Contribution of Secondhand Smoke and Multiple Outdoor Sources in ?Residential Indoor Polycyclic Aromatic Hydrocarbon Level

摘要

Objectives: Extent to which multiple sources contribute to indoor concentrations of individual PAH species is little known within intensive coal-burning regions. Here, we examined the contribution of indoor and outdoor sources on individual species of the airborne PAHs. Methods:lndoor and outdoor concentration of nine common PAHs - benz[a]anthracene, chrysene/isochrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene and pyrene were monitored in 75 homes for 48 hour period across a two-year period in Krakow, Poland. Due to no known indoor sources for pyrene, we used pyrene as a tracer for infiltration of outdoor air. Indoor concentrations of eight PAHs were partitioned to indoor and outdoor source contributions. Results: Relative importance of season-related outdoor sources and secondhand smoke differed for the nine PAH species. In homes reporting ＞5 hours of daily secondhand smoke, median concentrations of benzo[g,h,i]perylene, benzo[a]pyrene, D[a,h]A, and indeno(1,2,3-c,d)pyrene were ＞ 1.7 times higher than outdoors, while median I/O ratios for benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and chrysene were ＜ 1.5. Using pyrene as a tracer, the outdoor sources contributed to indoor air concentration of benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and chrysene more substantially (i.e. 2- to 7-times) than did the indoor sources. In contrast, in homes reporting cigarette smoking, the tobacco and outdoor related sources contributed equally for benzo[g,h,i]perylene, benzo[a]pyrene, D[a,h]A, and indeno(1,2,3-c,d)pyrene. Conclusion:lndoor concentration of benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and chrysene were predominantly determined by infiltrated outdoor PAHs. In contrast, benzo[g,h,i]perylene, benzo[a]pyrene, D[a,h]A, and indeno(1,2,3-c,d)pyrene - species of highest carcinogenic and mutagenic potencies - were contributed not only by the outdoor sources, but also by secondhand smoke.