Carbofuran is a
carbamate insecticide registered for use on a variety of food crops including corn, alfalfa, rice, and tobacco. An estimated 5 million pounds of
carbofuran is used annually in the United States, and 45% of urban African-American women have detectable levels of
carbofuran in their plasma. Nitrosated
carbofuran has demonstrated mutagenic properties. We examined exposure to
carbofuran and several
tumor sites among 49,877 licensed
pesticide applicators from Iowa and North Carolina enrolled in the Agricultural Health Study. We obtained information regarding years of use, frequency of use in an average year, and when use began for 22 pesticides using self-administered questionnaires. Poisson regression was used to calculate rate ratios (RR) and 95% confidence intervals (CIs) adjusting for potential confounders.
Lung cancer risk was 3-fold higher for those with > 109 days of lifetime exposure to
carbofuran (RR = 3.05; 95% CI, 0.94-9.87) compared with those with < 9 lifetime exposure days, with a significant dose-response trend for both days of use per year and total years of use. However,
carbofuran use was not associated with
lung cancer risk when nonexposed persons were used as the referent. In addition,
carbofuran exposure was not associated with any other
cancer site examined. Although
carbamate pesticides are suspected human
carcinogens, these results should be interpreted cautiously because there was no a priori hypothesis specifically linking
carbofuran to
lung cancer.