[Biological monitoring of workers exposed to nitrofen and experimental study on its skin permeability]

Eleven packing workers in a nitrofen manufacturer were selected in a three consecutive day field study, Skin contamination, urine excretion, and air concentration of nitrofen before and after workshift were monitored with GC-ECD method. Results showed air nitrofen concentrations in the workplace were extremely high, ranging from 5.12 to 21.60 mg/m3 (TWA). The hand and forehead in workers, who handled wettable nitrofen powder with bare hands, were contaminated by nitrofen with levels of 5.80 and 1.15 micrograms/cm2, respectively. Nitrofen excretion in urine increased after workshift and reached the highest in 10 hours, with a half excretion time of 13 hours. Permeability study with a flow-through diffusion cell in vitro showed nitrofen could easily penetrate human skin in different location of the body, and the permeability in forearm skin was stronger than that in thigh, and much more than that in abdomen skin. Nitrofen amount penetrated increased greatly as the skin barrier was damaged. Both the skin and respiratory absorption could be the important routes for nitrofen uptake. It was imperative to protect the skin from contamination while to strengthen respiratory protection. Results also suggested nitrofen level in urine could be used to indicate the body uptake through different routes.