Abstract
Domestic human exposure to insecticides was studied by the analysis of insecticide concentrations in vacuumed household dust as an indicator of indoor pollution. Here we describe the residue levels of six kinds of insecticides in 32 household dust samples collected during the year 2001 in Osaka district.
Insecticides in dust samples were extracted with acetone and hexane under ultrasonic waves. The extract after filtration was defatted by liquid-liquid partition with hexane/acetonitrile. Cleanup of insecticides in the defatted extract was conducted using a graphite carbon column followed by a silica gel 40 mini column. Quantitative analyses of the insecticides were performed with GC by electron-capture detection or flame photometric detection using a capillary column.
Chlorpyrifos was detected in 27 out of 32 samples analyzed at a level of <0.01 to 20.4μg/g. Higher concentrations of chlorpyrifos residue were detected in the household dust collected from houses treated with chlorpyrifos for termite control. The incidence (7/32) and levels (max: 0.15μg/g) of diazinon in household dust were very low. Fenitrothion was detected in 23 out of 32 samples (max: 0.38μg/g, median: 0.02μg/g) tested. Residue levels of permethrin (max: 71.6μg/g, mean: 5.3μg/g, median: 0.6μg/g) detected in dust samples were the highest among 6 kinds of insecticides analyzed. S-421 (2, 3, 3, 3, 2', 3', 3', 3'-octachlorodipropyl ether) was detected in all 32 samples at a level of 0.03 to 6.19μg/g, and ρ-dichlorobenzene was also detected in all samples, with levels ranging from 0.02 to 2.07μg/g.
