Prevention of exposure to mutagenic fumes produced by hot cooking oil in Taiwanese kitchens.

We evaluated the mutagens in fumes produced by heating three different cooking oils used in Taiwan to temperatures of 100 degrees C, 200 degrees C, and 300 degrees C, and constructed models to study the efficacy of fume extractors used commonly by Taiwanese women. Particulates of volatile emissions from lard (at 200 degrees C and 300 degrees C) and soybean oil (at 300 degrees C) were found to be mutagenic in the Salmonella/microsomal test with S9 mix, indicating that exposure of Taiwanese women to cooking oil fumes may be an important risk factor in the etiology of their lung cancer. Mutagenicity of lard and soybean oil fumes collected at 300 degrees C was obtained when a commonly used fume extractor was located at a usual distance of 70 cm above the oil surface, whereas the fume samples were not, or weakly, mutagenic in the Salmonella/ microsomal assay when the distance between fume extractor and oil surface was 60 cm or less. Reduction in mutagenicity was on average 1.2 +/- 0.5 revertants/cm (the percent reduction in mutagenicity was 46%), pointing to a possible cooking practice involving significant reductions in exposure to harmful oil fumes and, consequently, a decreased risk of lung cancer in Taiwanese housewives.