DETERMINANTS OF DISABILITY IN ILLNESSES RELATED TO AGRICULTURAL USE OF ORGANOPHOSPHATES (OPS) IN CALIFORNIA

Organophosphate (OP)-related illness data reported to the Worker Healt h and Safety Branch (WH&S) at the California Department of Food and Ag riculture (CDFA, now Cal-EPA) in the years 1984-1988 were examined. Ei ght hundred and seventy-eight cases with systemic illness and 199 case s of skin disease or eye injury were identified. Systemic cases were d ivided into two outcome groups: (1) ''severe,'' disability and/or hosp italization days (n = 361), and (2) ''mild,'' no disability or hospita lization days (n = 372). For the remainder (n = 145) or 16.5% of the c ases, illness severity could not be determined. Using multiple logisti c regression, independent predictors of ''severe'' illness were identi fied among the systemic cases. Workers coming in contact with OP resid ue on commodities or in the field (''exposed to residue'' or ER) (OR = 4.6, 95% CI = 3.03-7.07) and mixer/loaders/applicators (MLA) (OR = 4. 1, 95% CI = 2.72-6.07) were at significantly increased risk of severe illness when compared with cases exposed to OP application drift. Case s with a Spanish surname were also at increased risk of severe illness (OR = 1.8, 95% CI = 1.25-2.73). Increased numbers of OPs per exposure were also associated with severe illness (p < 0.001). Among cases who were exposed to only one OP, severe systemic cases were more likely t han mild systemic cases to be associated with exposure to diethyl than dimethyl compounds (OR = 1.6, 95% CI = 1.09-2.38). Severe systemic ca ses were also more likely than severe skin/eye cases to be associated with exposure to OPs with high toxicity (OR = 5.5, 95% CI = 2.42-12.60 ) and with exposure to diethyl groups (OR = 4.8, 95% CI = 1.90-12.00). These findings suggest that reducing exposure to OP residues, to OPs with diethyl groups, and to multiple OPs, and exposure during mixer/lo ader/ applicator activities would reduce the risk of OP-related illnes s. (C) 1995 Wiley-Liss, Inc.