Human Health Effects:Cancer, Pesticides, Ergonomics

Steven Kirkhorn, MD, MPHImmanuel St. Joseph’sMayo Health System

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

Cancers of Concern

Increase in cancers that are increasing in other segments of the population also

LipMultiple myelomaChildhood brain tumorsProstate-weak association but

significant

Inconsistent associations

NHL and phenoxyacetic acid herbicides

Breast/ovarian cancer and DDT/DDEProstateSkin, melanomasoft tissue sarcomaRectal, colon-increased PMRs in Iowa

No apparent associations

Leukemia and herbicidesOvarian cancer and atrazineColon, soft tissue sarcoma,

melanoma, rectal -Wisconsin study 1981-1990

Weaknesses of studies

Heterogeneity of studies, type of farming, geographic area

Limitations of exposure assessmentMultiple hazard exposures

pesticides, fertilizers, paints, solvents, infectious microorganisms, endotoxin dusts

Recommendations

Improved biomarkersIncreased use of biological monitoringImproved homogeneity of studiesStandardization of endpointsFocus 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

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

Common symptoms in pesticide applicator

20-44% of applicators have exposures and symptoms headache skin irritation respiratory and flu-like symptoms in

animal applications

Neurologic complications: Acute pesticide exposure

Organophosphate induced delayed polyneuropathy (OPIDP)

Intermediate syndrome

Long-term neurologic effects of pesticides

Dose-response relationship suggested

Peripheral neuropathySlowed reaction timeAltered concentrationNon-specific CNS effects? Parkinson’s/motion disorders

Endocrine disrupter effects of pesticides

Female cancer concerns Breast cancer Ovarian cancer

Male reproductive effects

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

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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

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

Recommendations

Improved causal linkages and dose-response relationships

Improved biomarkersImproved consistency and accuracy

of evaluation of acute and chronic cholinesterase depression

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

Ergonomic issues

High incidence of musculoskeletal conditions- primarily back pain

California-Back 24%, upper back 19%, wrist 18%

Osorio et al, 1998

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 ranchersXiang et al, 1999

Arthritis of hips and knees in dairyMay, 1998, Thelin 1991

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

Interventions

Handles on pots in nurseries-decrease pinch

Pallet trucks and tracks, automated washers

Loading rampsMove to smaller potsImproved fruit bags and straps, vests

Hinged boxes (Fulmer et al. 2000)

Recommendations

Thorough functional job assessmentsDevelopment of lighter, more flexible

equipment, new tools, raising bedsDevelop simple solutions that are

inexpensive to produce and applyMeyers et al. 1995, 1997

Other areas of concern

Zoonoses Hepatitis E Cryptosporodiosis Coliforms Sin nombre virus Q fever

Dermatitis Contact dermatitis Under-reported

Emerging concerns of biotechnology

Probable improvement in hazard exposures

New exposures may occur

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)

General recommendations

Improved medical surveillanceImproved reporting of illnesses, repetitive

stress injuriesEstablishment of dose-response

relationships, biological monitoringBetter definition of study end-pointsContinued support of prospective studies:

The Agricultural Health, Keokuk, California Farmer Cohort Studies