Industry Task Force II on 2,4-D Research Data Members: Nufarm Ltd. - PowerPoint PPT Presentation

Industry Task Force II on 2,4-D Research Data Members: – Nufarm Ltd. (Australia) – Dow AgroSciences (USA) – BASF (Germany) – AGRO-GOR • PBI-Gordon Corp. (USA) • Atanor, S.A. (Argentina)

Canada 2,4-D Registration History  First Registered in 1947: – Used primarily on cereal crops (barley, wheat) – Domestic turf label uses, three-way formulations (Killex, Par 3) and granular fertilizer/herbicide mixtures  Residue studies submitted in 1970s  Re-evaluation initiated in 1980  New GLP studies submitted in 1990s  Label improvement program 1994  PMRA re-evaluation of turf to be completed 2002

2,4-D Worldwide Data Package* Number of Technical Studies Submitted  Ecotoxicology > 180  Environmental Toxicology > 150  Environmental Fate > 142  Crop Residue > 100  Chemistry > 100  Toxicity of off target plants > 60 > 732 * 2,4-D Technical acid, esters (EHE, BEE IPE) and amines (DMA, TIPA, IPA, DEA)

2,4-D Worldwide Data Package Number of End-Use Studies Submitted  2,4-D and 2,4-D mixture labeled end-use products. (acute toxicology, chemistry, stability, etc. studies) >12,000  Total Research studies in data package: >40,000

2,4-D Peer-Reviewed Published Papers  Toxicology and Ecotoxicology > 4,000  Environmental Fate > 1,000  Other: Chemistry, Residue, etc. > 200  Epidemiology 140 – Epi papers pertinent to 2,4-D

Conclusions of Review Panels on 2,4-D USDA/NAPIAP University Minnesota School of Public Health Review, 1996  “ No scientifically documented human health risks, either acute or chronic, exist from the approved uses of phenoxy herbicides.”  US EPA 2,4-D Toxicology End Point document, 1996 “ 2,4-D is non-carcinogenic, non-mutagenic and non- teratogenic.”  US EPA Carcinogenicity Peer Review Committee (4th review), 1997 “2,4 - D should remain a Group D Compound.”  World Health Organization (WHO/FAO) 2,4-D Tox Monograph, 1996 “There was no evidence of carcinogenicity.”  Handbook of Pesticide Toxicology, Chapter 72, 2001 “ The extensive database of metabolic, toxicological, and epidemiological studies on 2,4-D has provided no evidence that 2,4-D poses any health risk to humans when used according to label instructions.”

Conclusions of Review Panels on 2,4-D  Garabrant et al ., Univ. of Michigan School of Public Health, Review of 2,4-D Epidemiology and Toxicology, Critical Reviews in Toxicology, 2001 (in press). Abstract: “The scientific evidence of humans and animals relevant to cancer risks, neurologic disease, reproductive risks, and immunotoxicity of 2,4-D was reviewed. Despite several thorough in vitro and in vivo animal studies, no experimental evidence exists supporting the theory that 2,4-D or any of its salts and esters damages DNA under physiologic conditions. Epidemiologic studies provide scant evidence that exposure to 2,4-D is associated with soft tissue sarcoma, non- Hodgkin’s lymphoma, Hodgkin’s disease, or any other cancer. Overall, the available evidence from epidemiologic studies is not adequate to conclude that any form of cancer is causally associated with 2,4-D exposure. There is no human evidence of adverse reproductive outcomes related to 2,4-D. The available data from animal studies of acute, subchronic and chronic exposure to 2,4-D, its salts and esters show unequivocal lack of systemic toxicity at doses that do not exceed renal clearance mechanisms. There is no evidence that 2,4-D in any of its forms activates or transforms the immune system in animals at any dose. It is unlikely that 2,4-D has any neurotoxic potential at doses below those required to induce systemic toxicity.”

What Do We Know About 2,4-D Toxicology?  Large number of up-to-date studies available  Moderate to low acute toxicity  Sub chronic effects generally limited to high doses  Low reproductive toxicity  Does not cause birth defects  Chronic effects generally limited to high doses  2,4-D does not cause cancer in animals  Does not cause genetic damage  Low potential to cause neurotoxicity  Various forms of 2,4-D show equivalence  2,4-D meets safety standards for today and beyond

The Precautionary Principle  In Canada, pesticides are regulated on the basis of the Precautionary Principle: – “Fundamentally, the whole approach to pesticide regulation is precautionary. No pesticide may be used in Canada unless its health and environmental risks and its value have first been determined to be acceptable.” Source: http://www.hc-sc.gc.ca/pmra-arla/english/pdf/hlawns/hl-GovtResp-e.pdf  These compounds are well studied, their effects are well known  The evidence of “harm” is not compelling  The effects, even on the intended target pests, are rapidly reversible

How Anti-Pesticide Activists Present the Epidemiology of 2,4-D Example 1 Selective Science (a) Hoar et al. , Agricultural herbicide use and risk of lymphoma and soft tissue sarcoma, JAMA, 256(9), 1141-1147, 1986. (b) CORRECTION, JAMA 256(24), 1986. (c) Zahm et al. , A case-control study of non- Hodgkin’s lymphoma and the herbicide 2,4-D in eastern Nebraska, Epidemiology, 1:349-356, 1990. (d) Cantor et al. , Pesticides and other agricultural risk factors for non- Hodgkin’s lymphoma among men in Iowa and Minnesota , Cancer Research, 52:2447-2455, 1992. (e) Cantor et al , Letter to the Editor, Cancer Research, 53:2421, 1993.

How Anti-Pesticide Activists Present the Epidemiology of 2,4-D Example 2 Selective Science (a) Wigle, Morrison et al ., Mortality study of Canadian male farm operators: non- Hodgkin’s lymphoma mortality and agricultural practices in Saskatchewan, JNCI, 82, 575-582, 1990. (b) Morrison, Wigle et al ., Non- Hodgkin’s lymphoma and agricultural practices in the prairie provinces of Canada, Scand J Work Environmental Health, 20, 42-47, 1994.

Natural vs. Synthetic The CBC Solution  Aqueous extract of rhubarb leaves. “Kills all kinds of bugs”*  Toxicity: – Tested positive for mutagenicity (Ames Test) – Oxalic acid is key component (LD 50 = 375). Oxalic acid disrupts estrus cycles when fed to rats, thus an “endocrine disruptor” – Is a contact sensitizer (may cause asthma) – Never tested for carcinogenic effects. – Never tested, but believed toxic to butterflies, ladybugs, earthworms and birds. * Source: CBC Web Site

Natural vs. Synthetic The CBC Solution - Since it is a known: - mutagen - endocrine disruptor - sensitizer - It could never be registered as a pesticide - Added warning: - “If ingested, may cause heart failure and death.”* * Source: CBC Web Site

Natural vs. Synthetic  Poisonous plants, including rhubarb leaves, rank fourth (behind cleaners, analgesics and cosmetics) as the substances most frequently involved in human exposure to poisons, and well above pesticides.  Most victims of poisonous plants are children. Of the almost 2 million calls a year received by the U.S. Poison Control Centers, only 3.8 percent involve pesticides.* *Source: Annual Report of the American Association of Poison Control Centers National Data Collection Service.

Turf Pesticides Worldwide  Restrictions / ban use of turf pesticides: - Canada  Discussions only at legislative level but no action: - Sweden - Denmark - Spain  No other country reporting municipal, state or federal restriction or ban for 2,4-D or any other pesticide used on turf.

Toxicity x Exposure = Risk “The Dose Makes the Poison”