Urinary protein markers in pesticide applicators during a chlorinated hydrocarbon exposure

A previous study of 16 pesticide applicators showed that N-acetylglucosaminidase (NAG) excretion during exposure to the soil nematocide, 1,3-dichloropropene (DCP), was correlated with DCP dose and the excretion of its major metabolite, N-acetyl-S-(cis-3-chloroprop-2-enyl)-cysteine (3CNAC). Using the same urine samples, two other proteins were measured: low concentrations of albumin ("microalbuminuria," ALB) and retinol-binding protein (RBP). For each worker there were five consecutive urine collection intervals (6-8 hr each): overnight prior to exposure, morning work shift, afternoon work shift, evening after work, and overnight. Paired comparisons of each interval to baseline (first interval) for each protein excretion (creatinine corrected) did not reveal significant increases. However, amounts of renal proteins per interval, in contrast to creatinine-corrected concentrations, were more strongly correlated with each other and with 3CNAC concentrations within samples. Clear dichotomous differences in urinary protein excretion were seen for high versus low exposure (< or > 1.5 mg 3CNAC excretion/day) for NAG and RBP, but not for ALB. Based on earlier findings of a slight elevation of NAG and the minimal changes reported herein for RBP, the possible effects of short-term workplace exposure to DCP on renal protein excretion appear to be mild.