Pesticide Exposures and Other Agricultural Risk Factors for Leukemia Among Men in Iowa and Minnesota

Authors

Linda Morris Brown, Epidemiology and Biostatistics Program, National Cancer Institute, Bethesda, Maryland
Aaron Blair, Epidemiology and Biostatistics Program, National Cancer Institute, Bethesda, Maryland
Robert Gibson, University of Minnesota, Minneapolis, Minnesota
George D. Everett, Department of Internal Medicine, Orlando Regional Medical Center, Orlando, Florida
Kenneth P. Cantor, Epidemiology and Biostatistics Program, National Cancer Institute, Bethesda, Maryland
Leonard M. Schuman, University of Minnesota, Minneapolis, Minnesota
Leon F. Burmeister, University of Iowa, Iowa City, Iowa
Stephanie F. Van Lier, University of Iowa, Iowa City, Iowa
Fred Dick, University of Iowa, Iowa City, Iowa

Date of this Version

1990

Comments

Published in CANCER RESEARCH 50, 6585-6591, October 15, 1990.

Abstract

Mortality surveys and death certificate studies have suggested an association between leukemia and farming. To investigate whether exposure to carcinogens in an agricultural setting is related to risk of leukemia, the authors conducted a population-based case-control inter view study of 578 white men with leukemia and 1245 controls living in Iowa and Minnesota. Consistent with recent mortality studies, there were slight, but significant, elevations in risk for all leukemia (odds ratio (OR) 1.2) and chronic lymphocytic leukemia (OR 1.4) for farmers compared to nonfarmers. There were no significant associations with leukemia for exposure to specific fungicides, herbicides (including 2.4-1) and 2,4,5-T), or crop insecticides. However, significantly elevated risks for leukemia of ≥2.0 were seen for exposure to specific animal insecticides including the organophosphates crotoxyphos (OR 11.1), dichlorvos (OR 2.0), and famphur (OR 2.2) and the natural product pyrethrins (OR 3.7) and the chlorinated hydrocarbon methoxychlor (OR 2.2). There were also smaller, but significant, risks associated with exposure to nicotine (OR 1.6) and DDT (OR 1.3). This finding of elevated risks for insecticides used on animals deserves further evaluation.