The present report examines the in vitro genotoxicity (micronucleus assay) of herbicides and adjuvants and reports on an in vivo human study on potential endocrine effects of pesticides, including herbicides. Adjuvants are used in conjunction with 2,4-dichlorophenoxy acetic acid (2,4-D) and other herbicides. Earlier pesticide applier survey results (n = 709) show that 59% of the applicators used adjuvants, and the majority of this group used paraffinic oils and/or surfactant mixtures. As a beginning effort to explore the role of adjuvants and herbicides in hormonally based reproductive effects, a prospective, controlled study was performed to analyze blood specimens from three different exposure groups (applicators using herbicides only; applicators using both herbicides and insecticides; and applicators using fumigants in addition to herbicides and insecticides; and a control group composed of other agricultural workers including organic farmers). The applicators and controls were age- and smoking-matched. Study subjects (n = 78) were tested before, during, and after completion of pesticide application season for the effects of pesticide products on hormone levels in the bloodstream. Of the applicator exposure groups examined, only the herbicide group showed significant endocrinologic differences from controls. Free testosterone levels were significantly elevated in post-season measurements (p = 0.032), and follicle-stimulating hormone (FSH) was significantly decreased at the height of the season (p = 0.016) and in the post-season (p = 0.010) as compared to controls. These endocrinologic findings are discussed in terms of their possible relationship to potential endocrine effects of herbicides, herbicide contaminants, and adjuvants. In vitro genotoxicity examination compared four different commercially available surfactant mixtures with 12 different commercial herbicide products, including six different chlorophenoxy herbicides. Only one herbicide yielded a significant dose-response curve. All four adjuvants showed positive dose-response effects. These preliminary data suggest that adjuvants are not inert but are toxicologically active components added to herbicide mixtures. Whether adjuvant toxicant effects are additive or are independent of herbicide effects is poorly understood.

We surveyed 1,000 randomly selected state-licensed pesticide appliers to improve our understanding of pesticide use and its potential health effects. Participants were stratified by pesticide class (herbicides, insecticides, fungicides, fumigants) to determine potential differences in health characteristics among different pesticide groups. A subset of 60 applicators, divided by pesticide class used, were studied for exposure-related cholinesterase (ChE) depression. ChE depression in excess of 20% was most frequent in fumigant applicators who did enclosed-space application, in addition to other pesticide application procedures (p < .05). Survey data demonstrated that the prevalence of all common chronic diseases considered together was significantly increased (p = .015) in fumigant appliers, compared with all other pesticide use groups. The frequency of chronic lung disease was also significantly increased in the fumigant applier group (p = .027). Curiously, two cases of a rare hematopoietic neoplasm--hairy cell leukemia--were identified in our study group (annual incidence 0.67/100,000 in Minnesota). Whether there is an association between this unique tumor and agricultural work is uncertain, and further study is needed in this regard.