Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Hong Kong using personal monitoring

Abstract

One hundred and ninety-four randomly selected nonsmoking subjects collected air samples in their breathing zone by wearing personal monitors for 24 h. The study was centered in Hong Kong, and comprised housewives in one group, primarily for assessing exposures in the home, and office workers in a second group to assess the contribution of the workplace to overall exposure. Samples collected were analysed for respirable suspended particles (RSP), nicotine, 3-ethenylpyridine, and environmental tobacco smoke (ETS) particles using ultraviolet absorbance (UVPM), fluorescence (FPM), and solanesol measurements (SolPM). Saliva cotinine analyses were also undertaken to confirm the nonsmoking status of the subjects and to investigate their correlation with ETS exposure measurements. Approximately 6% of the subjects in Hong Kong misclassified their nonsmoking status. Median time-weighted average (TWA) RSP concentrations varied from 43 to 54 μg m −3 with no significant differences detected between any of the groups investigated. Office workers who lived and worked with smokers were exposed to 2.6 μg m −3 ETS particles (SolPM) and 0.44 μg m −3 nicotine, based on median TWA concentrations. Median concentrations of ETS particles and nicotine were below the limits of quantification for housewives living with smokers and were not significantly different from those for housewives living with nonsmokers. It would therefore be unreliable in Hong Kong to use a smoking spouse as a marker for assessing health risks related to ETS exposure. The office workers in this study were significantly more exposed to ETS than housewives from either smoking or nonsmoking homes, and the workplace was estimated to contribute over 33% of the annual exposure to ETS particles and nicotine. Exposure estimates suggest that the most highly exposed office workers in this study receive between 11 and 50 cigarette equivalents per year, based upon upper decile levels for ETS particles and nicotine, respectively.