Human Health Effects: Cancer, Pesticides, Ergonomics

1. Human Health Effects:Cancer, Pesticides, Ergonomics Steven Kirkhorn, MD, MPH Immanuel St. Joseph’s Mayo Health System

2. Health issues • Increased • respiratory disease, arthritis, hearing loss, skin cancer • Migrant health clinic issues-dermatitis, enteric infectious diseases, respiratory, musculoskeletal, diabetes • Decreased • generally decreased mortality of all causes • tobacco and alcohol-related cancers • cardiovascular

3. Cancers of Concern • Increase in cancers that are increasing in other segments of the population also • Lip • Multiple myeloma • Childhood brain tumors • Prostate-weak association but significant

4. Inconsistent associations • NHL and phenoxyacetic acid herbicides • Breast/ovarian cancer and DDT/DDE • Prostate • Skin, melanoma • soft tissue sarcoma • Rectal, colon-increased PMRs in Iowa

5. No apparent associations • Leukemia and herbicides • Ovarian cancer and atrazine • Colon, soft tissue sarcoma, melanoma, rectal -Wisconsin study 1981-1990

6. Weaknesses of studies • Heterogeneity of studies, type of farming, geographic area • Limitations of exposure assessment • Multiple hazard exposures • pesticides, fertilizers, paints, solvents, • infectious microorganisms, endotoxin • dusts

7. Recommendations • Improved biomarkers • Increased use of biological monitoring • Improved homogeneity of studies • Standardization of endpoints • Focus upon populations with greater exposures to pesticides(fruit, vegetable, hot houses) • Present focus upon grain producers with average of 7-28 days/year of exposure

8. Pesticide-related illnesses • Annual decreases in pesticide fatalities, hospitalizations, and acute poisonings • Possible explanations • improved worker education -WPS • Improved technology-application/mixing • De-registration of more toxic agents • Better labeling and regulation

9. Common symptoms in pesticide applicator • 20-44% of applicators have exposures and symptoms • headache • skin irritation • respiratory and flu-like symptoms in animal applications

18. Neurologic complications: Acute pesticide exposure • Organophosphate induced delayed polyneuropathy (OPIDP) • Intermediate syndrome

19. Long-term neurologic effects of pesticides • Dose-response relationship suggested • Peripheral neuropathy • Slowed reaction time • Altered concentration • Non-specific CNS effects • ? Parkinson’s/motion disorders

20. Endocrine disrupter effects of pesticides • Female cancer concerns • Breast cancer • Ovarian cancer • Male reproductive effects

21. Endocrine disrupter effects of agricultural chemicals • No strong association with exposure and time to pregnancy • Reproductive effects • Increased male:female ratio(Garry et al 1996) • Not seen-Savitz et al 1997 • Infertility • Delayed time to conception • Spontaneous abortions, pre-term delivery

22. Pesticides and birth defects • Birth defects-limb reduction, oral-facial, cryptorchidism • Minor defects in ecological study of applicators in area with high use of fungicides and chlorphenoxy • More pronounced in infants conceived in spring

23. Pesticide issues-Monitoring Concerns • Lack of inter-laboratory standards • Variable results depending upon kit/lab • variable reporting units • Lack of consistent collection and storage techniques • Activation/inactivation of cholinesterase • Lack of reliable, inexpensive field monitoring

24. Recommendations • Improved causal linkages and dose-response relationships • Improved biomarkers • Improved consistency and accuracy of evaluation of acute and chronic cholinesterase depression

25. Recommendations • Improved reporting of pesticide-related illnesses • Nation-wide effort to improve and standardize medical surveillance of pesticide applicators and others with regular exposure to pesticides

26. Ergonomic issues • High incidence of musculoskeletal conditions- primarily back pain • California-Back 24%, upper back 19%, wrist 18% • Osorio et al, 1998

30. Chronic low back pain prevalence • Nursery workers back 46% of injuries • Chronic back pain-71% swine producers • Von Essen and McCurdy, 1998 • Back pain-26% of farmers and ranchers • Xiang et al, 1999 • Arthritis of hips and knees in dairy • May, 1998, Thelin 1991

31. Ergonomic issues • Increasing labor intensive agricultural work • Fruit harvesting, nurseries, small vegetable • Raised arms, pressure from straps of bags, repetitive forceful lifting, pinching, stooping, bending and twisting • Varied duties at multiple locations

32. Interventions • Handles on pots in nurseries-decrease pinch • Pallet trucks and tracks, automated washers • Loading ramps • Move to smaller pots • Improved fruit bags and straps, vests • Hinged boxes (Fulmer et al. 2000)

33. Recommendations • Thorough functional job assessments • Development of lighter, more flexible equipment, new tools, raising beds • Develop simple solutions that are inexpensive to produce and apply • Meyers et al. 1995, 1997

34. Other areas of concern • Zoonoses • Hepatitis E • Cryptosporodiosis • Coliforms • Sin nombre virus • Q fever • Dermatitis • Contact dermatitis • Under-reported

35. Emerging concerns of biotechnology • Probable improvement in hazard exposures • New exposures may occur

36. Bacillus thuringiensis (Bt) exposure issues • Positive skin prick tests, specific IgE antibodies, and nasal lavage cultures higher in high Bt-exposure workers. • No respiratory symptoms • Berstein et al. Immune responses in farm workers after exposure to Bt pesticides. • Environ Health Perspect 107: 575-82. (1999)

37. General recommendations • Improved medical surveillance • Improved reporting of illnesses, repetitive stress injuries • Establishment of dose-response relationships, biological monitoring • Better definition of study end-points • Continued support of prospective studies: The Agricultural Health, Keokuk, California Farmer Cohort Studies