Advances in the biological monitoring of mixed exposures: the case of toluene and xylene Abstract Previous studies have demonstrated that mixed solvent exposure is not only common, but also capable of exerting synergistic effects. Interpretation of biological monitoring data gathered in these settings requires the development of a conceptual framework. Blood and urine samples from healthy volunteers and from animals exposed to various concentrations of toluene and xylene, either alone or in combination, were analyzed.The study demonstrated the existence of a threshold for the production of interaction effects in volunteers exposed to xylene and toluene simultaneously. This threshold is slightly higher than the occupational exposure limits for these substances.This research project was the first study of human exposure to mixed solvents under strictly controlled conditions. It suggests that compliance with exposure standards may not provide adequate safety margins in cases of mixed exposure. These results should help health and safety specialists interpret biological monitoring data of mixed solvent exposure more accurately. Produced Under this Project Scientific Reports Interpretation of biological monitoring data for mixed exposure Research Summary: PR-129 Scientific Publications The determination of specific urinary thioethers derived from ethylene oxide and acrylonitrileGérin M., Tardif R., Brodeur J.Source : in International Agency for Research on Cancer, (1988 : Lyon), Methods for detecting DNA damaging agents in humans: Applications in cancer epidemiology and prevention, IARC Scientific Publication, no 89, Bartsch, H., K. Hemminki et I.K. O'Neill (ed.), p. 275Effect of simultaneous exposure to toluene and xylene on their respective biological exposure indices in humansTardif R., Laparé S., Plaa G. L., Brodeur J.Source : International Archives of Occupational and Environmental Health, vol. 63, no 4, 1991, p. 279-284Simultaneous high-performance liquid chromatographic analysis of hyppuric acid and ortho-, meta-, and para-methylhippuric acids in urineTardif R., Brodeur J., Plaa G. L.Source : Journal of Analytical Toxicology, vol. 13, 1989, p. 313-316Effect of various exposure scenarios on the biological monitoring of organic solvents in alveolar air: II. 1, 1, 1 - trichloroethane and trichloroethyleneLaparé S., Tardif R., Brodeur J.Source : International Archives of Occupational and Environmental Health, vol. 67, no 6, 1995, p. 374-375 Additional Information Type: Project Number: 0086-0190 Status: Completed Research Field: Chemical and Biological Hazard Prevention Team: Jules Brodeur (Université de Montréal)Gabriel Plaa (Université McGill)