Dechlorane Plus in house dust from e-waste recycling and urban areas in South China: sources, degradation, and human exposure

During the present study, Dechlorane Plus (DP) was measured in house dust from e-waste recycling and from urban and rural areas of South China, with geometric mean concentrations of 604, 14.5, and 2.89 ng/g, respectively. Dechlorane Plus in house dust in the e-waste area originated from e-waste recycling activities, whereas household appliances served as a major source of DP in urban house dust. The isomer ratios (fanti) of DP in most dust samples from the e-waste area were significantly lower than those in the urban and rural dust samples and the common mixture. Several [-1Cl +H] and [-2Cl + 2H] dechloro-DPs were identified in house dust from the e-waste area, and an a-Cl11 DP was qualified with concentrations of <55.1 ng/g. Photolytic degradation experiments were conducted by exposing anti-DP, syn-DP, and common DP solutions to UV light. The slight difference in isomeric half-life derived by photodegradation, as well as the lower fanti values in the e-waste combusted residue, suggest a significant influence of isomer-specific thermal degradation of DP during e-waste burning on isomer composition in house dust in the e-waste area. The average estimated daily intakes (EDIs) of DP via house dust ranged from 0.06 to 30.2 ng/d for adults and 0.14 to 121 ng/d for toddlers in the studied area. The average EDIs of a-Cl11 DP for adults and toddlers in the e-waste area were 0.07 and 0.18 ng/d, respectively.

Authors: Wang, Jing; Tian, Mi; Chen, She-Jun; Zheng, Jing; Luo, Xiao-Jun; An, Tai-Cheng; Mai, Bi-Xian ;Full Source: Environmental Toxicology and Chemistry [online computer file] 2011, 30(9), 1965-1972 (Eng) ;