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Chapter 5 – DFTD toxicology studies - the undone science

5.2 Why test for chemicals?

Tasmania is a small island with a population of approximately 512,875 persons as at 31 March 2013.4 The Tasmanian economy relies heavily on mining, its largest source of income, and forestry. The mining industry is worth $A1.3 billion a year to the economy whilst Tasmania supplies half of all Australian exports of woodchips, newsprint and writing paper, worth half a billion Australian dollars a year to the Tasmanian economy.5 Historically the mining and agricultural industries have contributed, through their practices, to the contamination of both soil and water in Tasmania. However, the more recent increase in eucalypt plantation forests, particularly in the northeast of the state, has, through its reliance on pesticides to protect seedlings and trees, substantially added to the contamination problem. In plantation forests there is also an increased need for aerial application, thus dispersing chemicals over a much wider area at greater heights,

4 Tasmanian government, Department of Treasury and Finance, 2013, Population. Available at:

http://www.treasury.tas.gov.au/domino/dtf/dtf.nsf/LookupFiles/Population.pdf/$file/Population.pdf last accessed 2 December 2013

5 Top 10 contributors to the Tasmanian economy. Available at:

http://www.tasmaniatopten.com/lists/economic_contributors.php last accessed 2 January 2013

with an increased potential for drift to non-target areas.6 There is also a higher maximum allowable rate for chemicals on plantations – e.g. atrazine: (8kg/hectare) compared to crops (2.5 kg/hectare). 7 Whilst it is acknowledged that both mining and agriculture may have historically contributed to environmental contamination in Tasmania, it is the more recent and substantial increase in plantation forests and their reliance on chemicals that is the focus here. This more narrow focus is also in response to the Scammell Report, which made a correlation in time and space between the increase in plantation forests, an increase in oyster health problems and the spread of devil cancer.

Public pressure to conserve native and old-growth forests, and the implementation in 1997 of Plantations for Australia: The 2020 Vision, has driven the ever-expanding plantation forest estate in Tasmania.8 Gunns Limited, the largest forest products company in Australia, has alone developed over 200,000 hectares of plantations in Tasmania over the last 25 years.9 A more recent driver of plantation forests was the plan to build a $2 billion pulp mill in the north of the state. The then Tasmanian Premier Paul Lennon engaged in undisclosed talks with Gunns Limited for its construction in 2003.10 It was to be the largest in the southern hemisphere and would have relied predominantly on plantation timber.1112

6 Primary Industries Standing Committee, 2002, Spray Drift Management, Principles. Strategies and Supporting Information, CSIRO Publishing, Collingwood Victoria. Available at:

http://www.publish.csiro.au/Books/download.cfm?ID=3452 last accessed 2 January 2013

7 Jenkin BM & Tomkins B, 2006, Pesticides in Plantations, Forest and Wood Products Research and Development Corporation, Melbourne, Victoria, Australia

8 Planatations 2020, Plantations for Australia: The 2020 Vision. Available at:

http://www.plantations2020.com.au/vision/ last accessed 6 May 2013

9 Gunns Limited, About Gunns. Available at: http://gunns.com.au/about-us/ last accessed 5 October 2013

10 ABC News, 2012, Timeline: The rise and fall of Gunns. Available at:

http://www.abc.net.au/news/2012-09-25/gunns-timber-company-rise-fall-timeline/4235708 last accessed 6 January 2013

11 Gunns Limited has since gone into receivership and administrators have been appointed. ABC News, 2012, Timeline: The rise and fall of Gunns. Available at:

http://www.abc.net.au/news/2012-09-Plantation forests are now located in 44 of the 48 river water catchments in Tasmania.13 These plantations are monocultures of eucalypts, which rely on synthetic fertilizers and pesticides to maintain high yields.14 Establishing the eucalypt plantations is dependent on the use of poisons to control browsing mammals, herbicides to control weeds, fungicides to control pathogens and insecticides to control insect attack.15 Chemicals used in Tasmanian plantation forests are included in an 18-page list of products registered by the national regulator, the Australian Pesticides and Veterinary Medicines Authority (APVMA).16 However even this extensive list omitted terbuthylazine, fluazifop and 1080, all known to be used in Tasmanian plantation forests.17 The chemical compound 1080 (sodium monofluoroacetate) is used as a poison in baits distributed in plantations to protect the eucalypt seedlings from browsing native animals.

Although the Tasmanian devil lethal dose of 1080 is high compared to other native species, researcher Helen L Statham noted that marsupial carnivores are the first native

25/gunns-timber-company-rise-fall-timeline/4235708 last accessed 3 January 2013 The outcome for the proposed pulp mill, which was vehemently opposed by many Tasmanians, is currently unknown.

12 In the Supreme Court of Victoria at Melbourne Commercial and Equity Division Commercial Court List G, 2012, In the matter of Gunns Plantations Limited. Available at:

http://www.gunns.com.au/Content/uploads/documents/Court%20Orders%2019%20December%202012.p df last accessed 2 January 2013

13 Bendor M, Parr I & Goninon C, 2008, The Tasmanian River Catchment Water Quality Initiative: The development and evaluation of a methodology for identify the nature and extent of chemical pesticide usage in Tasmanian river catchments, Tasmania, Department of Primary Industries and Water, Hobart, Tasmania

14 Altieri MA, nd. Modern Agriculture: Ecological impacts and the possibilities for truly sustainable farming. Available at: http://nature.berkeley.edu/~miguel-alt/modern_agriculture.html last accessed 10 May 2013

15 Green G, 2004, Plantation Forestry in Tasmania, Timber Workers for Forests. Available at:

http://www.twff.com.au/documents/research/pftpt4.pdf last accessed 2 January 2013

16Australian Government Senate Rural and Regional Affairs and Transport Legislation Committee, Answers to Questions on Notice, Budget Estimates May 2009, Agriculture, Fisheries and Forestry, Australian Pesticides and Veterinary Medicines Authority, Response to Question on Notice, Question:

APVMA06 Attachment 1, Hansard. Australian Government Senate, Canberra.

17 ibid.

species to show signs of 1080 poisoning. 18 The long-term effects of the poison on Tasmanian devils have not been studied.

Other chemicals designed to kill target species are also known to cause harm, such as endocrine disruption and cancer, to non-target species. Chemicals of particular concern include the triazine herbicides - atrazine, simazine and terbuthylazine - and the chemical paraquat, all used to kill weeds. Atrazine is a known endocrine disrupter in frogs19 and a suspected carcinogen in humans.20 Simazine and terbuthylazine, with almost identical chemical structures to atrazine, are suspected of having the same harmful effects although these suspicions are supported by fewer studies.21 The US EPA in a report on triazine cumulative risk, grouped atrazine, simazine, propazine and the metabolites desethyl-s-atrazine (DEA), desisopropyl-s-atrazine (DIA) and diaminochlorotriazine (DACT) as a group of chemicals with a common mechanism of toxicity i.e. ‘they act in the same way in the body – that is, the same toxic effect occurs in the same organ or tissue by essentially the same sequence of major biochemical events’.22 This assessment is based on their ability to cause neuroendocrine and endocrine-related developmental, reproductive and carcinogenic effects. Paraquat, on the other hand, is acknowledged as the cause of serious ill health and even death in humans.23 In November 2012 an

18 Statham HL, 1996, Impact of 1080 on non-target species and priorities for research. A report to the Browsing Animal Research Council, Hobart, Tasmania

19 Hayes TB, Haston K, Tsui M, Hoang A, Haeffele C & Vonk A, 2003. “Atrazine-induced Hermaphroditism at 0.1ppb in American Frogs (Rana pipiens): Laboratory and field evidence.”

Environmental Health Perspectives 111(4), pp 568-576

20 MacLennan PA, E Delzell, N Sathiakumar, SL Myers, H Cheng, W Grizzle, VW Chen & Wu XC, 2002, Cancer Incidence Among Triazine Herbicide Manufacturing Workers, Journal of Occupational and Environmental Medicine 44(11), pp 1048-1058

21 US Environmental Protection Agency, 2006, Pesticides: Health and Safety 2006, Triazine Cumulative Risk Assessment and Atrazine, Simazine and Propazine Decisions; June 22, 2006, Available at

http://www.epa.gov/oppsrrd1/cumulative/triazine_fs.htm last accessed 7 March 2010

22 US Environmental Protection Agency Office of Pesticides Programs Health Effects Division, 2006, Cumulative Risk from Triazine Pesticides, US EPA, Washington, DC, p 2

23 Madeley J, 2002, Paraquat - Syngenta’s controversial herbicide. Available at http://www.evb.ch/en/p1300.html last accessed 29 August 2009.

Australian farmer died as a consequence of being sprayed with paraquat.24 Both atrazine and paraquat have been the focus of heated controversies between the manufacturer Syngenta and those who seek to minimise harm.

The consequence of this widespread use of chemicals in plantations has meant the implementation by DPIPWE of the Pesticide Water Monitoring Program, which tests for 16 pesticides at 47 sites every two months.25 Results of the findings are also published every two months. The first evidence of the potential for pesticides to contaminate surface water in Tasmania was made in the findings of a study led by Professor Peter Davies from the University of Tasmania in 1994.26 The authors found that between 1989 and 1992, 20 of the sampled 29 streams draining plantation forests contained detectable residues of the chemicals atrazine and simazine. Supporting these findings is the report Pesticide Use in Australia, which states that streams draining forestry land generally contain more pesticides than agricultural streams. 27 Contamination of surface and drinking water in Tasmania is ongoing with four pesticides detected in the latest survey.28

24 McKenna K, 2012, Lifelong farmer dies from toxic weedkiller, The Courier-Mail, 16 November 2012, p9 25 Tasmanian Government Department of Primary Industries, Parks, Water and the Environment, Water, Pesticide Monitoring. Available at:

http://dpipwe.tas.gov.au/water/water-monitoring-and-assessment/pesticide-monitoring last accessed 23 April 2014

26 Davies PE, Cook LSJ & Barton JL, 1994, Triazine Herbicide Contamination of Tasmanian Streams:

Sources, Concentrations and Effects on Biota, Australian Journal of Marine and Freshwater Resources Vol 45, pp 209-226

27 Radcliffe JC, 2002, Pesticide Use in Australia. Australian Academy of Technological Sciences and Engineering, Parkville, Victoria

28 Tasmanian Government Department of Primary Industries, Parks, Water and the Environment, Water, Latest Pesticide Water Monitoring Results. Available at:

http://dpipwe.tas.gov.au/water/water- monitoring-and-assessment/pesticide-monitoring/pesticide-water-monitoring-program/aschem-latest-results last accessed 23 March 2014

Chemicals used in Tasmanian plantation forests are registered for use by the APVMA, which also determines the use label. However, it is the responsibility of state governments to monitor and regulate chemical use, and in Tasmania this is the role of DPIPWE. Dr Marcus Scammell, marine ecologist, who investigated the contamination in Georges Bay (described in more detail in Chapter 9), in an interview with the Australian Broadcasting Commission’s (ABC’s) reporter Jocelyn Nettlefold, suggested that water contamination is perhaps the main way animals absorb chemicals.29

Reports of water contamination continue unabated in Tasmania and it is still a critical public and environmental health issue.30 Therefore, it would be appropriate for scientific research to be undertaken into the potential effects chemicals used in the environment have on Tasmanian devils. This would seek to determine if one or more chemicals, acting singularly or in synergy, are involved in the aetiology of the cancer. A full analysis of the regulation and use of chemicals in forestry plantations is given in Chapter 9. The potential for non-target species, such as the Tasmanian devil, to be harmed by environmental contaminants is discussed in the next section.