电子垃圾拆解区及其周边大气中得克隆的污染和呼吸暴露研究

添加型高氯代阻燃剂得克隆(dechlorane plus,DP)因为在环境中表现出普遍存在性、持久性、生物富集性、长距离迁移性和毒性,近年来迅速引起各国环境科学家的关注和重视。DP广泛应用于电线电缆等电子产品塑料中,粗放式电子垃圾拆解活动已被证实是环境中DP的重要污染来源之一。为探讨电子垃圾拆解区及其周边地区大气中DP的污染特征、呼吸暴露剂量和影响因素,对典型电子垃圾拆解区贵屿(GY)及其周边地区陈店(CD)和对照市区(广州市天河区,TH)进行大气采样和DP分析,并运用Monte Carlo模拟计算其日呼吸摄入剂量,同时对暴露参数进行了灵敏度分析。结果表明:受当地粗放式电子垃圾拆解活动的影响,GY大气中的DP平均浓度(范围)高达(1 119±1 021)pg·m-3(410~3 381 pg·m-3),远高于CD(52.2±30.2,20.9~102 pg·m-3)和TH(5.04±2.73,0.967~9.43 pg·m-3);受GY大气污染扩散迁移的影响,CD大气中的DP浓度也显著高于TH(t-test,P=0.006);GY大气中反式DP的比例(fanti)与DP商业品(fanti=0.70)无显著差异(t-test,P=0.08),这与其存在本地排放源一致,而TH大气中的fanti显著低于DP商业品(t-test,P=0.000);3个地区居民的DP日均呼吸摄入剂量(pg·kg-1·d-1)分别为:GY成人1 888,儿童1 912;CD成人60.9,儿童62.8;TH成人5.16,儿童5.25;呼吸速率是DP日呼吸摄入剂量的主要贡献因子,其次为大气中的DP浓度和体重,体重对于儿童的影响远高于成人。上述研究结果表明GY及其周边地区居民均处于较高DP呼吸暴露风险中。

Occurrence and Inhalation Exposure of Dechlorane Plus in the Atmosphere around E-waste Recycling Area and Its Surrounding Area

Dechlorane plus (DP), a highly chlorinated additive flame-retardant used for about 50 years, recently attracted much attention from scientists worldwide due to its ubiquitousness, persistence, bioaccumulativity, long-range transportability and toxicity in environment. DP is mainly employed in commercial polymer products including coating electrical wires and cables, connectors in computer and televisions, and plastic roofing materials for building. Primitive electronic waste (e-waste) recycling activities have been proved as an important source of DP in environment. In this study, air samples were collected from Guiyu (GY), a typical e-waste recycling area, Chendian (CD), a neighboring town of GY, and Tianhe District (TH), a contrast urban area, and analyzed for DP with the aim to investigate the pollution, inhalation exposure dose and influential factors of DP in these areas. The results showed that the mean DP concentration±SD (range) in air of GY was up to 1 119±1 021 (410~3 381) pg.m-3, much higher than those of CD (52.2±30.2, 20.9~102 pg.m-3) and TH (5.04±2.73, 0.967~9.43 pg.m-3). This was attributed to the local e-waste recycling activities in GY, e.g. dismantling, burning, incineration, etc. Although there were neither e-waste recycling industry nor DP production or application in CD, the atmospheric DP levels in CD were significantly higher than in the contrast urban area TH (t-test, P=0.006). This was due to the long-rang transport of the heavily polluted air from GY. The fractions of anti-DP (fanti) in GY showed no significant difference from that of the commercial DP product (fanti =0.70, t-test, P=0.08), in accordance with its local e-waste recycling emission source. While significant difference was found between the fantis of TH and technical DP product (t-test, P=0.000). The daily inhalation dose (DID) of DP and its influential factors were estimated with Monte Carlo simulation for local residents. The average DIDs of DP were 1 888 and 1 912 pg?kg^-1?d-1 for adults and children in GY, 60.9 and 62.8 pg?kg^-1?d-1 for adults and children in CD, and 5.16 and 5.25 pg?kg^-1?d-1 for adults and children in TH, respectively. The sensitivity analysis results suggest that inhalation rate was the predominant contributor to the DID of DP, followed by the atmospheric concentration of DP and body weight (BW). Comparatively, the DIDs of children were more affected by BW than those of adults. On the whole, residents in GY and its surrounding areas were in high DP inhalation exposure risk.