Persistence of indoor permethrin and estimation of dermal and non-dietary exposure.

Pesticides applied indoors may persist longer than they would in outdoor environments, making people more vulnerable to the risk of exposure. Permethrin is a pyrethroid insecticide used in agricultural, residential, and public health sites, and is commonly detected in indoor environments. The objectives of this study were to evaluate the persistence of permethrin indoors and to estimate the levels of possible dermal and non-dietary exposure to this insecticide.

Pyrethroid concentrations and persistence following indoor application.

Residential indoor environments are potential sources of exposure to pyrethroids, which have low acute toxicity to humans but are allergenic and suspected endocrine disruptors. The present study evaluated the persistence of the pyrethroids cypermethrin and beta-cyfluthrin on indoor surfaces and in house dust. Cypermethrin and beta-cyfluthrin were applied and maintained on aluminum foils and in dust samples for 112 d under controlled conditions and for 12 mo in a test house; periodically, they were quantified by high-performance liquid chromatography.

Multiresidue screening methods for the determination of pesticides in tomatoes.

The possibility of applying thin layer chromatography (TLC) detection for the analysis of pesticide residues in tomatoes was investigated. Samples of tomatoes that have never been treated with pesticide were fortified with atrazine, carbaryl, carbofuran, chloroxuron, diuron, dimethoate, imazalil, oxamyl and methamidophos. The samples were extracted, cleaned-up by gel permeation chromatography and then applied on silica gel plates.