RISKS AND BENEFITS OF PESTICIDES FOR FUTURE GLOBAL FOOD DEMANDS

1. RISKS AND BENEFITS OF PESTICIDES FOR FUTURE GLOBAL FOOD DEMANDS Dr. Gerry Stephenson Department of Environmental Biology University of Guelph Guelph, Ontario, Canada Gerry.stephenson@rogers.com

6. HEALTH RISKS WITH PESTICIDES DEPEND ON PESTICIDE and HUMAN TOXICITY EXPOSURE

7. More women are choosing research careersin agriculture But this a poor illustration of how to dress when using a research sprayer

8. Applicators of unregistered pesticides in research Should wear full protective clothing

9. In industrialized countries, Most growers are trained and certified pesticide applicators

10. Fortunately, Mistakes and accidents like this are rare

11. Advances in sprayer technology are reducing risks For the applicator and for the environment

12. HAND-HELD PESTICIDE SPRAYERS ARE STILL USED IN NORTH AMERICA Especially in landscape situations How much protective clothing is required for safety?

13. Pesticides are commonly applied with hand held sprayers in “Developing countries” Notice the bare skin, especially the hands!

14. EXPOSURE PROBLEMS Aren’t limited to hand held equipment

15. HEALTH RISKS WITH PESTICIDES ARE A PREVENTABLE PROBLEM • Proper pesticide use rarely causes a health problem • Problems can be prevented by the continued development of even safer pesticides • Industrialized countries have effective regulatory, educational and training programs for applicators • These programs are expensive to maintain and will be a challenge to implement in developing countries

16. PESTICIDES CAN BE AN ENVIRONMENTAL RISK • Risk depends on • volume of use • persistence • mobility • non-target toxicity

17. EVIRONMENTAL CONCERNS ABOUT PESTICIDES 1960’s Today InsecticidesHerbicides

18. EVIRONMENTAL CONCERNS ABOUT PESTICIDES Spray Drift Early studies on 2,4-D drift More recent studies on glyphosate or clomazone drift

19. ENVIRONMENTAL CONCERNS ABOUT PESTICIDES PESTICIDE CONTAMINATION OF WATER Early concerns about 2,4-D, atrazine, metolachlor Less concern with new “low rate” pesticides

20. ENVIRONMENTAL CONCERNS ABOUT PESTICIDES SOIL RESIDUE CARRY OVER PROBLEMS Earlier studies with triazine herbicides More recent concerns with sulfonylurea or imidazolinone herbicides

21. NEW LOW-RATE HERBICIDES (<100 g/ha) • Are reducing environmental risks in general • However, soil residue carry-over concerns • are environmental problems for the farmers

22. ROTHAMSTEAD SOIL STUDY SHOWS EFFECTS OF PESTICIDES IN SOIL ARE REVERSIBLE 17 months after applying five pesticides per year for 20 years • no detectable pesticide residues • no differences in microbial activity • no effect on barley yield, as indicator crop Evans(IUPAC)1998

23. BENEFITS OF PESTICIDES -TO WHOM? _________________________________________ Numbers Chemical companies Very small Growers Small Consumers Large Society Vast

25. BENEFITS OF PESTICIDES -TO WHOM? ________________________________ Numbers Chemical companies Very small Growers Small Consumers Large Society Vast

26. Growers expect a $4 return on each $1 spent on pesticides Is this still true?

27. BANNING PESTICIDE USE IN THE USA • Would reduce agricultural output by 30% • At pesticide & commodity prices in 1997 • There would be a $3 to $4 return for each $1 • spent on pesticides • Fernandez-Cornejo et.al., 1998

28. Governments in a number of industrialized countries have set goals for reducing the use of pesticides in agriculture

29. FOOD SYSTEMS 2002 IN ONTARIO, CANADA • OBJECTIVES • To reduce total Kg of pesticide use by 50% by the year 2002 • While maintaining agricultural productivity • METHODS • Improved grower education, IPM and development of more alternatives

30. FOOD SYSTEMS 2002 • Reduction in Kg of agricultural pesticides between 1983 and 1998 • For all agricultural crops 38% • For maize (our largest crop) 48% • Reasons • Better grower education, IPM, alternatives • Shift to new “low-rate” pesticides

32. FOOD SYSTEMS 2002 Reduction in E.I.Q./ha between 1983 and1998 For all crops 34% For corn(maize) 40% The next survey is for this year, 2003

33. BENEFITS OF PESTICIDES -TO WHOM? ________________________________ Numbers Chemical companies Very small Growers Small Consumers Large Society Vast

35. BENEFITS OF PESTICIDES -TO WHOM? ________________________________ Numbers Chemical companies Very small Growers Small Consumers Large Society Vast

36. BENEFITS OF PESTICIDES -TO WHOM? ________________________________ Numbers Chemical companies Very small Growers Small Consumers Large Society Vast

37. SOCIETAL BENEFITS MINUS COSTS OF PESTICIDE USE IN THE USA • The annual use of $6.5 billion worth of pesticides • Prevents $26 billion in crop losses due to pests • About a $4 return per $1 spent on pesticides to the growers • Pimentel and Greiner, 1997

38. SOCIETAL BENEFITS MINUS COSTS OF PESTICIDE USE IN THE USA • Estimated indirect costs of pesticide use is $8billion per year (regulation, training, health & environmental losses) • $26 billion in benefits/$14.5 billion in costs equals about a $2 return to society for each $1spent on pesticides • Pimentel and Greiner, 1997

39. AGRICULTURAL PESTICIDE USE SAVES ENERGY HUMAN ENERGY FOSSIL FUELS

41. PESTICIDES SAVE HUMAN ENERGY Proportion of population involved in food production: N. America 2% 1 in 50 Brazil 20% 1 in 5 Mexico 25% 1 in 4 World wide 45% 1 in 2 Kenya 70% 2 in 3* *Mostly women and children. African women spend half of their waking hours working in the fields

43. PESTICIDES REDUCE WORLD HUNGER

44. ESTIMATED CONTRIBUTION OF CROP PROTECTION CHEMICALS TO WORLDWIDE PRODUCTION OF THE EIGHT PRINCIPAL FOOD AND CASH CROPS (1990 vs 1965) Oerke et. al., 1994 We harvest only 58% of the theoretical, world-wide yield