Assessment by Personal Monitoring of Respirable Suspended Particles and Environmental Tobacco Smoke Exposure for Non-Smokers in Sydney, Australia

Abstract

In a study in Sydney, Australia, exposure to environmental tobacco smoke (ETS) particles and respirable suspended particles (RSP) for 319 self-reported non-smokers was assessed by personal monitoring. The subjects were separated into four distinct groups for investigation: Home, Work, Elsewhere, and 24-Hour, which were further sub-divided based on whether they lived or worked with smokers. Saliva samples for cotinine analysis were taken at the start and end of each monitoring session. Good correlations (R² > 0.86) were found between the three methods used in this study to assess the contribution of ETS particles to RSP from all sources. Annual exposure estimates for ETS particles and nicotine in smoking homes were greater than in smoking workplaces. Median annual exposure in smoking homes and workplaces equates to less than 4 cigarette equivalents per year (CE·y^–1). Exposures in non-smoking homes, non-smoking workplaces and away from the home and workplace were below the limit of quantification for most subjects. Based on the 90th percentile, the highest exposed subjects would potentially inhale no more than 15 CE·y^–1. Subjects living with smokers had greater ETS exposure while away from home and work compared to subjects living with non-smokers. This Elsewhere group were also exposed to the highest RSP concentrations. Questionnaire data indicated that subjects consider bars/restaurants to be the locations where they are exposed to most ETS in their daily lives. However, 62% of these subjects considered their exposure in these locations to be ‘none’ or ‘very low’ during the monitoring period. Saliva cotinine determinations would appear to be a good marker for evaluation of ETS exposure at 90th percentile levels. Out of 331 subjects recruited as non-smokers, 6 (1.8%) misreported their non-smoking status as demonstrated by their saliva cotinine level.