Key Words Air quality Nicotine

Cigarette equivalents Personal monitoring The study was centred in Beijing, People’s Republic of China, 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. Two hundred and fifty-three randomly selected non-smok-ing subjects collected air samples near to their breathing zone by wearing per-sonal monitors for 24 h. Samples collected were analysed for respirable sus-pended particles (RSP), nicotine, 3-ethenylpyridine and environmental tobac-co smoke (ETS) particles using ultraviolet absorbing particulate matter (UVPM), fluorescing particulate matter (FPM) and solanesol-related particu-late matter (SolPM) measurements. Saliva cotinine analyses were also under-taken to confirm the non-smoking status of the subjects, and a misclassifica-tion rate of between 3.4 and 3.8 % was estimated. RSP levels were the highes