Studies of Effects of Particle Size on The Toxicity of Insecticide Aerosols.

摘要

Inhalation toxicity values for aerosols of four insecticides (chlorpyrifos, malathion, naled and resmethrin) have been expressed as LD50 values in mg/kg body-weight. The inhalation LD50 was compared with the oral LD50 for four pesticide aerosols of mass median diameter 2.1 micrometer. By this method of comparison chlorpyrifos was slightly more toxic to rats by the inhalation than by the oral route but naled was about 21 times more toxic by the inhalation route. When the aerosol particle size was increased to mass median diameter 18 - 20 micrometer, the toxicity of naled was reduced by at least one-fourth. Malathion and resmethrin aerosols were insufficiently toxic to kill animals by practicable acute inhalation exposure. Significant plasma cholinesterase depression was observed when animals were exposed to sub-lethal doses of either chlorpyrifos or naled aerosols.