Passive sampling of polybrominated diphenyl ethers in indoor and outdoor air in Shanghai, China: seasonal variations, sources, and inhalation exposure

Ninety-seven seasonal, passive indoor and outdoor air samples were collected in Shanghai to study polybrominated diphenyl ethers (ΣPBDEs, 16 congeners including BDE-209), their concentrations, composition profiles, seasonal variations, influencing factors, emission sources, and human inhalation exposure. In summer, median indoor concentrations of Σ ₁₅ PBDEs (excluding BDE-209) were 82 pg m⁻³ in offices and 30 pg m⁻³ in homes, ∼3 times the winter concentrations. The average summer concentration of 130 pg m⁻³ BDE-209 in homes was higher than that in offices (which was 90 pg m⁻³); in winter, home and office concentrations were similar (46 and 47 pg m⁻³, respectively). For outdoor air, the median concentration of Σ ₁₅ PBDEs in summer (12 pg m⁻³) was twice the winter concentration (6 pg m⁻³), while the summer median concentration of BDE-209 (398 pg m⁻³) was half the winter concentration (794 pg m⁻³). Higher concentrations of Σ ₁₅ PBDEs indoors compared with outdoors showed that the lower brominated BDEs found were mainly from indoor sources. Meanwhile, the much lower indoor concentration of BDE-209 compared with the outdoors showed that BDE-209 came mainly from outdoor sources. The data set also indicated that electric/electronic appliances were the main sources of indoor ΣPBDEs, and old appliances emitted more lower brominated BDEs, while industrial emissions should be the main source of the outdoor BDE-209. Median daily human exposures to Σ ₁₅ PBDEs and BDE-209 through inhalation were estimated to be 0.23 and 1.73 ng day⁻¹ in winter and 0.65 and 2.28 ng day⁻¹ in summer for adults. The human inhalation exposure to ΣPBDEs (3.44 ng day⁻¹ for adults and 1.33 ng day⁻¹ for toddlers) was comparable to that from eating contaminated fish for both toddlers and adults in Shanghai.