Personal exposures and microenvironmental concentrations of benzene were measured in the residential indoor, residential outdoor and workplace environments for 201 participants in Helsinki, Finland, as a component of the EXPOLIS-Helsinki study. Median benzene personal exposures were 2.47 (arithmetic standard deviation (ASD) = 1.62) mug m(-3) for non-smokers, 2.89 (ASD = 3.26) mug m(-3) for those exposed to environmental tobacco smoke in any microenvironment and 3.08 (ASD = 10.04) mug m(-3) for active smokers. Median residential indoor benzene concentrations were 3.14(ASD = 1.51) mug m(-3) and 1.87 (ASD = 1.93) mug m(-3) for environments with and without tobacco smoke; respectively. Median residential outdoor benzene concentrations were 1.51 (ASD = 1.1 1) mug m(-3) and median workplace benzene concentrations were 3.58 (ASD = 1.96) mug m(-3) and 2.13 (ASD = 1.49) mug m(-3) for environments with and without tobacco smoke, respectively. Multiple step-wise regression identified indoor benzene concentrations as the strongest predictor for personal benzene exposures of those not exposed to tobacco smoke, followed sequentially by time spent in a car, time in the indoor environment, indoor workplace concentrations and time in the home workshop. Relationships between indoor and outdoor microenvironment concentrations and personal exposures showed considerable variation between seasons, due to differences in ventilation patterns of homes in these northern latitudes. Automobile use-related activities were significantly associated with elevated benzene levels in personal and indoor measurements when tobacco smoke was not present, which demonstrates the importance of personal measurements in the assessment of exposure to benzene. (C) 2001 Elsevier Science Ltd. All rights reserved.
