide range of sites and was largely responsible for the fallacious belief that "it would grow anywhere." While it is a very versatile tree as regards site, it has definite limitations, particularly under conditions of excess or limited drainage, but the "grow anywhere" belief was carried to extremes and led to some rather unfortunate results.
B. PRE-WAR II PERIOD.
Planting of exotic forests began to expand in 1910, partly to provide for future timber requirements and partly to utilize land not suitable for agriculture. This may be regarded as the first conscious attempt at land use. Operations continued at varying levels and, may be divided into three main eras, witha few minor ones:-
1. Coastal sands 1910 - 1935.
2. Foothill Country 1925 - 1938.
3. Marginal farmlands 1930 - 1939.
4. Miscellaneous.
1. Coastal Sands.
While much of the better quality forest in Victoria had been alienated by 1900-1910, the poor quality brown stringybark (Eucalyptus baxteri (Benth Maid. and Blak.)) forests on the sandy soils along the coast were of very limited forest value, and, judging by the absence of selection pressures, of little use for agriculture.
Following the acceptance of the "pines-will-grow-anywhere" belief, it was considered desirable in the interests of better land use, to convert these areas to softwood plantations; but however commendable the motive may have been, the results led to a most unfortunate phase of reforestation in Victoria.
Operations commenced at Frankston in 1910, French Island 1911, Wilson's Promontory about 1913, Port Campbell 1919, Anglesea 1923, and Mt. Difficult 1925. (Mt. Difficult, although not in a coastal area, is of the same soil type as the others and originates from the same era). Some 12,000 acres were cleared and planted but planting generally failed. Satisfactory areas of growth were very limited and scattered, so that consolidation was not practical. Planting generally ceased in the 1920's with minor work up to 1935, and except for a few hundred acres at Port Campbell, these plantations have now been utilized and the land disposed of to other interests. It is regrettable that despite the costly example of these failures, pressures still occur from time to time for major planting to be undertaken on similar soils in other parts of the State.
Numerous trials and investigations have been undertaken over the years in an
effort to determine the cause of failure. There is no one explantation to suit
all cases, but the commonest cause is either excess or inadequate drainage.
The older sands, particularly those on a gently undulating uplifted plain are
almost invariably unsatisfactory but younger soils developed on the slopes of
dissection lines and from recent geological activity are usually suitable. On
the older sands where inadequate drainage is the main cause of failure, it is
possible that deep ploughing or ripping (3 to 4 feet depth) with mole drainage
could be satisfactory. Application of phosphatic fertilisers has given good
responses on some types but the indicated frequency and rate of application
made the economics doubtful. Moreover, the response areas comprise only a minor
proportion of the total area and are usually dispersed through much larger areas
of unsuitable country.
Planting on coastal country has not ceased altogether; in fact, one of the largest current projects is on the sandy country of the south-west. Careful survey is necessary to define planting areas and it is only on soils developed on the Gambier Embayment and Recent period activity in the Dartmoor locality that any substantial areas of suitable country have so far been located. Soils derived on Pleistocene or older sands are usually unsatisfactory. In the south-west there is more than a million acres of sand country, but in the light of present knowledge only a small proportion of it is suitable for softwood reforestation.
2. Foothill Country.
By the mid 1920's it had become apparentt that the coastal sands were not suitable for P.radiata and while other species and techniques were tried during the following few years, activities were generally transferred to the foothill country of the central and north-eastern highlands.
Native forests around Ballarat suffered severely as a result of the demand for mining timbers and despite silvicultural treatment, recovery in some cases was slow. Conversion of some of these poorer areas to softwood commenced on a small scale in 1916, but most of it was undertaken in the 1925-1935 period. Generally the results have not been very successful, and no further extension of this class of planting is proposed for the present. However, investigations are in progress as it is estimated that some 30,000 acres of low quality native forest is available in the region and with its close proximity to the Ballarat, Geelong, and Melbourne markets it represents a potentially valuable area.
In the north-east of the State there is a very large area of forested country carrying faulty and defective timber of little or no commercial value. In 1927 a start was made at Bright and Myrtleford to convert some of this class of softwoods with a further project commencing at Beechworth in 1931. Within a planting unit there was no selection of site, so that some poor areas have been planted. Some were also too steep for subsequent operations.
The total area of foothill type forest carrying non-merchantable timber in the north-eastern highlands totals some millions of acres. Much of it is too poor and/or too steep for reforestation purposes but even excluding these areas the remainder still represents the largest potential for reforestation in the State. Up to 1939 only about 20,000 acres had been converted to softwood.
3. Abandoned Farmland.
The high quality forests of the Otways region were opened for settlement in the late 1870's but within about 50 years the forest authorities were resuming areas abandoned, or acquiring them at nominal prices. The opening up of the high country in the Otways and Strzeleckis from 1975 onwards for settlement represents one of the most unfortunate cases of wrong land use in the history of the State. Besides the loss of timber, the financial loss to the community and the wastage of human effort over two generations cannot be calculated, and only serves to emphasize once again that settlement of forested land needs to be carefully investigated.
Some of the land naturally reverted to forest but some 7,000 acres near Beech Forest have been replanted. A variety of softwoods was planted in the 1930-1938 period and now forms one of the most productive stands in the State. Several thousands of acres of bracken- and scrub-covered private property still exist and are potentially available. It is probably that with the exception of some very good farmland along the main Otways ridge most of the region will eventually revert to forest.
A similar position exists in the higher country of the Strzelecki Ranges where there is an estimated 200,000 acres of land which in retrospect it is apparent should not have been cleared. Much of this has been acquired by public and private interests, generally at token prices, and is or will be replanted with both softwoods and native hardwoods. Over the next 20 to 25 years this region will be one of the main centres of reforestation in the State.
4. Miscellaneous.
While the three previous examples of land use and exotic trees represented the major part of the acreage planted up to World War II there are several other smaller and possibly more interesting cases of land use.
(a) Auriferous Areas. An aftermath of the gold mining era in Ballarat, Creswick and Castlemaine was the denuded and unproductive areas of worked-out diggings. Partly to put the land to better use and partly to hide an unpleasant sight, planting of such areas commenced in 1888 at Creswick and at Ballarat and Castlemaine in 1919. Under natural conditions the auriferous soils are too poor for satisfactory tree growth but when disturbed by mining operations a big improvement is often obtained. This is largely a reflection of internal soil drainage and root penetration; under natural conditions the soils are compacted with a relatively impervious B horizon underneath a shallow A horizon, but mining operations results in several feet of "loose" soils being created. Responses like this suggest that deep cultivation to 3 or 4 feet may give a big improvement in site where low quality is due to compacted soils and not inadequate soils depth.
When most of the mined land had been planted, activities extended to the surrounding low quality native forest. Generally these did not prove to be very satisfactory, so that further extension has been confined to the more favourable localities.
(b) Dredged gravels. During the 1890's and early 1900's gold dredging extended into the Ovens Valley and its tributaries. At the peak of operations more than 40 dredges operated in the valley destroying large acres of alluvial flats and leaving a churned up mass of course gravels.
An experimental planting of 80 acres of P.radiata at Bright in 1916 on dredge trailings was very successful, so that over the next ten years several hundred acres were planted. These areas are some of the best in the Bright group of plantations.
Areas dredged more recently are not so satisfactory. With improved techniques and processing, soils have been disturbed to much greater depths and too high a proportion of the finer particles have been washed out. On such areas tree growth has not been satisfactory and many are now being converted to pasture of a kind.
(c) Fire-killed areas. Following a succession of fires some thousands of acres of high quality hardwood forest in the upper Yarra-Latrobe-Acheron watersheds had over a period of years been reduced to open bracken fern. Planting of these with softwoods commenced at Narbethong in 1934 and Noojee 1935. Both areas were burnt in the 1939 fires and have been replanted. There are still many thousands of acres of similar country in small blocks throughout the above catchment areas, but because of their scattered nature and now that suitable techniques for large scale planting of native eucalypts have been evolved over the last 30 years they are being replanted with species native to the locality.
(d) Noxious Weed Control. During the 1920's some hundreds of acres in the Ovens Valley infested with St.Johns Wort were planted with softwoods. The stands gave good control on the planted area but of course had no effect on other areas.
C. POST-WAR PERIOD
Prior to World War II most of the planting in the State was undertaken by the Forests Commission with limited plantings by some other Government and semi-Government organisations. Private planting had been virtually confined to the activities of some afforestation companies in the extreme south-west of the State and to woodlot planting on farms. At the close of World War II, it was estimated that the total area of softwoods in Victoria was approximately 57,000 acres.
Immediately after the war planting was resumed by the Forests Commission, but sever reduction in Loan funds in 1951 meant that planting during the 1950's was virtually nil and was not resumed on a worth-while scale until 1961. Contrasted with this, private reforestation has increased markedly, so that at present its total area and annual planting rate exceeds that of the Forests Commission. Comparitive total area figures (as at 31/12/1966) are 89,700 acres for private plantations and 72,100 acres for Forests Commission areas.
The big increase in private plantings has been due mainly to activities of the A.P.M. Forests Pty Ltd., which since 1951 has been planting approximately 3,000 - 4,000 acres each year in Central Gippsland. Their present area (as at 31/12/66) is 49,200 acres. Other large private owners are Sapfor Ltd, 15,010 acres and Softwood Holdings Ltd. 13,150 acres.
The expansion of planting in the post-war years has seen the emergence of slightly different approaches by the government and private sectors as to what constitutes the lower limit of land suitable for planting. Government activity can potentially spread over most of the State, so giving a wide range of sites from which to choose whereas a private organisation is more concerned with forest resources close to its conversion or manufacturing centre. Consequently its choice of sites is more limited and it may be more economical to plant a poorer site close to its facilities than a better site one or two hundred miles away. This has led to private organisations planting some thousands of acres of sand country which the Government would be reluctant to consider at present.
Each locality needs to be considered seperately in the light of the organisation involved, its management objectives and economic policies. The interaction of these may be quite complex, so at this stage of development of the State it is not possible to indicate conclusively what would constitutute the lower limit of land use. . .
post - war private and public planting has been undertaken on similar classes of country. Whereas pre-war I the selection of planting sites in the main tended to be based on utilizing a certain class of country, for example, coastal sands or foothill country, and then to select suitable sites within this class; the approach in post-war years has been to select suitable sites without being unduly concerned with the particular class of country involved. The effect of this has been that the range of country planted has broadened considerably and now comprises the suitable sites of almost all the classes previously tried.
Without distinguishing between public and private operations, the main classes currently being used are:-
1. Younger coastal sands.
2. Unproductive native forest.
3. Abandoned and marginal farmlands.
1. Younger Coastal Sands.
Reference to activities on this type has already been made. In the immediate post-war years large areas were planted in the south-west between Portland and the State border and the main ares have now been planted or committed. Until techniques giving rise to satisfactory growth are evolved it is unlikely that any greater major use than that attained or planned could be anticipated. As far as the eastern Victorian sands are concerned preliminary surveys show that they are similar to the south-western and southern types but the much greater frequency of seasons of summer rainfall with its consequent higher humidity and risk of fungal infections (mainly Diploidea) emphasizes the need for caution before embarking on any major project.
2. Unproductive Foothill Forest.
This class is bsically the same as the class "Foothill Country" referred to earlier but the above term is used to distinguish the proposed planting areas from the productive and potentially productive foothill forest of medium to high quality. It comprises the lower quality areas and while theoretically these could in time be improved to form useful native forest the cost of rehabilitation, coupled with the relatively slow growth rate and long rotation, make them an uneconomic proposition.
The area available and suitable for softwoods has not been completely assessed. In general terms it is known to be some hundreds of thousands of acres throughout the medium to high rainfall areas of the State and will represent the main area of activity in the future.
3. Abandoned and Marginal Farmland.
Next to the "Unproductive Foothill Forest" class this represents the largest area available for reforestation. It is usually land which under natural conditions carried good quality forest and so was assumed to be good agricultural land but on which far a variety of reasons farming has not been very successful. Much of it is still only partly cleared.
The largest area is in the higher parts of the Strzelecki ranges. A gross area of 200,000 acres could be available and up to date approximately 130,000 acres have either reverted to the Crown or been purchased by public and private forest interests. Most of the land purchased has been acquired since World War II, initially at prices of $1-3 per acre but as the poorer farms have been acquired prices have risen to $10 to $15 per acre.
A similar but smaller region exists in the Otways. Land resumption commenced in the 1920's and some 30,000 acres have been acquired. Further extension is limited as it appears that only some 12,000 - 15,000 acres could be regarded as purchase possibilities.
Land resumptions have not been confined to these two areas but have been in progreess in most areas of the State where public or private reforestation has been undertaken. Surveys and reconnaissances have shown that large areas could still be acquired, so that the total area of marginal farmland potentially available is large, possibly as much as 100,000 acres. Most of it is in regions where the growing season is short, topography is too steep, or the soils are poor and impoverished. . .
Public reforestation since 1961 has been increased to an annual planting of 6,000 acres of softwood. The Commonwealth Government has announced a program of financial assistance to the States aimed at planting 65,000 acres of softwood each year, of which Victoria's share will be 15,000 acres. The present intention is that the project be continued for 40 years, i.e. approximately one rotation for P.radiata, so that 600,000 acres of land will be required.
In arriving at these figures it has been assumed that private interests throughout the Commonwealth will plant an average of 10,000 acres per year, even though annual plantings may fluctuate from year to year. It is probable that 6,000 acres of this total will be planted in Victoria, representing a total area of 240,000 acres over 40 years.
The proposed public and private program over the next 40 years, together with the 154,000 acres at present established, would give a total acreage of about one million acres of softwoods early next century. This is a large increase over the present area but it is necessary to keep it in perspective in relation to other land uses. It represents less than 2 percent of the total area and less than 6 percent of the total timber area in the State so that the overall impact on either will not be great. Some of the land to be planted will be alientated land but although the figures quoted earlier on the estimated area of abandoned and marginal land may appear to be large, they represent less than 1 percent of the total area of agricultural land in the State, while their contribution to production and revenue of the community as a whole is negligible.
E. CONCLUSION.
Although pressures for planting land may increase in the future, softwood reforestation will by and large fill a gap in the present general pattern of land use. On the agricultural side, most of the productive land receives less than the optimum rainfall for softwoods, has an unsuitable soil type, or is in well improved farms where the initial purchase price and compound interest for 40 years would make reforestation uneconomic. From the forestry aspect productive or potentially productive stands on areas which can be economically rehabilitated will be retained as native forest. In between these two limits there is a large class comprising marginal farms, isolated blocks of timbered private property, and unproductive and uneconomic native forest. It is in this class of country that public and private softwood reforestation will generally be undertaken. It will lead to a much more rational land use and will eventually bring into highly profitable production about a million acres of land most of which is at present making a negligible contribution to the community.
The Forests (Wood Pulp Agreement) Act 1966. by L.B. Williams. Forestry Technical Papers.
This paper helps explains that after the 1939 bushfires there was a shortage of timber anticipated for the Maryvale Pulp Mill. 1936 Legislation guaranteed A.P.M. a supply of timber that would feed their newly made mill. The bushfires upset this supply arrangement and plans were drawn up some years later to plant forests on Crown Land and private land that would be used exclusively for the pulp mill. This led to the 1961 Wood Pulp Agreement Act and numerous variations since.
p36 "To help overcome this deficiency the 1966 Act lays down the procedure to be adopted for the leasing of Commission land to the company for the growing of trees for pulpwood. This should assist the company to develop an additional reserve of high grade pulpwood - particularly of Mt. Ash.
At the present time the Company leases from the Commission about 8700 acres of land in the eastern Strzelecki Ranges. terms of this lease require the company to establish trees in the plantable area contained therein over a period of 16 years. Since 1961 more than 200 acres have actually been established. It is anticipated that a further area of about 12000 acres will be made available in the Middle Creek and East Morwell river basins. This area abuts the current lease area and would in effect be an extension thereof..."
ADVANCES IN CONTROL OF WOODY WEEDS IN RADIATA PINE PLANTATIONS IN VICTORIA
D.W. Flinn and G.Minko 1980? Forests Commission Victoria
“INTRODUCTION
Sites converted from native eucalypt forests to plantations of radiata pine in Victoria are generally recolonised soon after planting by a wide range of herbaceous and woody plants. Of these, eucalypts and silver wattle exhibit rapid early growth rates and compete with radiata pine. At the highest density of woody weeds studies by Jack (1970), merchantable volume of a 51 year old stand of radiata pine had been depressed by 80%. Manual, mechanical and chemical methods have been used to control woody weeds in young plantations of radiata pine in Victoria. The method adopted has been largely based on available technology and economic and environmental factors. . .
PAST PRACTICES FOR WOODY WEED CONTROL
Until the early 1960’s, native forest was felled and broadcast burnt prior to planting of radiata pine. Repeated manual methods were needed to control woody weeds. Heaping and windrow burning then replaced broadcast burning allowing many sites to be ploughed before planting. This reduces the eucalypt component; temporarily controls many herbaceous weeds and provides a favourable micro-environment for establishing radiata pine seedlings.
In 1968 aerial application of 2,4,5-T approximately three years after planting was introduced to control silver wattle, followed by basal bark spraying or stem injection of the eucalypts with mixtures of 2,4,5-T and picloram (Flinn and Hopmans 1977). Since this control of eucalypts is labour-intensive, ploughing significantly reduced the total cost of woody weed control. Aerial application of 2,4,5-T has not been made by the FCV since 1977, and there has been increasing pressure on all 2,4,5-T based herbicides including those commonly used for stem injection. Since new plantations of radiata pine are being established by the FCV at about 2000 ha per year on sites cleared of native forest, and as the cost of hand slashing woody weeds can be prohibitive, there was an urgent need to find alternatives to 2,4,5-T . . .”
EVALUATION OF HERBICIDES FOR STEM INJECTION OF WOODY WEEDS IN YOUNG RADIATA PINE PLANTATIONS. G. Minko and D.W.Flinn 1980
“Until recently, the Forests Commission Victoria has used a combination of aerial spraying with 2,4,5-T, followed by stem injection with Tordon 105 (Picloram + 2,4,5-T) to control those woody weeds early in the rotation (Flinn and Hopmans 1977). Alternative herbicides have been investigated for broadscale application following restrictions placed upon the use of 2,4,5-T in Victoria and elsewhere in the late 1970’s. (Flinn and Minko 1980, 1981, Flinn et al. 1980). . .
“ PESTICIDES IN THE FOREST ENVIRONMENT. USE OF 2,4,5-T FOR CONTROL OF WOODY WEEDS IN PINUS RADIATA PLANTATIONS IN VICTORIA. By D.W. Flinn and P. Hopmans.
“. . . The application method is dictated by the density and size of the weeds. Basal bark spraying and stem injection are used where weed density is low and an aerial application at 1.1kg/ha 2,4,5-T where weeds are denser . . . Studies have demonstrated that 2,4,5-T is degraded in the forest environment, principally by photodecomposition and soil microorganisms, to harmless end products. Less is known about the breakdown of TCDD. . . Dense scrub growth often develops following conversion of native eucalypt forests to Pinus Radiata D Don plantations in Victoria. This scrub, especially eucalypts and wattles (eg Acacia dealbata Link.) competes strongly with the young pines and substantially reduces yields (Jack 1970) . . . Application is at the rate of 1.1 kg 2,4,5-T in 50 l dieseline/ha during winter . . . Since 1968 over 16,000 ha have been successfully treated . . . Although the degradation of TCDD has not been studied in detail and hence breakdown pathways and products have not been characterized . . . Recent studies indicate that TCDD is subject to photodecomposition (and presumably microbiological breakdown) and is very immobile in soils. Rates of decomposition are slow compared with 2,4,5-T. Animals excrete around 30% of TCDD immediately and high percentage of the balance within a few days. . .”
BROADSCALE FOREST USE OF HERBICIDES IN VICTORIA 13/6/03
BY J.B.JACK. FORESTS COMMISSION - VICTORIA
Paper presented to section K, A.N.Z.A.A.S. 40th Congress - Christchurch, 24-31 January, 1968.
TECHNICAL FACTORS
p2 “Screening tests for suitable chemicals have been carried out since the early 1950’s. The chemical 2,4,5-T (2,4,5-Trichlorphenoxyacetic acid) gave excellent control of Acacia dealbata Link. as well as showing early promise in the control of eucalypt coppice. Later trials have confirmed the suitability of 2,4,5-T for certain situations and its limited application for growth control in plantations. Tordon (4-amino-3,5,6 trichloropicolinic acid) now appears as the most promising chemical in the woody growth control field.
p 3 APPLICATION TECHNIQUE
High volume foliar applications have generally been impractical in Victorian plantations because spraying equipment cannot move through the rows, even though technically they have proved equal if not superior to misting or injection techniques. Foliar applications by back-pack misters have given good control in small trials but in larger scale use the results have been poor . . .
ENVIRONMENT
Weather conditions can affect the results of spray operations. Aerial spraying of forest stands in Victoria with 2,4,5-T ester in oil or water has seldom resulted in more than 50% of the spray output being recorded on the spray area in droplets larger than 100 microns. When wind speeds of >5 m.p.h were recorded <30% of the spray reached the target. In contract to this 90% of aerially applied 2,4,5-T invert reached the target in winds of 8 to 11 m.p.h. The frequency of adiabatic winds in forest areas and the difficulty of flying close to the canopy make forest aerial spraying more hazardous than the usual agricultural operation both from the point of view of the pilot and the successful application of the herbicide to the target area.”
12/2/74: File Number 73/111. Chemical (Tordon herbicide). Spillage at Sherbrooke Falls. Commission Decision 74/6/16. Arrangements to be made for removal of unsafe dead trees. Advisory Committe to be informed.
11/3/74: File Number 74/414. Purchase of 2,4,5-T for Aerial Spraying Operations. Commission Decision 74/11/10. Approved recommendations submitted by Chief, Division of Forest Operations on 18/3/74.
12/3/74: File Number 73/2452. Zinc Spraying 1973/74. Commission Decision 74/10/20. Tender of A.G. Airwork Pty Ltd viz $2.10 per acre accepted.
6/6/74: File Number 74/200. Aerial Spraying of Wattle Areas 1974. Commission Decision 74/21/16. Recommend to Minister purchase ex Nufarm Chemicals Pty Ltd of 770 gallons of 2,4,5-T Technical Butyl Ester at $1.985 per lb (total cost $20,174) in accordance with company's quotation dated 23/5/74. MINISTERIAL APPROVAL 6/6/74.
20/11/74: File Number 74/1644. Aerial Dessicant Spray Operations 1974/75. Commission Decision 74/45/11. Quotation of Nufarm Chemicals Pty Ltd viz $1,623.60 accepted for supply of 60 gallons of technical buytl ester 2,4,5-T on accordance with company's letter dated 29/10/74.
?: File Number 74/2407. Zinc Sulphate - Aerial Spraying Rennick FD. Commission Decision 75/9/21. Tender of Western Aerial Crop Spraying and Spreading Pty Ltd viz $2.90 per ha accepted for spraying to specification with zinc sulphate 600 ha +- 20%.
13/3/75: File Number 74/414. Purchase of 2,4,5-T for aerial spraying operations - 1974. Commission Decision 75/10/14. Recommend to Minister purchase ex Nufarm Chemicals Pty Ltd of 2500 litres of 2,4,5-T to specifications at $2.10 per lb ($4.63 per kg) at a total cost of $15,047.50 with an option of purchase up to 4000 litres at same unit rate. MINISTERIAL APPROVAL 13/3/75.
26/3/76: File Number 76/412. Zinc Spraying 1976 Rennick State Forest. Commission Decision 76/13/5. Approved recommendation submitted by Chief Silvicultural Office on 26/3/76.
10/5/76: File Number: 74/1644: Aerial Desiccant Spray Operations 1974/75. Commission Decision 79/19/34. Approved recommendation submitted by Chief Division of forest operation on 10/5/76.
12/8/76: File No's 76/1524. Purchase of Herbicides Yarram Forest District. Commission Decision 76/32/23. Recommend to Acting Minister purchase ex Ciba-Geigy Aust Ltd of 156 x 20 Litres Weedazol TL Plus at $1.90 per litre (less 6%), 163 x 20 L Gesaprim 500 FW at $3.22 per litre as per State Tender Board contract and 65 litres of Plus 50 Surfactant at $1.04 per litre. Total Cost $16,137.12.
3/5/77: File Number 74/414. Purchase of 2,4,5-T for Aerial Spraying Operations 1974. Commission Decision 77/18/15. Recommend to Minister purchase ex Lane Ltd of 2440 litres of 2,4,5-T butyl ester (80% w/v) at $6.25 per litre as per company's quotation dated 2/5/77 - Total cost 15,250.
7/6/77: File Number 77/457. Aerial Spraying Wattle Control 1977 - Commission Decision 77/23/4. Tenders accepted for wattle spraying in accordance with schedule recommended by Silvicultural Officer B.T. Evans on 1/6/77.
19/7/77: File Number 77/457. Aerial Spraying - Wattle Control 1977. Commission Decision 77/29/11. Quotation dated 21/6/77 from Super Spread Aviation (Australia Ltd) viz $175 per hour working time and $95 per hour ferry time accepted for spraying to specification for wattle control on 300 ha +- of pine plantation in Myrtleford Forest District.
5/7/77: File No's 76/1524. Purchase of Herbicides Yarram Forest District. Commission Decision 77/27/8. Recommend to Acting Minister purchase ex Ciba-Geigy Aust Ltd of 201 x 20L Weedazol TL Plus at $1.50 per litre, 320 x 20 L Gesaprim Flowable at $3.40 per litre and 3 x 20 litres plus at $1.27 litre as per Company's quotation dated 17/6/77. Total cost $27,866.20
3/8/77: File Number 76/143. Plantation Establishment and Tending Yarram. Commission Decision 77/31/18. Tender of Skyfarmers Pty Ltd Vic $123.50 per hour flying time and $93.50 per hour ferry time for Cessna Agwagon accepted for spraying 920ha +- 20% of softwood plantation for grass control in Yarram Forest District.
17/1/78: File Number 75/2534. Plantation Establishment and Tending - Heywood F.D. Commission Decision 78/3/15: Approved purchase of ex Phosphate Co-op Australia Ltd of 120 tonnes granulated superphosphate in woven bags at a total cost of $7231.20.
17/1/78: File No: 77/1524. Aerial Fertilsing with Super Phosphate. Commission Decision 78/7/34: Approved recommendations submitted by Silvicultural Officer on 13/278.
31/1/78: File Number 77/1524. Aerial Fertilising with super phosphate. Commission Decision 78/5/8. (a) Recommend to Minister purchase ex The Phosphate Co-op of Australia Ltd of 933 tonnes of granulated super phospahte at $50 nett per tonne and 152 tonnes of granulated super potash 5 & l at $63.71 net per tonne. Total cost $56,333.91. (b) Invite quotations from known aerial contractors for transport, storage and aerial application of fertiliser on 1391 +- of plantation.
17/5/78: File Number 77/2456. Replanting Pine Plantations burnt at Creswick during February 1977 - Creswick FD. Commission Decision 78/19/13. Approved purchase ex Ciba-Geigy Australia Ltd of 480 litres of "Roundup" at $14.90 per litre.
?/5/78: File Number 74/414. Purchase of 2,4,5-T for Aerial Spraying Operation 1974. Commission Decision 78/20/12. Recommend to Minister purcahse ex Nufarm Chemicals Pty Ltd of 1800 litres 2,4,5-T as butylester (80% w/v 2,4,5-T) at $6.72 per litre in 20 litre drums. Total cost $11,196.
23/5/78: File Number 78/491. Aerial Spraying - Wattle Control 1978. Commission Decision 78/20/11. Approved recommendation submitted by Silvicultural Office on 10/5/78 as amended and initiated by the Chief Division of Forest Operations.
26/7/78: File No's 76/1524-76/143. Purchase of Herbicides Yarram District. Commission Decision 78/29/25. Approved purchase 26/7/78. (a) ex Nufarm Chemicals Pty Ltd of 87 x 20 litres of Amitrole T at $1.59 per litre as per State Tender Board contract and 2 x 20 litres surfactant at $1.24 per litre. (b) Ex Ciba-Geigy Australia Ltd of 152 x 20 litres of Flowable Gesaprim (Atrazine) at $2.45 per litre as per company's quotation of 6/7/78.
1/8/78: File No 75/550. Purchase of Hi-Ball and Chain for Machine Clearing. Commission Decision 78/30/10. Approved purchase. Ex Falkiner Chains Pty Ltd of four 28 metre lengths of 2 inch stud link chain, "U2" quality at a total cost of $5,840.00 and seven only Bolt Type Joining Shackles at a total cost of $120 each, in accordance with company's offers dates 11 July 1978 and 18 July 1978.
4/10/78: File No 75/2575. Plantation Establishment and Tending-Myrtleford FD. Commission Decision 78/39/11: Approved spraying for grass control on 150 hectares +- of softwood plantation in Myrtleford Forest District in accordance with programme detailed in letter dated 19/9/78 to Pesticide Review Committee.
25/1/89: File No's 77/1524-78/2141. Aerial Fertilising with Super Phosphate. Commission Decision 79/4/8: Recommend to Minister purchase of the PhosphateCo-operative Company of Australian Ltd of 1023 tonnes of granulated super phosphate at $51.40 net per tonne and 162 tonnes of granulated super potash 5 at $65.04 net per tonne - estimated total cost $63, 118.68.
28/2/79: File No: 77/1524. Aerial Fertilsing with Super Phosphate. Commission Decision 79/8/27: Recommend to Minister for spreading fertiliser to specifications on softwood plantations as follows: With Super Spread Aviation (Australia) Pty Ltd of 160 tonnes at $19.60 per tonne at Toolangi, 223 tonnes at $29 per tonne at Alexandra, 206 tonnes at $23.50 per tonne at Marysville, 162 tonnes at $26.90 per tonne at Mirboo and 202 tonnes at $27.05 per tonne at Erica and with Western Aerial of 207 tonnes at $17.19 per tonne at Daylesford and 25 tonnes at $19.50 per tonne at Ballarat.
7/3/79: File Number 75/2534. Plantation Establishment and Tending - Heywood F.D. Commission Decision 79/9/19: Approved purchase of ex Phosphate Co-op Australia Ltd of 100 tonnes superphosphate in woven bags at a total cost of $5883.
12/4/79: File No: 77/1524. Aerial Fertilsing with Super Phosphate. Commission Decision 79/14/15: Approved recommendations submitted by Chief Silvicultural Officer.
MINUTES OF THE TWENTY SECOND MEETING OF THE PESTICIDES REVIEW COMMITTEE 22/11/68.
31 Letter received from Forests Commission (maps enclosed) advising of spraying program at Brittania Creek, Fitzpatrick Road, Ada River, Dowey’s Spur and Learmouth Creek Road.
Decision 22.11.68. To notify Forests Commission that the Committee approved of the spray program and that there could be representatives of interested Departments on site during the spraying. Copy of Forests Commission letter to be circulated to members.
MINUTES OF THE TWENTY THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 7/2/69.
Forests Commission Aerial Spraying. Letter dated 23rd December received from Forests Commission requesting extension of area to be sprayed. Amalgamated Chemicals to supply ‘Dibrom’ as comparison to Malathion. Area to be sprayed 100 acres.
MINUTES OF THE THIRTY FOURTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 10/4/70.
Decision 10/4/70. To notify that the Committee has no objection to the conduct of the trials as indicated.
(5) Forests Commission, in co-operation with Dow Chemicals (Aust) Ltd; Woady Yallock Creek near Scarsdale.
Decision 10/4/70. To notify the Forests Commission that the Committee has no objection to the conduct of the trials as indicated, but that the Forests Commission should notify the Committee of results of the trial.
MINUTES OF THE THIRTY FIFTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 15/5/70.
52. Dangers of 2,4,5-T - A letter to the Secretary, Premiers Department, from the Consul-General of the USA, underlining the dangers of the weed killing chemical 2,4,5-T was forwarded to this committee. (Also mentioned in 36th and 37th meeting).
MINUTES OF THE FORTIETH MEETING OF THE PESTICIDES REVIEW COMMITTEE 6/11/70.
ITEM 3: (a) Letter received from Forests Commission, Victoria, dated 29th October, advising the proposed desication of scrub land preparatory to the rehabilitation of former forested land back to productive forest. The chemical to be used is 2,4,5-T.
MINUTES OF THE FORTY FIRST MEETING OF THE PESTICIDES REVIEW COMMITTEE 11/12/70.
31 Aerial Spraying by Forests Commission The Chairman advised the meeting that after discussion with Mr McKenzie he had rung Dr Moulds concerning the area to be sprayed. It was thought that it might be too close to the water take-off at Brittania Creek. Dr MacKenzie advised that he had visited the area to be sprayed. He said that it would not be necessary to take water samples as the water take off was more than a mile away. Mr Parsons queried whether the dioxin content of the Australian product of 2,4,5-T was as stong as overseas operations. It was advised that there are six companies manufacturing 2,4,5-T in Australia and it was decided to write to each to ascertain the strength used in their products.
31 Letter dates 30th Nov received from the Forests Commission advising of the proposed spraying of 15000 acres plus, for the control of phasmatid insects. The chemical compound to be used is Maldison.
MINUTES OF THE FORTY THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 5/3/71.
31 (b) Manufacturers of 2,4,5-T in Australia and the dioxin strength compared with overseas manufacture. Information was tabled which indicated that only two companies now make the compound in Australia. On the information supplied the dioxin content was shown to be less than 1ppm. and the committee felt that no further problem from this angle existing with the use of 2,4,5-T.
MINUTES OF THE FORTY FIFTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 14/5/71.
31 D (c) Forests Commission. Aerial spraying for control of weeds in young pine plantations. Letter received 13th May.
MINUTES OF THE FORTY SIXTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 18/6/71.
(c) Forests Commission Aerial spraying for control of weeds in young pine plantations. Letter received 13th May.
Decision 14.5.71. To advise the Forests Commission that the submission will be considered at the next meeting. A further letter dated 3rd June, concerning an area near Gellibrand, was received. This was added to the area already notified. Mr O’Brien advised that the Agriculture Department laboratories would be doing some collaboration analytical work on the scheme. Mr Dunk advised that the State Rivers and Water Supply Commission would prefer some form of control on the Tarra Valley area as the Yarram Water Supply comes from this area. 18.6.71
(a) To advise the Forests Commission that the Committee has no objection to the conduct of the spraying operation with the exception of the Tarra Valley from which the Yarram town water supply is drawn.
(b) The Committee would need to be convinced that spraying the Tarra Valley would be safe. Evidence of this point should be available from analytical data in other areas.
(c) To point out that because the compound concerned has been given adverse publicity recently more than usual attention should be taken to ensure that spray drift does not contaminate any waterways or storages.
(d) To suggest to the Commission that the applicator must have a permit from the Agriculture Department to use hormone sprays from the air.
(d) APM Forests Pty Ltd Letter received from APM dated 11th June outlining a spraying program similar to that proposed by the Forests Commission and also using 2,4,5-T. During discussions it was agreed that no catchment area or water supply would be affected.
Decision 18.6.71 (a) To advise APM that the Committee has no objection to the spraying operation as outlined. (b) To bring to the notice of APM that the applicator will require a permit from the Agriculture Department to use hormone spray from the air. (c) To point out that because this compound has been given adverse publicity recently, more than usual attention should be taken to ensure that spray drift does not contaminate any waterways or storage.
MINUTES OF THE FIFTIETH MEETING OF THE PESTICIDES REVIEW COMMITTEE 15/10/71.
Letter dated 13th October received from Forests Commission advising the proposed desiccation of scrubland preparntory to the rehabilitation of former forested land back to productive forest. The chemical to be used is 2,4,5-T. Decision 15.10.71
(1) To advise the commission that the committee has no objection to the spraying of the areas designated.
(2) To request that on future occasions directions in the contractor not to spray adjacent to streams for at least one chain, be included in the specifications to the contract.
(3) To request that water samples be taken before and after spraying and then after the first rain for analysis by the Department of Agriculture Laboratories.
(4) To ask if the commission has obtained data from previous operations and if so the committee would be pleased to have a look at the results.
MINUTES OF THE FIFTY SECOND MEETING OF THE PESTICIDES REVIEW COMMITTEE 17/12/72.
31 (c) Forests Commission - Letter dated 6th December received from Forests Commission advising that the Commission intended spraying certain areas of forest against the stick insect phasmatid.
MINUTES OF THE FIFTY THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 18/2/72.
Item 31 (c) Forests Commission - Reports dated 17/12/71 and 7/1/72 received on results of spraying programs carried out during the 1971 spraying season.
Decision - 18.2.72 To thank the Forests Commission for the reports on testing programs.
MINUTES OF THE FIFTY EIGHTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 1/9/72.
31 (c) Forest Commission Spraying Programme Letter dated 12th July received from Forest Commission advising the intention to carry out aerial spraying of various plantations of approximately 8000 acres located on enclosed schedule.
Decision: 21/7/72: (a) If the Committee has not already received a report from the Forests Commission about the efficiency of foam barriers, one should be asked for.
MINUTES OF THE EIGHTY NINTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 24/11/72.
No 31 (c) APM Latter dated 22 Sep received from APM concerning Dioxin produced by burning 2,4,5-T and including an article by Jane Cameron, University of British Columbia.
MINUTES OF THE NINETIETH MEETING OF THE PESTICIDES REVIEW COMMITTEE 24/11/72.
Letter dated 13th Nov, received from Forests Commission Victoria advising of the Commission’s proposed control measures against the plague proportions of the phasmatid Didymuria violesceus in areas of the Upper Yarra and Neerim Forest District No 31
(c) APM Letter dated 22 Sep received from APM concerning Dioxin produced by burning 2,4,5-T and including an article by Jane Cameron, University of British Columbia.
MINUTES OF THE NINETY FIRST MEETING OF THE PESTICIDES REVIEW COMMITTEE 16/2/73.
No 31 (a) Letter from Forests Commission dated 13 Dec received advising of spraying for control of phasmatids. The area to be sprayed is adjacent to the water catchment for the Warburton Water Supply. Letter received from MMBW dated 13th Dec confirming information provided by Forests Commission.
No 31 (c) APM Latter dated 22 Sep received from APM concerning Dioxin produced by burning 2,4,5-T and including an article by Jane Cameron, University of British Columbia.
MINUTES OF THE NINETY SECOND MEETING OF THE PESTICIDES REVIEW COMMITTEE 23/3/73.
31 (a) Letter of 16th March 73, received from the Forests Commission advising that it was proposed to spray a defoliant on scrub and blackberries at Turtons Creek, Mirboo Forest District so that the area of approximately 100 acres could be reforested.
31 (c) APM Forests Pty Ltd. Letter dated 22nd September received from APM concerning Dioxin produced by burning 2,4,5-T and including an article by Jane Cameron, Uni of British Columbia.
Decision: 20/10/72: To reply to APM Forests Pty Ltd advising that this committee is not the body to organise a symposium but that we would be very happy to see the results of such a gathering. Letter dated 13th Nov received from Mr Parsons commenting on paper by Jane Cameron student in Political Science.
Decision: 24/11/72. Mr Parsons to draft reply to APM on this matter. Secretary to provide Mr Parsons with a copy of the information involved. Letter Dated 29th Nov 72, and 11th Dec 72 received from Mr J Hall referring to the matters listed above.
MINUTES OF THE NINETY THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 12/4/73.
31 (c) APM Forests Pty ltd. Correspondence from Mr Hall APM wanting a symposium on 1080 - also letter from APM outlining maps where 1080 will be used in April May under direction of Lands Department.
MINUTES OF THE NINETY FOURTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 1/6/73.
31 (c) APM Forest Pty Ltd. (a) letter dated 14th May, received from APM concerning the use of Propazine and 2,4,5-T in various areas in Gippsland, and enclosing a map of the area.
(b) Forests Commission - Letter dated 18th May received from the Forests Commission enclosing maps of the areas in which it is proposed to aerial spray 9000 acres of pine plantation with 2,4,5-T. Decision: To approve of the proposal subject to:- (a) That sampling of the stream be carried out.
(b) That they advise any town authority where the water supply might be affected and also to advise the State Rivers and Water Supply Commission similarly.
MINUTES OF THE NINETY FIFTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 29/6/73.
31 (1) Letter dated 14th May received from APM concerning the use of Propazine and 2,4,5-T in various areas in Gippsland, and enclosing a map showing the area involved.
Decision: 1/6/73 To write and advise that more information is needed and that the committee would be prepared to meet them on a subcommittee basis if approval is required quickly. Advise that they have not advised what is intended to control - what amount of residue would be involved - the proximity to streams - how material will be applied and when.
Letter dated 15th June received from APM Forests Pty Ltd setting out the programme and specification to be used in this exercise.
MINUTES OF THE NINETY SIXTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 3/8/73.
31C Letter dated 25th July 73, received from APM advising of the proposed use of Simazine, Amitrol and 2,4,5-T on 220 acres of recently planted pines in the Flynn Creek Tree Farm at Rosedale.
MINUTES OF THE ONE HUNDRETH MEETING OF THE PESTICIDES REVIEW COMMITTEE 1/2/74.
Letter from Forests Commission 20th Nov to spray plague proportions of phasmatids in the Upper Yarra and Neerim forest districts (catchment areas).
MINUTES OF THE ONE HUNDRETH AND FIRST MEETING OF THE PESTICIDES REVIEW COMMITTEE 29/3/74.
16th Feb letter dated from APM - 1080 to be used in Gippsland Tree Farms - May 74.
MINUTES OF THE ONE HUNDRETH AND SECOND MEETING OF THE PESTICIDES REVIEW COMMITTEE 10/5/74.
(1) Letter dated 29th March received from APM Forests Pty Ltd advising the firms intension to spray 890 hectares of new ploughed ground with 80% w/w Simazine to prevent germination of grasses, cape weed and silver wattle. No Objection.
MINUTES OF THE ONE HUNDRETH AND THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 21/6/74.
(1) Letter dated 5th June, 1974 received from the Forests Commission advising that the Commission intends to aerial spray about 7,600 acres in various areas, with the defoliant 2,4,5-T. Mr McKimm advised that this was a tentative application and the spraying would depend on the receipt of an order for 1000 gallons of 2,4,5-T in July and must be done by the first week in August or not at all. He also said that further tests were being made concerning at what stage peaks of run-off into rivers from the forests occurs. Peaks occur at two different times, (a) at time of spraying (peaks last for 2-3 hours), (b) following rain in the sprayed area (peaks last for 8-10 hours). The Chairman said that the committee would be interested to see the results of the report to be made in conjunction with Agriculture Dept Laboratories.
Decision. To advise the Forests Commission that the committee has no objection to the spraying as set out.
MINUTES OF THE ONE HUNDRETH AND SEVENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 25/10/74.
(1) (a) Letter dated 24th September received from APM Forests Pty Ltd advising the intension to spray 275 hectares of farmland to control ragwort. (b) Forests Commission - letter received dated 17th October advising of proposed spraying of areas, 1. Upper Yarra district, 2. Nowa Nowa district.
MINUTES OF THE ONE HUNDRETH AND EIGHTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 29/11/74.
(1) Letter dated 7th November received from Forests Commission advising of proposed spraying of areas in Upper Yarra (New Turkey), Neerim (Carters Creek) and Erica (Western Tyers A,B & C) for control of plague proportions of phasmatids, during Jan 75. Total area to be sprayed 1070 hectares (2640 acres).
MINUTES OF THE ONE HUNDRETH AND NINTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 21/2/75.
Item 93 Use of 1080 for Vermin Control . . . Letter dated 3 January received from APM Forests Pty Ltd advising proposed use of 1080 for vermin control in various areas during May, 1975.
Decision 21.2.75 Mr Wharton to advise APM of the procedure necessary before controlling vermin with 1080 and that a permit must be obtained from Fisheries and Wildlife before undertaking such work.
(d) Tarra Valley National Park - Blackberry Spraying. Letter received from Mr O’Brien from the Department of National Parks requesting authority to spray blackberries along the Tarra River a portion of the area to be sprayed being a proclaimed water catchment area. It was stated that various restrictions would be enforced against spraying close to the stream and the cleaning of equipment used to spray. 2,4,5-T is the material to be used at a dilution of 1:600.
MINUTES OF THE ONE HUNDRETH AND TENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 11/4/75.
(1) APM FORESTS Pty Ltd (a) a letter dated 5th March 1975, received from APM advising that the company would be spraying specific areas with 2,4,5-T to control Blackberry and Brambles.
Decision 11.4.75 (i) To note receipt of the letter and the action taken (ii) To advise APM that the Committee regrets that the spraying was done prior to it receiving notification and would request that this be done in future.
(b) Letter dates 6th March received from Forests Commission, together with reports of studies carried out by the Commission on the safe control of Didymuria violescens.
MINUTES OF THE ONE HUNDRETH AND TWELFTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 27/6/75.
(A) (1) Letter dated 21st and 23rd April received from APM Forests Pty Ltd, advising plans for the use of 2,4,5-T to control noxious weeds in various areas of Budgeree, Bulga and Callignee. The Secretary advised Mr Pollock that approval could not be given until all information had been considered.
Mr Pollock has contacted the Secretary by telephone and said that in these instances the Coy. Had no option but to spray because a direction from the Vermin and Noxious Weeds Destruction Board had been received which required the spraying of blackberries and brambles by a certain time. Mr Jack said that this was a regular operation which was carried out each year and could conceivably be planned ahead and the committee notified.
Dr Christophers said what should happen now was for APM to make a general application for control of noxious weeds and having regard to the hazards which might be entailed, notify the committee when the project will be carried out.
Decision - To accept offer from Mr Jack that he would discuss the matter, along these lines, with Mr Hall of APM.
(b) Forests Commission. Letter dated 17th April received from the Forests Commission advising of proposed aerial spraying with 2,4,5-T during the winter.
Decision 9.5.75 - (1) To advise the Forests Commission that the Committee has no objection to the conduct of the spraying program as set out.
(2) That for future occasions when notifications are received from the Secretary, send a copy of correspondance, maps, etc., to Mr Bill for checking which will then eliminate the need for the full committee to look closely at the proposition.
(9B) (b) Use of 1080 for vermin control. Letter dated 29th April received from APM Forests Pty Ltd advising the proposed use of 1080 to control vermin under Health Department Permits held by the company. The areas to be treated are in the Parishes of Narrang, Windoo, Coolungoolun and Walla Wullock.
MINUTES OF THE ONE HUNDRETH AND THIRTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 25/7/75.
Item 1 APM Forests Pty Ltd Mr Jack reported that he had spoken to the manager of APM and Mr Pollock had not included in his notification, the precautions to be observed by spraying teams, although there has been a verbal acceptance of the suggestions made. Information was handed in at the meeting from APM Pty Ltd, inclcuding maps, appropriate areas, broad locations and the chemicals and rates of use.
Decision (1) That Mr Jack, Mr Pearce and Mr Bill form a sub-committee to consider the information provided. (2) To agree that the program as set out by APM be accepted. Mr Jack advised that in his opinion APM’s submission is a bit weak on the ‘precautions’ aspect. He suggests that the ‘specification for Aerial Spraying’ should be expanded to require:- 1) Notification, of neighbours and water users, of the intended operation. 2) Avoidance of spraying over running streams or dams. 3) That the chemical meets a specified tolerance and perhaps in the case of 2,4,5-T a purity level eg dioxin 0.5ppm.
In regard to the purity level of 2,4,5-T, Mr Jack said he had recommended a safe tolerance because dioxin could be present in this material especially in old stocks which could be unstable. It was advised that it was a general requirement for 2,4,5-T, produced in Australia, to be free from dioxin. Mr O’Brien offered to check this out with Mr Snelson in Canberra. Water Sampling, it was agreed, did very little good because it took only a short time to dissipate the chemical and in any case it was considered that the material prevented no great hazard at its registered strength . . .
Decision (a) To advise APM Forests and Lands that precautions should be observed as follows:- (1) Neighbours and water users should be notified of the intended operation. (2) Spraying over running streams and dams must be avoided. (b) That the Fisheries and Wildlife Branch check on the use of 1080 for the control of Black Faced Wallabies in pine plantations.
MINUTES OF THE ONE HUNDRETH AND FOURTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 19/9/75.
(1) APM Forests Pty Ltd, letter dated 6th August 1975, received, advising further areas in the Gippsland area proposed for spraying with 2,4,5-T. Letter dated 12th Sep, 1975 received in reply to ours of 4th September advising of the action taken by APM when spraying or baiting is to be carried out. Mr Bill advised members that the matter of aerial spraying and baiting by APM was discussed by the Water Commission and that the Commission was in favour of the Latrobe Valley Water and Sewerage Board and Waters Trust concerned, being notified when these were to take place Although it was considered that there was no great hazard involved it would be a good Public Relations exercise. It could be assumed that APM would be aware of the Public Relations angle.
MINUTES OF THE ONE HUNDRETH AND FIFTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 31/10/75.
(1) APM Forests Pty Ltd - Applications from approval to spray pine plantations have been received from APM from time to time and now a yearly program has been presented and agreed to by the Committee. The matter of notification of neighbours etc has been considered and Mr Bill has drafted a circular letter which could be used to warn those interested when spraying has to take place. It was pointed out that it would be better if the organization doing the spraying was to notify water authorities and diverters rather than have the water commission do this.
(3) Vermin and Noxious Weeds Destruction Board sprayingh of ragwort on Mt. Tassie area. Letter received from V&NWDB advising of the intention to spray 100 acres of ragwort in the Mt.Tassie area. Sparying to be carried out by aircraft.
MINUTES OF THE ONE HUNDRETH AND SIXTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 28/11/75.
(1) APM Forests Pty Ltd, Forests Commission . . . Pine plantation spraying for the control of unwanted growths of wattle etc and attack by wildlife has been discussed at a number of meetings. A yearly program has been put forward by APM for its requirements so that delay in operations, will be reduced to a minimum . . .
(2) Forests Commission. A letter of notification of the intention to spray was tabled by Mr Jack . . . for control of phasmatid insects in various areas of forest which were threatened. The area this year was reduced to 200 acres approximately. No objection from Committee.
MINUTES OF THE ONE HUNDRETH AND SEVENTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 20/2/76.
APM letter received from APM dated 28th Jan advising their intention to spray with 2,4,5-T noxious weeds in parts of the Parished of Callignee and Budgeree which were not advised in the letter of 26th June 1975 (Received and Approved).
Letter dated 13th Feb 76 was received from their Gippsland Manager of APM Forests advising of their proposal to spray certain areas in the Parishes of Allambee, Narrang, Nindoo, Glencoe South, Coolunggoolun and Holey Plains.
MINUTES OF THE ONE HUNDRETH AND EIGHTEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 9/4/76.
(4) Letters dated 13th and 20th Feb, 10th and 22nd and 31st March from APM Forests advising of their intention to spray certain areas in the Parishes of Allambee, Narrang, Nindoo, Glencoe South, Coolungoolum, Holey Plains, Yinnar, Jeeralang, Callignee, Jumbuk and Budgeree.
(5) Forests Commission - Letter dated 4 March received from Forests Commission advising its intention to spray land recently purchased in the Ryans Creek domestic water supply catchment for the planting of Pinus Radiata to reduce competition from grasses it is proposed to spray with Vorox A.A.
MINUTES OF THE ONE HUNDRETH AND NINETEENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 21/5/76.
2. APM Forests: Letter dated 30th April received from APM indicating that the firm intends to spray, two new areas in the Parish of Stradbroke, for pre-emergent weed control with the chemical Simazine. P2 To ascertain what effect a spray of 1.51 b per hectare with 2,4,5-T has on a stream . . . Run off will not occur until good rains have fallen, at which time the peak levels of chemicals getting into streams and reservoirs can be calculated. It was thought that because of the method of measuring the effect on streams it was not necessary to monitor every operation. It may be more beneficial if samples were taken from reservoirs instead of streams. . . This aspect brings about a concern that very heavy criticism could be leveled at an organization if it was thought that the communities health is being endangered . . . It was considered that spraying should go on for a considerable time because peaks are short but they are there. A thought must be given to what people will end up with in their drinking water . . . 2,4,5-T has been detected well downstream in the Ovens River and when it was traced it was learned that it came from Buffalo Park. Decision: a) To ask the Forests Commission to prepare a program of spraying and monitoring which would be able to show effects of chemicals consistent with distances away from point of application.
MINUTES OF THE ONE HUNDRETH AND TWENTY THIRD MEETING OF THE PESTICIDES REVIEW COMMITTEE 17/9/76.
Forests Commission Letter dated 12/8/76 concerning aerial spraying of two areas of pine plantations, with herbicides, totaling approx 600 ha of very steep rough country in the Yarram district. The herbicides to be used are Weedagol T.L. Plus and Gesaprim 500 FW mixed together in water to which the surfactant Plus 50 has been added.
Decision: To advise the Forests Commission that the Committee has no objection to the conduct of the spraying as set out.
MINUTES OF THE ONE HUNDRETH AND TWENTY FIFTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 26/11/76.
(1/1) APM Forests Pty Ltd letter dated 30th Sep 1976, received from APM advising the intention to use 1080 for vermin control in various areas of pine plantations. During discussion on this notification it was thought that the description of the animals to be controlled could be more explicit and be named. The word vermin should be illuminated from future use.
(2/1) APM Forests Pty Ltd. Letter dated 4/11/76 received from APM advising the intention to use 2,4,5-T early in December 1976, in various areas of pine plantations. Although there was no objection to the conduct of the work as indicated, it was considered that it was very doubtful if it was possible for the sprayer to achieve the objective of leaving natural drainage areas untouched. Monitoring in some of the difficult places are not possible and specific study areas should be established and definite techniques should be adhered to.
Decision (b) . . . but that more information, on the rates of the chemical used, and the type of aircraft used to obtain the result of a 20m width of non-sprayed drainage lines, would be appreciated. Item 31 2,4,5-T Papers and Queries Letter dated 9th Nov 1976, received from Commission of Public Health enclosing a copy of a letter from CCV requesting info on 2,4,5-T, also a letter from EPA enclosing a copy of similar letter requesting the same information.
MINUTES OF THE ONE HUNDRETH AND TWENTY SIXTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 25/2/77.
(1/1) APM Forests Pty Ltd letter dated 26th Jan received from APM requesting consideration of a spraying program with 2,4,5-T in a young plantation of pines in the Parish of Loy Yang. Decision: To advise APM that the letter was discussed and that, although this area does not appear on previous notifications the Committee does not object to the work being carried out as advised.
MINUTES OF THE ONE HUNDRETH AND TWENTY SEVENTH MEETING OF THE PESTICIDES REVIEW COMMITTEE 1/4/77.
Item. (1/1) APM Forests Pty Ltd: Letter dated 4th Nov received from APM which was discussed at 126th Meeting. As a result of the discussion it was generally agreed that APM was not researching 2,4,5-T after spraying. Decision: 26.11.76 (a) That Dr Craig prepares a factual paper, for consideration of a code of practice on intergrated sampling . . . (b) To advise APM of the Committees various decisions and its comments about the type of aircraft used and the rate of chemical used.
Introduction
The trend to intensive forest utilisation has led to adoption of clear-cutting practices and short crop rotation times on a large scale. In addition, regeneration of clear-cut sites is often with exotic trees such as the introduced softwood, Pinus Radiata or with more commercially desirable Eucalyptus species not native to the area. The end result of these practices will be a forest resource composed mainly of pine plantations and manipulated immature eucalypt forests managed in both cases as a mosaic of harvesting coupes each containing an even aged stand of trees. Where possible the coupes will be regenerated as monocultures - single species stands.
Management of even aged monocultures requires the weeding out of unwanted plants. In forestry this is being achieved increasingly by the large scale application of herbicides. The major “weeds” are the original native broadleaved plants (mainly Eucalyptus and Acacia species) and the perennial broadleaved noxious plants (such as the blackberries, Rubus species) which germinate on the harvesting coupe and compete with the regenerating forest crop. These unwanted plants are categorised as “woody weeds” and the favoured method of clearing dense stands from pine plantations or overgrown clear-cut sites prior to planting with commercial eucalypts is by aerial application of the butyl ester of 2,4,5-T in fuel oil (Flinn and Hopmans, 1977; McKimm and Hopmans, 1978). This practice is now thought to present very substantial risks to human health and natural ecosystems and led directly to the current suspension of the manufacture, distribution and use of 2,4,5-T in the United States (U.S.E.P.A., 1978; 1979a; 1979b) yet Australian forest managers seem unaware of the reasons.
The Discovery and Development of 2,4-D and 2,4,5-T
The plant growth hormone indolacetic acid, an auxin, was discovered in the 1930’s.
2,4-D was developed as a synthetic version in 1941 and it was found that an overdose touched off uncontrolled growth in broadleaved plants and killed them.
2,4,5-T was synthesized soon after and was found to have similar properties. These herbicidal properties were seen to be of great military value so 2,4-D, 2,4,5-T and many similar compounds were intensively tested and developed during World War II for use as chemical weopons by the U.S. Army Centre for Chemical and Biological Warfare at Camp (now Fort) Detrick, Maryland, U.S.A. (Whiteside, 1970).
Whiteside points out that the two herbicides were not tested in that role at the time for reasons outlined by George Merck, a chemist who headed the U.S. Biological Warfare Advisory Committee for the Secretary of War:
“Only the rapid ending of the war prevented field trials in an active theatre of synthetic agents that would, without injury to human or animal life affect the growing crops and make them useless.”
Thus 2,4-D and 2,4,5-T were originally developed for use as chemical weopons in biological warfare, not as agricultural herbicides.
After the Second World War ended, many chemicals developed and tested as chemical weopons were registered and marketed for civilian use. These included the herbicides 2,4-D and 2,4,5-T. At the time toxicological testing was not wel developed and, as the direct toxicity of the two herbicides appeared low in experimental animals, they were sanctioned for widespread sae and use by all relevant U.S.Governmental agencies. Their use for domestic agricultural and forestry purposes was heavily promoted. Extensive testing of the herbicides since 1960 has shown that this early faith was poorly based (U.S.E.P.A., 1978; 1979a; 1979b; Warnock and Lewis, 1978; Whiteside, 1970; 1977).
Chlorinated Phenoxy Acid Herbicides and their Contaminants
2,4-D and 2,4,5-T are the most widey used herbicides in the world and they belong to a group known as the chlorinated phenoxy acid herbicides that includes other herbicides such as 2,4-DB; 2,4-DES; 2,4,5-TP; and MCPA. Details can be found in the pubication “Herbicides of the Phenoxyacetic Acid Type” (AS No. 1175-1976, Standards Association of Australia, 1976).
2,4-D is an abbreviation of the chemical name 2,4-dichlorphenoxyacetic acid; similarly 2,4,5-T stands for 2,4,5-trichlorphenoxyacetic acid. The only difference between them is that 2,4,5-T has one more chlorine atom than 2,4-D.However, commercially each is synthesized from different raw materials and as a consequence, each contains a different set of unwanted contaminants. The contaminants present in mass produced agricultural and industrial chemicals are critical as it is generally uneconomic to remove them for normal use.
2,4,5-T and 2,4,5-TP are both manufactured from 2,4,5-trichlorphenol. 2,4,5-trichlorphenol is produced by reacting 1,2,4,5-tetrachlorobenzene with methanol and sodium hydroxide under high temperature and pressure. During this process, small amounts of 2,3,7,8 tetrachlorobenzo-para-dioxin (“TCDD” or “dioxin”) are inevitably produced. TCDD production can be controlled but not eliminated.
Thus 2,4,5-T and 2,4,5-TP are inevitably contaminated with 2,3,7,8-TCDD. This chemical is the most toxic substance known and it has caused several large scale poisonings (Whiteside, 1977) the best known being that at Seveso in Italy in 1976.Although the recent grave concern about 2,4,5-T and 2,4,5-TP has centered around this contaminant, 2,4,5-T with the lowest possible levels of TCDD has now been shown to produce adverse effects in experimental animals (U.S.E.P.A., 1978, 1979a; 1979b).
2,4-D and 2,4,5-T also contain a spectrum of other contaminants including other polychlorinated dioxins, various polychlorinated dibenzo-furans and polychlorinated diphenyl-ethers as well as traces of the original chemical reactants from manufacture (Ramel, 1978). Many of these could have as yet unknown adverse biological properties.
Chemical Warfare in Vietnam
From 1945 onwards testing and experimentation with herbicides as military weopons continued at Fort Detric and 1,200 compounds were assessed. By 1960 the U.S. military had settled on the use of four herbicidal sprays which were named from their colour codes:
Agent Orange:-50%n butyl ester 2,4-D; 50%n butyl ester 2,4,5-T
Agent Purple:-50%n butyl ester 2,4-D 30% n butyl ester 2,4,5-T 20% iso butylester 2,4,5-T
Agent White:-20% picloram 80% amine salt
Agent Blue:-65% cacodylic acid (dimethylarsenic acid); 35% inert salts
As part of the U.S. Vietnam war program, large scale application of herbicides commenced in 1961 and ended in 1971. In that time 4,119,960 acres of forest were defoliated and 468,559 acres of crops destroyed (Whiteside, 1970). The operation, known publicly as “Operation Ranch Hand” was officially designated by the code name “Operation Hades”. Agent Orange was the most extensively used herbicide and, as forests were the main target, the Aerial Spray Flight of the 309th Aerial Commando Squadron U.S.A.F. who conducted the campaigns, adopted the slogan “Only we can prevent forests” (Hersh, 1968).
When the extent of the damage done by herbicides in South Vietnam became known in the late 1960’s there was a massive backlash against U.S. chemical warfare from the U.S. and international communities. Scientists, technologists, servicemen, industrialists and politicians who had co-operated in the chemical warfare program in Vietnam suddenly found themselves accused of carrying out ecocide and genocide. As a result guilt reactions surfaced and attitudes towards herbicides hardened. Subsequently a team of scientists appointed by the National Academy of Sciences reported widespread ecological damage in Vietnam from the use of herbicides.
Owing to its widespread use, Agent Orange became synonymous with chemical warfare in Vietnam. Thus reactions to the civilian use of 2,4-D and 2,4,5-T became linked to reactions to the Vietnam War and its after effects. This factor, more than any other, has obstructed objective assessment of the risks presented by the two herbicides as many scientists, industrialists and politicians are basically intent on justifying their actions up to 1971.
Stories about adverse human health effects from the use of herbicides in Vietnam also started to circulate in the late 1960’s. In particular high rates of birth defects and spontaneous abortions were reported from areas heavily sprayed with Agent Orange. Serious questions suddenly emerged about the safety of the herbicides 2,4-D and 2,4,5-T to humans. The N.A.S. investigating team could not substantiate any adverse effects but stressed that basic epidemiological study requirements cannot be met in a population involved in a protracted state of war.
The Bionetics Report
The Bionetics report on 2,4,5-T was part of a series of tests carried out under a $2.5 million contract from the National Cancer Institute to screen more than two hundred chemicals, mostly pesticides, for birth deforming (teratogenic), cancer inducing (carcinogenic) and genetic (mutagenic) effects in laboratory mammals. These tests were carried out by the Bionetics Research Laboratories in Bethesda, Maryland.
In their tests 2,4,5-T did not appear to induce cancer in laboratory animals used and these results were released publicly in March, 1969. However, the results of the teratological tests were initially withheld even from members of the panel who were considering the teratogenic potential of pesticides. These tests had shown that 2,4,5-T caused birth deformities in rats and mice. Even when the results were eventually circulated to relevant governmental agencies, nothing was done to limit 2,4,5-T use. Finally some students working with Ralph Nader located a copy of the preliminary teratological report and told Harvard Biology Professor Matthew Meselson who obtained “bootlegged” copies from Washington officials in October, 1969. After reading the report Meselson was so alarmed that he contacted the Army and the White House and a collegue informed the press. As a result, Dr Lee DuBridge, President Nixon’s science advisor released a statement on 29th October, 1969, that said in part:
“…findings from a laboratory study conducted by Bionetics Research Laboratories indicated that offspring of rats and mice given relatively large oral doses of the herbicide (2,4,5-T) during the early stages of pregnancy showed a higher than expected number of deformities.”
This was, in fact, a gross understatement of the results - the 2,4,5-T used in the study caused excessive foetal mortality (80%) and high rates of birth abnormalities at the higher doses (100% at 46.4 mg/kg body weight and 90% at 21.5 mg/kg body weight) but there was excessive mortality and a threefold increase in birth abnormalities in survivors even at the lowest dose used (4.6%mg/kg body weight).
Once the Bionetics data on birth abnormalities and foetal mortality was released, action against 2,4,5-T seemed inevitable.The chemical industry cast around desperately for an explantation of the results that would not implicate 2,4,5-T itself. Dow Chemical Company scientists discovered that the 2,4,5-T used in the Bionetics study was obtained from the Diamond Shamrock Company in 1965. This company no longer manufactured 2,4,5-T in 1969 - thus the herbicide used in the tests was labelled as unrepresentative of the 2,4,5-T then in production.
Dow scientists also discovered that the 2,4,5-T used in the tests contained comparitively large amounts of the contaminant 2,3,7,8 TCDD or “dioxin” which is normally present in only trace amounts. Thus the 2,4,5-T used in the Bionetics study was also labelled as grossly contaminated with the most toxic chemical known. It was revealed that the 2,4,5-T used in the study contained 15-30 parts per million (ppm.) whereas the 2,4,5-T being produced in 1969 contained less than 1ppm TCDD.
Since 1969 TCDD levels have been reduced to less than 0.1ppm TCDD, but recent tests have shown this “pure” 2,4,5-T to be teratogenic in test mammals at dose levels down to 20 mg/kg body weight (U.S.E.P.A., 1978; V.C.C., 1978) and possibly even to 10mg/kg body weight (U.S.E.P.A., 1979a; 1979b).
As TCDD levels cannot be further reduced, it is now generally accepted that 2,4,5-T with its inevitable low level TCDD contaminant is teratogenic in test mammals with a no adverse effect level at about 20 mg/kg body weight. This was recognized by the Victorian Consultative Council on Congenital Abnormalities set up to investigate the Yarram cluster of birth abnormalities in 1975-76 (V.C.C., 1978).
This point has been misunderstood or misrepresented by many Australian forestry authorities. They apparently believe that only the Bionetics Report showed 2,4,5-T to be teratogenic, that the effects were due to the exceptionally high TCDD levels (“up to 50 ppm.”) and that since levels of TCDD were reduced to 0.1 ppm, or less 2,4,5-T has not been shown to be teratogenic.
Principles Governing Toxicological Evaluation
To safeguard public health it is essential to assess the effects that synthetic chemicals like 2,4,5-T have on humans. This is achieved in three ways:
(1) Epidemiology: Direct observation on human health where carefully collected statistics from populations exposed to the chemicals are compared to equivalent statistics from unexposed control populations. These data can be directly interpreted to set public health criteria.
(2) Laboratory Tests: Observation of biological effects on laboratory organisms exposed to set doses of the chemical compared to equivalent unexposed laboratory organisms. These data can only be very cautiously extrapolated to humans to set public health criteria.
(3) Exposure Analysis: Careful analysis of chemical pathways in the environment and measurement of actual flow rates. These data can then be used to calculate human exposure from possible absorption via skin contact, ingestion with food and drink, and inhalation with air. This information can then be used to set public health criteria in the light of the data from epidemiological or laboratory tests.
The biological effects that must be assessed include; toxic effects (systemic poisoning); carcinogenic effects (cancer induction); oncogenic effects (tumour induction); mutagenic effects (genetic changes); teratogenic effects (birth defect induction); embryotoxic effects (poisoning of the embryo); neurotoxic effects (brain or nervous system damage).
To evaluate the safety of a chemical, the U.N.F.A.O and W.H.O. have adopted a standard approach (W.H.O., 1972) which is widely accepted (N.H.& M.R.C., 1972; U.S.E.P.A., 1978; Victorian Pesticides Committee, 1966):
(1) Acceptance of a “no adverse effects level” (N.E.L.) established from epidemiological studies or in the course of some appropriately conducted long term tests of tests in laboratory organisms.
(2) Applications of an arbitrary “safety factor” (S.F.) which is in keeping with the nature of the chemical being tested, with the circumstances of its intended use, with the effect being tested, and the quality of the experimental studies available.
(3) Allocation of unconditional, conditional or temporary “acceptable daily intakes” (A.D.I.’s) where appropriate by dividing the “no adverse effects level” by the “safety factor”, i.e.:
A.D.I.=N.E.L. S.F.
For “pure” (i.e. low level TCDD) 2,4,5-T the teratogenic N.E.L based on laboratory animal experiments is accepted to be 20 mg/kg body weight per day (V.C.C., 1978; U.S.E.P.A., 1978) but it may need to be lowered to 10 mg/kg body weight per day in future (U.S.E.P.A, 1979a; 1979b).
For TCDD the teratogenic N.E.L. based on laboratory animal experiments is accepted to be 0.03 mg/kg body weight per day (V.C.C., 1978; U.S.E.P.A, 1978) but the U.S. E.P.A. has recently suggested there is no N.E.L. (U.S.E.P.A., 1979a; 1979b).
To set an adequate safety factor is more complex. Where the N.E.L. has been estimated from reliable epidemiological data (e.g. mercury on the population of Minimata in Japan) a small safety factor of 10 can be adopted (N.H. & M.R.C., 1972; W.H.O., 1972). Where the safety factor must be set from experimental animal data, a safety factor of at least 100 must be adopted as data from other animal species cannot be directly applied to humans (N.H. & M.R.C., 1972; V.P.C., 1966; W.H.O., 1972).
With teratogenic effects from laboratory tests, the safety factor must be even larger as thalidomide proved to be up to 700 times more potent in epidemiological studies on humans than in laboratory animal tests (Warnock and Lewis, 1978). Thus a safety factor of 1,000 is normally applied. For pesticides the W.H.O. recommend a safety factor of 2,000 as they have a strong chance for incorporation into human tissues (Whiteside, 1970). The safety factor recognized by the U.S.F.D.A and the U.S.E.P.A. is 2,000 (Whiteside, 1970; U.S.E.P.A, 1978). Strangely, the New Zealand Government enquiry into 2,4,5-T and birth deformities (N.Z. Department of Health, 1977) rejected the 2,000 safety factor but did not set an alternative - at best this would be 100. The Victorian Consultative Council on Congenital Abnormalities (V.C.C., 1978) did not even discuss safety factors but directly applied N.E.L. teratogenic data from laboratory tests to humans.
Thus for 2,4,5-T the safety factor to be applied to teratogenic N.E.L.’s from animal experiments is 2,000. For TCDD there may be no safety factor (U.S.E.P.A., 1979a; 1979b).
The A.D.I. for 2,4,5-T then, is the teratogenic N.E.L. - 2,000, at current values this is 0.01mg.kg body weight. This would need to be lowered to 0.005 mg/kg body weight if the N.E.L. is lowered. For TCDD there is probably no A.D.I.
The Victorian Consulatative Council on Congenital Abnormalities quoted an A.D.I. for teratogenic effects in humans of 20 mg/kg body weight for 2,4,5-T and 0.03 uu/kg weight for TCDD.
Uses of 2,4,5-T
Like 2,4-D, 2,4,5-T is similar to the indolacetic acid plant growth hormones (auxins) so it is often referred to as a hormone spray. In broadleaved plants (dicotyledonous angiosperms) such as wattles or eucalypts, an overdose of 2,4-D or 2,4,5-T causes uncontrolled tissue growth that kills the plant. The exact chemical basis of this effect is not yet clear but it has been likened to malignant cancer in animals (Warnock and Lewis, 1978). This lethal effect in broadleaved plants is not replicated in grasses (monocotyledonous angiosperms) such as wheat or rice, or in conifers (gymnosperms) such as pines.
Thus 2,4-D and 2,4,5-T are selective herbicides - they kill broadleaved plants but do not affect grasses or conifers.2,4-D is widely used on annual broadleaved weeds in grain crops, on grazing pastures, on recreation areas and on domestic lawns. 2,4,5-T is much more effective against “woody broadleaved weeds” - trees and perennial weeds such as blackberries and consequently has much more limited use.
Forestry Uses of 2,4,5-T
Most forestry “weed” problems involve unwanted broadleaved trees or perennial broadleaved plants, so 2,4,5-T is the most widely used herbicide. Major uses include the killing of unwanted broadleaved trees such as wattles in site clearance prior to replanting with commercially desirable eucalypts and the control of regenerating wattles and eucalypts and noxious weeds in pine plantations. (Dargavel and Hall, 1978; Flinn and Hopmans, 1977; McKimm and Hopmans, 1978).
Technical 2,4,5-T is available in two basic forms - as a water soluble amine salt or as a much more dangerous, volatile, oil soluble ester. The esters are the commonest form of forestry use, especially for spraying. Details of use of 2,4,5-T in Australian forestry can be found in Dargavel and Hall, 1978, (Australian and New Zealand pine plantations); Flinn and Hopmans, 1977, (Victoria); Forrest and Richardson, 1966, (New South Wales); and McKinnell and Butcher, 1973, (Western Australia).
In Victoria 2,4,5-T has its largest application “weeding” wattles from pine plantations and Flinn and Hopmans (1977) detail the practices. For low density wattle regeneration, manual applications of basal bark sprays or stem injections may be used.
However, the main method of application is low volume aerial spraying of the volatile butyl ester at the rate of 1.1kg 2,4,5-T in 50 litres of dieseline per hectare. Since this practice started in 1968, 17,981 hectares of publicly owned pine plantations have been treated this way - an average of 1,998 hectares per year (F.C.V. Annual Reports, 1968/69 - 1977/78). This represents 23.4% of the total publicly owned pine plantation area (76,860 hectares, F.C.V., Annual Report, 1977/78) or 2.6% per annum. No figures are available for privately owned pine plantations but the publicly owned resource is only about 50% of the state total so the total area treated since 1968 may be in the order of 36,000 hectares.
Hazards of Low Volume Aerial Spraying with 2,4,5-T
Low volume spraying is a euphemism for high concentration spraying where only 50-100 litres of diluent are used per hectare. In high volume spraying, 500-1,000 litres of diluent are used per hectare to spread the same amount of herbicide (McKinnell and Butcher, 1973).
Low volume aerial spraying of 2,4,5-T as practiced in forestry is exceedingly dangerous as a high concentration of the volatile butyl ester is applied to the target area as a dense mist from a height of about 30 metres. Spray drift and vapour drift are major problems and spraying cannot be carried out on windy days. The U.S.E.P.A. (1979a) records that 2,4,5-T spray drift has caused damage to susceptible plants 35 kilometres from a target area. Butcher and McKinnell (1973) record that air concentrations of 2,4,5-T down to 10 parts per billion (ppb.) kill susceptible plants (tomatoes) which works out to 0.0267 mg/cubic metre of air. Thus there is biological evidence of air concentrations of 2,4,5-T above 0.02mg/cubic metre 35 kilometres from a spray area. Is this concentration hazardous?
With regard to teratogenic effects, the acceptable daily intake (A.D.I.) is 0.01 mg 2,4,5-T/kg body weight. As a woman weighs 60 kg on average, the total A.D.I. is 0.6 mg. Each adult breathes about 30 cubic metres of air per day and 100% of the inhaled herbicide is absorbed (U.S.E.P.S., 1978). Thus on an A.D.I. basis the maximum allowable air level is 0.02mg/cubic metre. Spray drift up to 35 kilometres from a target area must therefore be considered hazardous to women in the child bearing age group.
The Australian National Health and Medical Research Council (N.H. & M.R.C.) set a maximum allowable air level of 10 mg/cubic metre of air for 2,4,5-T - 1,000 times the A.D.I. level for teratogenic effects; the level set for 2,4-D is 200mg/m3. (N.H. & M.R.C., 1975).
McKimm and Hopmans (1978) documented the amount of spray drift from a target area in a carefully controlled experiment on low volume spraying with 2,4,5-T at Narbethong carried out under optimal spraying conditions. They record from 30 metres only 65% (0.75kg/ha.) was recovered at ground level and they comment that this is in the upper range of expected recovery. In other words, at best, one third of the spray applied aerially moves immediately from the target area even in calm weather. Is this hazardous?
Of the 1.1kg of 2,4,5-T applied to each hectare during low volume aerial spraying, at least 35% or 0.385kg is lost to the general air mass as vapour and spray drift. With regard to teratogenic effects the maximum allowable air level is 0.02mg/cubic metre. The 0.385 kg of 2,4,5-T lost to the air during the spraying of each hectare of pines would contaminate 19,250,000 cubic metres of air to this level, or the air 641,667 women would breathe in one day.
In a decade 17,981 hectares of publicly owned pines have been aerially sprayed with 2,4,5-T. The spray and vapour drift during spraying (0.385 kg/ha.) is enough to contaminate the air 11.5 billion women would breathe in one day to above the A.D.I level.
Another major environmental hazard of low volume aerial spraying is volatisation of the spray from the target area in the weeks after spraying is completed. McKinnell and Butcher (1973) state that the butyl esters of 2,4,5-T should not be applied in hot weather and recommend spraying only when air temperature is below 24 degrees C. They record the butyle ester of 2,4,5-T has a vapour pressure of 7 mg/cubic metre of air at 30 degrees C; 16 mg/m3 at 40 degrees C; and 85 mg/m3 at 60 degrees C. To illustrate the highly volatile nature of the butyle ester, they record that the vapour pressure of the butoxyethyl ester is only 1 mg/m3 at 30 degrees C; and of the amine salt, 0 mg/m3 at 30 degrees C. In passing they comment that 2,4-D is even more volatile than 2,4,5-T.
With regard to teratogenic effects, the total A.D.I. is only 0.6 mg per adult woman. If the air were saturated with 2,4,5-T at 30 degrees C. (7 mg/m3), a woman would have to breathe the air for just over six minutes to exceed the risk level. Further, on an A.D.I. basis with regard to teratogenic effects, the maximum allowable air level is only 0.02 mg/m3. Clearly women in the vicinity of an area recently sprayed with the butyl ester of 2,4,5-T are at risk, especially during hot weather.
2,4,5-T Residues in Stream Water after Aerial Spraying
One other major environmental hazard with aerial spraying of 2,4,5-T is the contamination of runoff water from the target area. In 1972 the Forests Commission of Victoria continuously monitored 2,4,5-T levels in a small stream draining a spray site in a pine plantation at Myrtleford. McKimm (1972) reported that immediately following spraying low and quite acceptable concentrations of 2,4,5-T were found, and this condition obtained until the first rain after spraying, when the concentration in the stream rose rapidly. No figures were given but the report implied that after rain the levels obtained were unacceptable i.e above the standard of 20 ug.litre (20 ppb.) set by the National Health and Medical Research Council.
In June 1973 the F.C.V. carried out a larger study in 1 335 hectare section of a pine plantation in a catchment of Clear Creek near Myrtleford. Four stream sample points were established at varying distances from the spray area and a total of 1,000 samples were collected over a ten day period. Major peaks in 2,4,5-T concentration occurred after rain, and lesser, relatively insignificant, peaks also occurred during spraying (McKimm, 1974). McKimm stated that 2,4,5-T concentrations were in excess of the upper limit of 20 ug/litre set by the N.H. & M.R.C. but he did not list values. In fact, at the sampling point immediately below the spray zone values of 75 ug/l were obtained during spraying and peaks up to 690ug/l were obtained after rain. Three kilometers downstream values of 135 ug/l were obtained during spraying and peaks up to 500ug/l were obtained after rain. Worse, for the sampling point immediately below the spray zone, of 83 readings made during the seven days after spraying, 48% (40) exceeded 20 ug/l.; 14% (12) exceeded 50 ug/l.; and 7% (6) exceeded 100 ug/l. These measurements indicated that there was a significant threat to streams in aerially sprayed areas, but nothing was done. Rather, two new monitoring programs were organised, one at Carboor near Myrtleford and another at Narbethong in the Central Highlands.
The study at Carboor wa carried out in 1977 on a spray site of 162 hectares in the Scrubby Creek catchment. After the pine plantation was sprayed concentrations of up to 4.2ug/l were measured in a culvert draining the target area, but in Scrubby Creek concentrations remained below 0.3ug/l. (McKimm and Hopmans, 1977). The Narbethong study was carried out in July 1977 on a spray site of 108 hectares in the Old Mill Stream catchment. After the pines were sprayed concentrations in the Old Mill Stream were all below 4.4 ug/l except for one value of 10ug/l measured on the seventh day after spraying (McKimm and Hopmans, 1977; 1978).These two studies convinced the Forests Commission that aerial spraying presents no real threat to water quality (Flinn and Hopmans, 1977).
Regulation of Aerial Spraying with 2,4,5-T in Victoria
Australian pesticide authorities regularly invoke circular arguments on public risk. Firstly they recommend spray concentrations and practices which according to theoretical calculations should protect public health. Next, when publicity is given to a particular risk, they state that if the pesticide is used in accordance with their recommendations the pesticide presents no risk and the calculations used to formulate the recommendations are then repeated to prove the point. The real problems however, are that pesticides are often not used according to recommendations; that statuatory controls are weak or non-existent; and that enforcement is poor.
From the sections on the hazards of low volume aerial spraying and residues of 2,4,5-T in stream water, it can be seen that the aerial spraying of the butyl ester of 2,4,5-T should only be carried out in cool, calm, dry weather.However, aerial spraying is a capital intensive business and growing seasons dictate spraying times. Thus aerial spraying schedules are organized mainly on business commitments and not climatic considerations. It is informative to examine the statutory controls.
The Aerial Spraying Control Act 1966 as amended in 1968, 1970 and 1978, is the relevant parliamentary Act. This Act does not limit spraying activities in areas where human populations or natural ecosystems can be threatened. In fact, the Act is primarily designed to protect private property and commercial crops.For example spraying may not be carried out in “hazardous areas”, but these are defined as areas carrying susceptible crops.
The Aerial Spraying Control Regulations 1966 as amended in 1968, 1969, 1971 and 1977, detail the statutory rules for enforcement of the Act. The Fourth Schedule lists eight herbicides, including 2,4-D, 2,4-DB, 2,4,5-T and 2,4,5-TP which must be used under special controls. These include a prohibition on aerial spraying with ester formulations over or within 8 kilometres (5 miles) of any hazardous area.
Thus the Aerial Spraying Control Act and Regulations recognize that spray and vapour drift of the esters of 2,4-D and 2,4,5-T and related products can cause damage to susceptible plants at distances of up to eight kilometers.
The Act and Regulations exert statutory controls over aerial spraying of 2,4,-D and 2,4,5-T where economic damage to crops can result but spraying near natural ecosystems or human habitation is not controlled. Such controls have been left to the “Code of Practice for Large Scale Application of Pesticides in Victoria” issued by the Premiers Department in December, 1966. The Introduction of the Code reads:
“All governmental agencies are required to consult with the Pesticides Review Committee before proceeding with the large scale application of pesticides. Additionally, commercial organizations, particularly those operating within forested areas are encouraged to seek the advise and approval of the Pesticides Review Committee.”
The Code of Practice has no statutory powers. Thus with respect to risks to human health and natural ecosystems there are effectively no legal controls.
Aerial Spraying Incidents in Victoria
Two recent incidents in South Gippsland illustrate the deficiencies of legal controls over aerial spraying. The first relates to the spraying of a property known as Brigadoon Park at Seaview with 2,4-D and possibly some 2,4,5-T on the 7th of October, 1977. Although the farmhouse, water storages, garden and residents were saturated with spray and the garden was destroyed, the spray pilot and spray firm could not be charged with any breach of the Aerial Spraying Control Act or Regulations. Eventually the company, Skyfarmers Pty Ltd, were taken to court on twelve charges relating to breaches of the Environment Protection Act, 1970. They were found guilty on four of the charges in a written decision on 6th February, 1979 and fined $1000 with $3,130.80 costs.
The second incident occurred at Leongatha on the 15th of January, 1979, when 200 patrons at a drive-in theatre were sprayed with the fungicide Polyram 2000 at 8.55pm. Patrons and theatre staff complained of irritation to the eyes, ears and nose but once again the pilot and spray firm did not breach the Aerial Spraying Control Act or Regulations so no charges could be laid. The theatre projectionist said that a south-easterly wind had blown the chemical onto the drive-in and added “I reckon it’s a crying shame to have a plane spraying the stuff virtually in the town.”
These two incident show clearly that recommended aerial spraying practices are not always followed and that as a consequence direct human exposure can result without breaching the Aerial Spraying Control Act or Regulations. While it is illegal to spray 2,4-D or 2,4,5-T within eight kilometers of a susceptible crop, it is legal to spray immediately adjacent to houses and towns, and accidental (or deliberate) spraying of human habitation does not constitute an offence under the Act.
If the proponents of the aerial spraying of pesticides are sincere about the effectiveness of their recommended precautions, they should back up their beliefs with strict statutory controls to protect public health.
Controls of 2,4,5-T in Australia
Technical aspects of pesticide use in Australia are under the control of the Australian Agricultural Council. Health aspects are controlled by the National Health and Medical Research Council (N.H. & M.R.C.) who recommend acceptable residue levels for food and water and also which poisons schedule a pesticide is to be placed in. The N.H. & M.R.C. can also recommend any special restriction to be placed on a pesticide. State government authorities are expected to follow N.H. & M.R.C. recommendations in establishing statutory controls.
The role of the N.H. & M.R.C. in assessing the teratogenic properties of 2,4,5-T bears close scrutiny as it explains why no restrictions on public exposure have been made in Victoria.
In 1972 at its 75th Meeting, the N.H. & M.R.C. “…considered recent reports of teratogenic abnormalities in mice and rats following administration of large oral doses of the weedicide 2,4,5-T.” No references were provided but this was probably the Bionetics Report. The Council made three unequivocal recommendations that:
(i) all persons exposed to 2,4,5-T in its manufacture and use should use special precautions, such as protective clothing, to ensure that skin absorption does not occur.
(ii) Women in the child bearing age group should not be exposed to 2,4,5-T.
(iii) The residues of 2,4,5-T in water supplies should not exceed 0.02 parts per million.
Thus the Council acknowledged that 2,4,5-T caused birth abnormalities in laboratory mammals and that there was a consequent risk to humans.
In 1975 at its 80th Meeting, the N.H. & M.R.C. “…considered the most recent reports of teratogenesis following the adminstration of large oral doses of 2,4,5-T and considerd that the available evidence indicated that the impurity tetrachloro-dibenzo-para-dioxin (TCDD) was the agent implicated in congenital abnormalities.” The statement was simply not true and is completely contradicted by the U.S. E.P.A. reports (1978; 1979a; 1979b) and the Victorian Government Yarram Enquiry (V.C.C., 1978). The N.H. & M.R.C. report concludes:
“Council therefore rescinded the recommendations on 2,4,5-T made at its Seventy-fifth Session.
“Council recommended that 2,4,5-T containing more than 0.1 ppm. should not be permitted for use as a herbicide in Australia and that there should be a maximum residue limit of 0.02 ppm. 2,4,5-T permitted in water.”
In summary, in 1972 the N.H. & M.R.C. actually recommended women in the child bearing age group should not be exposed to 2,4,5-T because of its teratogenic effects on laboratory mammals. The Council rescinded this recommendation in 1975 despite the fact that new studies on laboratory animals had confirmed the original results even for 2,4,5-T with levels of TCDD below 0.1 ppm.
Since that time the N.H & M.R.C. has not publicly commented on the demonstrated teratogenic properties of 2,4,5-T with low levels of TCDD on laboratory mammals. Instead they have shifted ground and are now maintaining that teratogenic effects have not been demonstrated in humans. For example, at the 85th Session in 1978 they stated “Council could find no substantiated scientific evidence of a causal link between the use of 2,4,5-T and human birth defects.”
The Council have now completely abandoned their cautious 1972 stand where they were prepared to prevent a possible human disaster by extrapolating the results of tests on laboratory mammals to humans and ban the use of 2,4,5-T where women in the child bearing age group could be exposed. Now the Council are going to wait for substantiated evidence of a human disaster before they will take action.
Even worse, when epidemiological studies showing adverse reproductive effects in women exposed to 2,4,5-T have been published, the N.H. & M.R.C. have rejected them without explaining publicly why they are unacceptable. For example, the U.S. E.P.A. report showing a high rate of miscarriages in women exposed to 2,4,5-T in Alsea, Oregon, from 1972 to 1977 (U.S. E.P.A., 1977a) and the University of Sydney report showing a direct correlation with 2,4,5-T usage and the incidence of neural-tube defects in babies born in New South Wales from 1965 to 1976 (Field and Kerr, 1979) were both rejected. On the other hand reports purporting to show no adverse effects (e.g. the Yarram Enquiry Report, V.C.C., 1978) appear to have been accepted without close scrutiny.
To overcome these problems, the N.H. & M.R.C. should be forced to estimate a no adverse effects level (N.E.L.) for teratogenic data on laboratory mammals; state what the appropriated safety factor for human exposure is for this data; and from these calculate an acceptable daily intake (A.D.I.) level for women in the child bearing age group. From the A.D.I., risks from exposure to 2,4,5-T can then be assessed.
The N.H. & M.R.C. are also responsible for the Poisons Schedule designation of pesticides. Of eight schedules, 2,4,5-T is designated under Schedule 6 (Anon, 1978):
“Schedule 6 - Substances or preparations of a poisonous nature which must be readily available to the public for domestic, agricultural, pastoral, horticultural, veterinary, photographic or industrial purposes for the destruction of pests”.
This schedule stresses that ready availability of 2,4,5-T must be preserved, and does not stress that there is any real threat to human health.
To summarize the above information, the N.H. & M.R.C. (1972) started off very concerned about the demonstrated teratogenic effects of 2,4,5-T on laboratory mammals and recommended severe limitations on its use to protect women in the child bearing age group. In 1975 the Council mistakenly reported that 2,4,5-T with TCDD levels below 0.1ppm. showed no teratogenic activity in laboratory mammals. Since that time they have not publicly admitted their mistake and have not commented on the demonstrated teratogenic effects of 2,4,5-T with levels of TCDD below 0.1 ppm. Rather, they have shifted ground and abandoned their original standard that if a chemical is teratogenic in laboratory mammals it presents an unacceptable risk to humans, and adopted a new standard saying that there is no risk to women until reproductive effects are substantiated from studies on exposed populations.
Such an approach from a public health body is completely unacceptable.
Controls of 2,4,5-T in Victoria
Although state authorities are expected to adopt N.H. & M.R.C. recommendations, the three recommendations on 2,4,5-T made by the Council at its 75th Session in 1972 were not acted upon by the Victorian Government. After the rescission of the 1972 recommendations by the 80th Session in 1975 and the adoption of the recommendation that TCDD levels be kept below 0.1 ppm., the Standards Association of Australia rewrote the existing “Standard for Herbicides of the Phenoxyacetic Acid Type” (AS. No. N50-1965) and reissued it in 1976 (AS. No. 1175-1976) to incorporate a limit of 0.1ppm. TCDD for 2,4,5-T. Australian Standards have no statutory powers, however, the new Standard AS. No 1175-1976 was incorporated into the Victorian Pesticides Regulations on the 6th July, 1977 (Government Gazette No. 58, 1977).
Thus the only government action taken to decrease the risk of birth abnormalities from 2,4,5-T in Victoria since it was discovered to have teratogenic effects in laboratory mammals has been to limit TCDD to 0.1 ppm or less.
Even here the action has not been dramatic. The Yarram Consultative Committee (C.C.V., 1978) reports that tests on the TCDD level in 2,4,5-T offered for sale in Victoria over the last two years averaged 0.06ppm, and one sample reached 0.2 ppm. The U.S. E.P.A. (1979a) reports that in 16 recent samples of 2,4,5-T from five manufacturers in the U.S., TCDD levels ranged from not detectable (below 0.01 ppm.) to a maximum of 0.025 ppm. Further, the U.S. E.P.A. (1979b) reports that 8 recent samples of 2,4,5-TP from two manufacturers had TCDD levels from 0.012 to 0.024. Thus the maximum TCDD level measured for Victorian samples is eight times the U.S. maximum, while the Victorian average is two and a half times the U.S. maximum.
Trade Union Action
The seriousness of the risks associated with the use of 2,4,5-T has been realized by the Victorian Trade Unions. In February, 1979, the Victorian Trades Hall Council passed a resolution banning the handling and use of 2,4-D and 2,4,5-T until the State Government introduces and properly enforces regulations that protect workers health and public exposure. The V.T.H.C. listed seven points that must be covered in such regulations - including the three recommendations passed by the N.H. & M.R.C.’s 75th Session in 1972 that were rescinded by the 80th Session in 1975.
TABLE 1
2,4,5-T Usage in State Softwood Plantations 1969 - Area Sprayed and Amount of Herbicide Used.
In 1969-70, 271 hectares (a) were sprayed with a total of 289 kilograms a.i (b) used
In 1970-71, 1,436 hectares were sprayed with a total of 1,580 kilograms a.i used.
In 1971-72, 2,401 hectares were sprayed with a total of 2,641 kilograms a.i used.
In 1972-73, 2,798 hectares were sprayed with a total of 3,074 kilograms a.i used.
In 1973-74, 3,816 hectares were sprayed with a total of 4,198 kilograms a.i used.
In 1974-75, 2,486 hectares were sprayed with a total of 2,735 kilograms a.i used.
In 1975-76, 1,915 hectares were sprayed with a total of 2,106 kilograms a.i used.
In 1976-77, 1,107 hectares were sprayed with a total of 1,218 kilograms a.i used.
In 1977-78, 1,751 hectares were sprayed with a total of 1,926 kilograms a.i used.
In this time 17,981 hectares were sprayed in State Plantations throughout Victoria, using a total of 19,780 kilograms.
MEAN per annum 1,998 hectares. 2198 kilograms.
(a) Forestry Commission of Victoria Annual Reports 1969-70 to 1977-79.
(b) Calculated at rate of 1.1 kgm. per hectare.
Actions Against 2,4,5-T in the United States
Since the release of the Bionetics findings in 1969, 2,4,5-T 2,4,5-TP and other pesticides manufactured from 2,4,5-trichlorphenal have been the subjects of attempts to severely restrict or cancel their registrations for use owing to the inevitable presence of 2,3,7,8-TCDD. The early actions, published under Pesticide Registration (PR) Notices PR 70-8; PR 70-11; PR 70-13 and PR 70-22 in 1970 included suspension or cancellation of the following uses of 2,4,5-T:
1. All uses in lakes, ponds or in ditch drains.
2. Use around the home, recreational areas and similar sites.
3. All uses on food crops intended for human consumption.
On the 7th May, 1971, the U.S. E.P.A. committee recommended the use of 2,4,5-T be permitted on forests, rights-of-way and range-lands provided:
1. All 2,4,5-T be below 0.1 ppm. TCDD
2. 2,4,5-T be applied only once per year per site.
3. 2,4,5-T not contaminate areas where it could contact humans.
The U.S. Department of Agriculture (PR 70-22) reported that toxic chlorodioxins (such as TCDD) were always present as contaminants in basic material used in formulating 2,4,5-T. As a consequence the U.S. E.P.A. initiated action against the herbicide to cancel its registration. Dow Chemical Company obtained an injunction against the E.P.A. to stop the action on 1st July, 1972 but this was overturned in 1973.
On the 20th July, 1973, the U.S. E.P.A. filed a notice of intent to hold a hearing on the cancellation of all uses of 2,4,5-T in 1974 under the relevant Federal Act. This action was expanded on 10th May, 1974, to include all insecticides and herbicides made from 2,4,5-T trichlorphenal. However, the U.S. E.P.A. withdrew the cancellation hearings on 24th June, 1974, due to their inability to monitor dioxin. Instead, the E.P.A. held a Dioxin Conference on 25th and 26th July, 1974, and the “Dioxin Implementation Plan” (D.I.P.) was initiated. This was mainly a monitoring program and the move was strongly condemned by some (Whiteside, 1977).
Finally, as the first serious step in canceling the registration of 2,4,5-T, the U.S. E.P.A. issued a “Rebuttable Presumption Against Registration and Continued Registration of Pesticide Products Containing 2,4,5-T” or “RPAR” (Federal Register, Vol. 43, No. 78, 21st April, 1978). The Rebuttable Presumption criteria on which action was taken were:
1. “There is sufficient evidence to indicate that 2,4,5-T containing TCDD at levels as low as 0.05 ppm. and TCDD alone can produce ongenic effects in mammalian species. Since 2,4,5-T, as currently formulated, contains TCDD (at a maximum amount of 0.099 ppm.), a rebuttal presumption against registration of 2,4,5-T products has arisen because of the oncogenic effects of 2,4,5-T and TCDD.”
Thus 2,4,5-T and/or its contaminant TCDD are presumptive cancer risks in humans.
2. “2,4,5-T containing TCDD, 2,4,5-T without detectable TCDD and TCDD alone, produce fetotoxic and teratogenic effects in mammals.”
Thus 2,4,5-T and/or its contaminant TCDD are presumptive teratogenic and abortificant agents in humans.
3. “With regard to reproductive effects in mammals, an ample margin of safety does not exist for the population at risk (women of child bearing age) for dermal and inhalation exposure and for cumulative oral, dermal and inhalation exposure to both 2,4,5-T and TCDD.”
Thus exposure to 2,4,5-T in its normal registered uses is not safe for women in the child bearing age group.
As a result of information collected under the RPAR process, the U.S. E.P.A. took the strongest action possible against a registered pesticide on the 28th February, 1979 when it issued an “Emergency Suspension Order” for 2,4,5-T and 2,4,5-TP. The Order cited the 1978 criteria plus the result of an epidemiological study on the frequency of spontaneous abortions of women living in the Alsea area of Oregon where extensive aerial spraying of pine forests with the butyl ester of 2,4,5-T takes place every year. The study examined the frequency of spontaneous abortions during the first twenty weeks of pregnancy for women living in Alsea compared with data for women living in a non-exposed control area. For the six year period 1972 to 1977 there was a statistically significant increase in spontaneous abortions for the women in Alsea and the excess numbers in Alsea were seasonal and inevitably occurred shortly after the use of 2,4,5-T on pine forests in the area to kill broadleaved woody weeds.
The Emergency Suspension Order immediately halted the distribution, sale and use of 2,4,5-T and 2,4,5-TP in U.S. forests, rights-of-way and pastures as an imminent hazard to humans existed from the next forestry spraying season.
These U.S. actions were investigated by the Australian N.H. & M.R.C. in March 1979. A ten member committee of the Council found:
“The (U.S.) report did not substantiate the conclusions therein nor did it provide a basis for concluding whether 2,4,5-T causes or does not cause an increase in spontaneous abortions.”
These findings were accepted by the N.H. & M.R.C. Session in June, 1979 and the Chairman of the Commonwealth Health Department commented that the 2,4,5-T controversy was “…a comedy of errors except there is little humor in it.”
The credibility of the Council’s findings on the Alsea report, however, were suspect in the light of the 1975 rescission of the 1972 recommendation relating to the teratogenic effects of 2,4,5-T on laboratory mammals. Even more damaging was the revelation on 23rd May, 1979, that the N.H. & M.R.C. had similarly rejected an epidemiological study “Investigation of a possible association between the use of the herbicide 2,4,5-T and the incidence of neural tube defects in New South Wales” in December, 1978. This study, carried out by Dr B. Field and Professor C. Kerr of Sydney University had shown a direct correlation between 2,4,5-T usage and the incidence of neural tube defects in babies born in New South Wales from 1965 to 1976. A revised version was submitted to the Council early in 1979 but it was also rejected and the Council commented on May 24th, 1979:
“…the arguments it contained did not stand up to analysis because of serious deficiencies in statistical reasoning which created major doubts as to the validity of the conclusion reached.”
A summary of the report was published in The Lancet on June 23rd, 1979 (Field and Kerr, 1979) and this shows that the scientists were very cautious in drawing conclusions from their work. The method they used to gather and analyse data had previously been used to test and disprove Renwick’s theory that potato blight was causally associated with neural-tube defects without question. Further the scientists stated: “Our data and the record-linkage nature of analysis cannot be taken as direct evidence of any causal association involving 2,4,5-T”. The major point they made was that further retrospective analyses should be undertaken in other countries to throw some light on the significance of seasonal events in the origin of neural tube defects, and that the U.S. emergency suspension of 2,4,5-T provides a chance for a prospective trial in the Alsea area and elsewhere to see if the incidence of spontaneous abortions goes down after 2,4,5-T spraying ceases.
The action of the N.H. & M.R.C. in rejecting these two epidemiological studies so emphatically is puzzling as they have not publicly subjected any other studies on 2,4,5-T to such treatment. In the light of the Council’s abandonment of their