Dechlorane plus (DP) in indoor and outdoor air of an urban city in South China: Implications for sources and human inhalation exposure

<p>Dechlorane Plus (DP) is a chemical of emerging concern due to the restrictions on brominated flame retardant formulations. However, very little information is known about the occurrence of DP in indoor and outdoor air and its associated health risk to the exposed human population. In this study, we examined the concentrations and isomer profiles of DP in archived air samples collected from 14 homes, 6 offices, and 10 public microenvironments in Guangzhou, China in 2004–2005. The average (median) value of atmospheric ΣDP (sum of <i>anti-</i>DP and <i>syn-</i>DP) concentration in the three indoor air was 5.73 ± 5.33 (3.62) for offices, 8.08 ± 5.17 (6.87) for homes, and 57.27 ± 83.08 (32.58) pg/m³ for public microenvironments, respectively. ΣDP concentration was significantly higher in the public microenvironments than those in homes and offices. The arithmetic mean and median concentrations of ΣDP in outdoor air were 36.00 and 28.76 pg/m³, respectively. Spatially and temporally consistent indoor and outdoor samples comparison suggested that outdoor air might be a relevant source of DP for indoor air. Average <i>anti</i>-DP fractional abundance (<i>f</i>_anti = 0.65 ± 0.04) in all outdoor samples was similar to those reported in other studies and indistinguishable from that of the commercial mixture (<i>f</i>_anti = 0.65). In contrast, a relatively large variation of <i>f</i>_anti values was found in the indoor samples, suggesting a complex degradation process of DP existing in these microenvironments. The calculated average daily doses of ΣDP were in the range of 0.38–2.21 ng/day for people intake through air inhalation, which was in the same order of magnitude compared with other exposure pathways for the general publics.</p