Carbonaceous matter and PBDEs on indoor/outdoor glass window surfaces in Guangzhou and Hong Kong, South China

Organic films, collected from indoor and outdoor window surfaces in Guangzhou and Hong Kong of South China, were analyzed to quantify their organic carbon (OC), elemental carbon (EC), and polybrominated diphenyl ethers (PBDEs) content. The highest concentrations of OC, EC, and BDE-209 were found in Guangzhou with values of 10 000 μg m−2, 2200 μg m−2, and 4000 ng m−2, respectively, and the highest concentration of Σ7PBDE (sum of BDE-28, -47, -99, -100, -153, -154 and -183) was found in Hong Kong with a value of 25 ng m−2. In most cases, the concentrations of PBDEs were higher in the exterior films than those in the interior films with BDE-209 as the predominant congener in both cities, suggesting that PBDEs mainly come from ambient environment, and deca-BDE accounts for major PBDE consumption. The growth rates of organic film on window surfaces were fast at the beginning, and reached a consistent level afterwards. The evolution rates ranged from 2.6 to 11 nm day−1 for “bulk film”, while from 0.06 to 0.92 nm day−1 for “pure film”. The concentrations of PBDEs on the window surfaces did not increase with the growth time, suggesting that the window surface may provide a good place for photo-degradation of PBDEs.