Distribution and possible sources of PBDEs in indoor dust in Guangzhou City.

Dust samples were collected randomly from forty-six houses, twelve offices, seventeen outdoor sites, two televisions and two computers in Guangzhou City to determine the concentrations, distribution and possible sources of PBDEs in indoor dust. Concentration of ∑10PBDEs (sum of BDE28, 47, 66, 85, 99, 100, 153, 154, 183, and 209) varied from 564.3 to 9654ng/g (median 2686ng/g, mean 3407ng/g) for house dust, and from 1737 to 4408 ng/g (median: 3133ng/g; mean: 3179ng/g) for office dust. BDE209 was the dominant congener detected, with an average contribution of 97.4% and 99.0% to Σ10PBDEs for house dust and office dust, respectively, whereas BDE47, 99 and 183 were the most abundant congeners of ∑9PBDEs (BDE209 excluded). ∑10PBDEs concentration in indoor dust was higher than that in the outdoor dust, indicating possible indoor emission sources for PBDEs indoors. The predominant commercial products source for PBDEs in indoor dust was Deca-BDE formulations, followed by Penta-BDE, and the contribution of Octa-BDE was minimal.