Environmental and biological monitoring of non-occupational exposure to 1,3-dichloropropene

Voluntary bystanders, simulating a situation of non-occupational exposure to Z- and E-1,3-dichloropropene (Z- and E-DCP), were exposed during field application of this nematocide in the Dutch flower-bulb culture. Environmental monitoring revealed that mean respiratory exposure concentrations of Z- and E-DCP varied from non-detectable levels to 1.12 mg/m3 8-h time-weighted average (TWA) for Z-DCP and to 0.91 mg/m3 8-h TWA for E-DCP. Biological monitoring was executed by determining urinary mercapturic acid metabolites of Z- and E-DCP according to a method recently validated in occupationally exposed applicators. A linear relationship between respiratory exposure to Z- and E-DCP and the urinary excretion of both mercapturic acids was observed in bystanders. Dermal uptake did not contribute significantly to the internal dose of Z- or E-DCP. The urinary mercapturic acid of Z-DCP was a more sensitive parameter for the detection of exposure than was respiratory air monitoring. In future studies it would be worthwhile to determine the extent of exposure of real bystanders to DCP on the basis of urinary mercapturic acid excretion.