The toxic effects of combined exposure to toluene and m-xylene in animals. II. Blood toluene and m-xylene during single and combined exposure in rats.

The influence of combined exposure to m-xylene and toluene vapours at a concentration of 100 + 100 ppm on blood m-xylene concentration in rats was investigated. Within 6-7 hours of coexposure to m-xylene and toluene a significant increase in blood m-xylene concentration, in comparison to single exposure to m-xylene at concentration of 100 ppm, was observed. Study results may suggest that, reported earlier, the more than additive toxic effects of combined exposure to m-xylene and toluene in animals may result from its metabolic interaction.