Personal exposure and source characteristics of carbonyl compounds and BTEXs within homes in Beijing, China

Exposure to indoor chemical air pollutants is expected to increase potentially the chance of developing cancer. Ambient levels of carbonyl (formaldehyde, acetaldehyde, acrolein and acetone) and BTEXs (benzene, toluene and xylenes) compounds were monitored at 210 residential homes in Xicheng district, Beijing, during the period of November–December 2009. The indoor concentrations of formaldehyde, acetaldehyde, acrolein, acetone, benzene, toluene and xylenes were in the range of 0.2–213.4 μg m−3, 0.7–140.9 μg m−3, 0.1–25.2 μg m−3, 0.3–102.1 μg m−3, 1.0–47.5 μg m−3, 1.3–552.6 μg m−3 and 0.2–150.6 μg m−3, respectively. Average concentrations of formaldehyde, acetaldehyde, acrolein, acetone, benzene, toluene and xylenes were 21.8 μg m−3, 16.3 μg m−3, 2.8 μg m−3, 10.7 μg m−3, 9.0 μg m−3, 32.1 μg m−3 and 12.3 μg m−3, respectively. The individual samples were mostly lower than the Chinese guideline values except formaldehyde and toluene, which showed higher values in 91 and 29 samples. Statistical analysis and I/O (indoor concentration/outdoor concentration) ratio results showed that the main sources of formaldehyde, acetaldehyde, benzene and toluene at homes with renovation age <5 years were organic solvents used in adhesives and decoration materials. Meanwhile, outdoor emission factors may have an impact on acetone, acrolein and xylenes concentrations of indoor air at different homes, and on formaldehyde, acetaldehyde, benzene and toluene concentrations of indoor air at homes with renovation age >5 years. Our results also showed that higher cancer risks for human exposure to formaldehyde, acetaldehyde and benzene than previous studies in Guangzhou and Hangzhou, China with one exception.