Overview: Pesticide Chronic Health Hazards

1. Overview: Pesticide Chronic Health Hazards Lynn R. Goldman, MD, MPH Johns Hopkins Bloomberg School of Public Health

2. Types of Exposure to Pesticides

3. Pesticide morbidity • According to WHO, 1-5 million acute pesticides poisonings per year; at least a million hospitalizations. Numbers are questionable. • Agricultural incidents often involve children and teens. • Poisoning incidents in developing countries often involve the organophosphates, carbamates, paraquat and diquat • Pesticides poison between 1 and 3 agricultural workers per 100 • risks are not estimated Chronic and subchronic

4. Defining Pesticide Chronic Risks • Challenges • Hundreds of chemistries, thousands of product formulations • Relative shortage of human data and need to extrapolate from toxicology studies • Many potential exposure scenarios globally

5. Historical Overview (US)

6. 1947: FIFRA • Enacted in 1947 • Initially a consumer protection statute (for farmers)

7. 1962: Silent Spring • One of the most sinister features of DDT and related chemicals is the way they are passed on from one organism to another through all the links of the food chain." • Rachel Carson, 1962

8. 1970s • FIFRA transferred to EPA in 1972 • Bans/severe restrictions on DDT, aldrin, dieldrin, endrin, chlordane, heptachlor, toxaphene, DBCP, EDB and other highly chlorinated and brominated pesticides. • Most lead, arsenic and thallium pesticides were banned/severely restricted as well • Usage of other insecticides, e.g., organophosphates and carbamates, increased sharply

9. 1980s: Signs of trouble • Dioxins contaminating Agent Orange • In the 1970s, DBCP caused sterility among male pesticide-manufacturing workers • 1980s, epidemic of bladder cancer in workers after exposure to chlordimeform, first registered for use in the United States in 1968. • 1960s through 1980s, epidemics of severe accidental pesticide-related poisonings due to organophosphate pesticides (e.g., with parathion, mevinphos)

10. Pesticides in the Diets of Infants and Children • 1993 Report from National Academy of Sciences National Research Council • Concluded that the EPA inadequately assessed hazards and exposures to children • Led to the enactment of the Food Quality Protection Act of 1996

11. FIFRA reform • 1972 Comprehensive reform establishes FIFRA as public health law and sets goals of reassessing older pesticides and protection of farmworkers • 1988 FIFRA amendments require evaluation of all pesticides, old and new, using a robust set of toxicological tests and modern analytical methods, on a schedule. Evaluations include stricter worker protection measures • 1992 EPA worker protection standard • 1996 FQPA requires assessment of risks to children, on a schedule and with new health based standards

12. Cumulative and Aggregate Risk • Aggregate Risk: The same pesticide with multiple exposure pathways (e.g., present in food, drinking water, and/or household products) • Cumulative Risk: Multiple pesticides that act via a similar mechanism (e.g., OP’s, triazines, organochlorines)

13. FQPA 10x Kids Factor • EPA is required to apply a 10X FQPA safety factor (in addition to the traditional 10X uncertainty factors for interspecies and intraspecies extrapolation) unless there are sufficient toxicity and exposure data to ensure that children will be safe

14. Reassessment of Pesticides under FQPA

15. Organophosphates & Carbamates • Insecticides: 40 OPs in the U.S. • Inhibit acetyl cholinesterase • Carbamates share mechanism of action • Acute and chronic toxicity • Specific concern re: developmental neurotoxicity • Food, lawn and household use pesticides (e.g., malathion, chlorpyrifos, aldicarb)

16. Developmental neurotoxicity of OPs • Are neurotoxic pesticides especially harmful to developing brains? • Certain neurotoxic chemicals (PCBs, lead and methylmercury) are 1000 fold more toxic to the developing brain than to adult animals. • EPA has called in data on developmental neurotoxicity of organophosphate pesticides. • OPs modulate DNA expression in the developing brain, possibly at levels below those that cause acetyl cholinesterase inhibition

17. Cumulative risk of OP’s • Recent draft EPA cumulative risk assessment is under review • Indicates that overall exposures to cholinesterase inhibiting pesticides are two times above regulatory limits for the upper 0.1% of kids • Assessment does not account for developmental neurotoxicity • Assessment employs a 3X FQPA factor, which many feel is inadequately protective

18. When will pesticides be “safe” under FQPA? • Food Quality Protection Act: Deadline for reassessments is 2006 • However, they are going after the riskiest pesticides first and initial actions have focused on kid’s foods • Meanwhile, baby food companies and others are voluntarily moving away from organophosphates and other pesticides that are likely to be problematic

19. Hazard Data • Reregistration of pesticides (1988 law); so called “REDs” are available on line (Reregistration Eligibility Documents) • Tolerance reassessments (1996 law); EPA must publish a finding showing how it concluded “a reasonable certainty of no harm” (Federal Register) • EPA FIFRA Science Advisory Panel (www.epa.gov/pesticides)

20. Pesticides in developing countries

21. Pesticide consumption, metric tons (Mt) per 1,000 km2 land area (Source: FAO/WHO)

22. Pesticide Consumption and Rural Population

23. Average annual consumption (in metric tons) of chlorinated hydrocarbon, organophosphate, and dithiocarbamate pesticides (1990-1998)

24. Developing countries consuming more than 200 metric tons/year of organophosphate pesticides, 1990-98. (Source: FAO data)

26. Occupational Concerns • Farmers in developing countries generally are unaware of the short and long-term hazards associated with exposures to many pesticide products. • Advanced technologies such as chemical pesticide application require knowledge that goes beyond traditional agricultural practices.

27. Frequently documented unsafe practices • Poor knowledge and understanding of safe pesticide use practices and deficiencies in safety training are the norm among the developing countries. • Careless handling during preparation and application, • Use of pesticides in concentration in excess of requirements, • Consumption of food and beverage while working, • Lack of personal hygiene, • Laxity of safekeeping of the chemical, and • Careless disposal of empty pesticide containers.

28. Poor maintenance facilities for spray equipment has led to hazardous contamination and use of pesticide mixtures • Occupational poisoning occurs largely during spraying, mixing and dilution of pesticides. • The use of malfunctioning or defective equipment is an important factor contributing to accidental acute poisoning among agricultural workers. • Poverty leads to a lack of availability of personal protective equipment. Even where available, it may be avoided due to heat related discomfort and heat stress.

29. Child Labor in Agriculture • Given that most of the working children in the developing nations are agricultural workers and the use of agricultural pesticides is widespread, their exposure to hazardous chemicals can be expected. • Various case studies and outbreak reports have reported child workers’ exposure to hazards associated with the inappropriate use of agrochemicals; no long term follow-up has been done of these children

30. Non-occupational pesticide concerns • Bystander poisonings • Contamination of soil in areas where mixing and loading occurs • Especially high levels of community pesticide exposure in developing countries

31. Factors resulting in excess levels in communities • Excessive use • Uncontrolled patterns of spraying, • Open houses located to fields, • Lack of washing facilities, Improper storage of pesticides in homes (under beds, on kitchen shelves), • Improper use of empty containers for the storage or transfer of water, vegetable oils or food, • Field re-entry delay intervals after spraying are not usually observed by workers or residents in these areas. • Not observing intervals between the last pesticide application and harvesting and eating the produce, • Hand washing of clothes worn by farmers during pesticide applications

33. POPs • Environmental and food contamination, human exposure, and potential health effects are the legacy of historical use of POPs in many developing countries. • Studies and ongoing monitoring of POP contamination and human exposure are limited to non-existent in most developing countries. • Children in the developing countries are most vulnerable; they are exposed to POPs not only through consuming contaminated foods but also in utero and in breast milk.

34. POPs Obsolete Stocks • POPs comprise of a significant portion of obsolete pesticide stockpiles in the developing countries. The cost of disposal of obsolete POPs is high and cannot be afforded by these poor developing countries.

36. Obsolete stocks health and environmental health concerns • Spills and leaks from containers can find their way into surface waters from runoff or into groundwater from leaching through soil. • Poor storage of obsolete stocks creates pathways to environmental contamination and human exposure. • Clearly, chronic illness, reproductive problems and birth defects as the result of such exposure would bring high long-term costs for individuals and communities. • There are many examples of children playing, livestock grazing, people working, cooking, drawing water and growing food around dumped and leaked pesticides.

37. Factors that lead to the accumulation of obsolete pesticides in developing countries • Product bans • Inadequate storage and poor stock management • Unsuitable products or packaging • Donation or purchase in excess of requirements • Lack of coordination between donor agencies • Commercial interest of private sector and hidden factors. (FAO Obsolete Pesticides Program, 1995b)

38. Pesticide Alternatives • Concerted efforts should be made by governments and pesticide industries to develop and promote: • integrated pest management systems • the use of safe, efficient, cost-effective application methods FAO Code of Conduct on Pesticides

39. Insecticides Aldrin Chlordane DDT Dieldrin HCH Heptachlor Hexachlorobenzene Lindane Methyl-parathion (some) Methamidophos Monocrotophos Parathion Phosphamidon Other Pesticides 2,4,5-T Captafol Chlorobenzilate Chlordimeform Dinoseb 1,2-Dibromoethane (EDB) Fluoroacetamide Mercury compounds Pentachlorophenol Pesticides initially in PIC

40. POPs Convention Pesticides • Aldrin • Chlordane • DDT • Dieldrin • Endrin • Heptachlor • Mirex • Toxaphene • Hexachlorobenzene

41. Insecticide alternatives • Pyrethroids • New chemistries • Biologicals (Bt, parasites, pheromones, genetically modified “plant incorporated protectants”)

42. The need for safer pesticides • "A truly extraordinary variety of alternatives to the chemical control of insects is available," she wrote. "Some are already in use and have achieved brilliant success. Others are in the stage of laboratory testing. Still others are little more than ideas in the minds of imaginative scientists, waiting for the opportunity to put them to the test. All have this in common: they are biological solutions, based on understanding of the living organisms they seek to control, and of the whole fabric of life to which these organisms belong." • Rachel Carson, 1962

43. SOEH book • Educate as to the chronic health hazards of pesticides, especially for new chemistries, new data on older pesticides • Reference manual and a companion to EPA’s book on Recognition and Management of Pesticide Poisoning (which covers acute effects) • Inform responsible decision making to prevent exposures to hazardous pesticides