A PRELIMINARY-STUDY OF IMMUNOLOGICAL AND HEMATOLOGIC PROFILES OF PERIPHERAL-BLOOD FROM NEBRASKA FARMERS WHO APPLY PESTICIDES TO THEIR FIELDS

Objective: Laboratory studies have documented a wide range of pesticid e-induced changes in the hematopoietic and lymphoreticular systems. So me of these are expressed as altered serum values, blood cell counts, and leucocyte functions. The goal of the present study was to determin e whether these alterations were evident in peripheral blood of Nebras ka farmers who applied pesticides to their fields. Methods: An invitat ion to participate was mailed to 100 residents (70 farmers; 30 control s) of Butler County, Nebraska. All respondents (51 farmers and 21 cont rols) were enrolled and surveyed by written questionnaire for health s tatus and pesticide use. Our analysis included 45 farmers and 18 contr ols. The farmers were divided into a high (n = 23) and a low (n = 22) pesticide use group. Statistical correlations of ten blood values with both pesticide use and age were evaluated, since pesticide use correl ated with age. Results: Four of the ten blood values correlated with p esticide use and age (Spearman Rho). In a multiple regression model, p esticide use (not age) proved to be a predictor of red blood cell coun t and hematocrit. In the same model, pesticide use was not a predictor of mean red cell volume or candida antigen-induced T-lymphocyte proli feration. Serum complement activity did not correlate with pesticide u se among the farmers (n = 45) but was significantly reduced (ANOVA) in the high pesticide use group, compared to controls. Conclusions: A pr eliminary study of blood values in a small cohort of Nebraska farmers found no pesticide-associated effects on 1) leucocyte count, 2) antige n- and mitogen-stimulated T-cell proliferation, 3) mitogen-stimulated B-cell proliferation, and 4) concentrations of serum IgG and IgM. The study found small but statistically significant pesticide-associated e ffects on red blood cells and serum complement.