College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China; Engineering Research Center of Food Environment and Public Health, Beijing, 100081, China.
Environ Pollut. 2020 Feb;257:113622. doi: 10.1016/j.envpol.2019.113622. Epub 2019 Nov 14.
Samples of soil, air, and locally grown crops from around an old e-waste dismantling area (Fengjiang) and a new e-waste dismantling area (Binhai) in Taizhou were analyzed to investigate the behavior of polychlorinated biphenyls (PCBs) released during e-waste dismantling in the soil-crop-atmosphere system. The results indicated that PCB pollution is still widespread in the study area. The PCB concentrations were clearly higher in soil from FJ than in soil from BH, and the concentrations in the functional zones decreased strongly in the order industry park > residential area > farmland. Historical and current emissions during e-waste dismantling processes are probably the main sources of PCBs to soil because PCB production and use are banned. The long half-lives of PCBs have caused the target congener concentrations in soil not to decrease markedly over 10 years. The "halo effect" may have caused PCBs in soil in the heavily polluted FJ area to diffuse into the surrounding area. Soil-air exchange of PCBs in heavily contaminated FJ area may supply PCBs to air because the temperatures in Taizhou are often high. PCBs can accumulate in crops through various pathways. Less-chlorinated PCBs (mainly including Tri-PCBs) can enter crops by root uptake and translocated to the aerial tissues, and more-chlorinated PCBs (including Penta-PCBs and Hexa-PCBs) at high concentrations in soil can enter underground crop tissues through passive transport. More-chlorinated PCBs in underground tissues cannot be transferred to aboveground tissues of tall crops but may be transferred to aboveground tissues of short crops through the root-to-stem pathway and through soil dust being transferred to aboveground external surfaces.
对来自台州一个旧电子废物拆解区（枫江）和一个新电子废物拆解区（滨海）周围的土壤、空气和当地种植的作物样本进行了分析，以研究在电子废物拆解过程中释放到土壤-作物-大气系统中的多氯联苯（PCBs）的行为。结果表明，该研究区域仍广泛存在 PCB 污染。FJ 地区土壤中的 PCB 浓度明显高于 BH 地区，功能区的浓度按工业园>居民区>农田的顺序强烈下降。历史和当前电子废物拆解过程中的排放可能是土壤中 PCBs 的主要来源，因为 PCB 的生产和使用已被禁止。PCBs 的长半衰期导致土壤中目标同系物浓度在 10 年内没有明显下降。“晕圈效应”可能导致污染严重的 FJ 地区土壤中的 PCBs 扩散到周围地区。由于台州气温经常较高，FJ 地区污染严重的土壤与空气之间的 PCBs 交换可能会向大气中提供 PCBs。PCBs 可以通过多种途径在作物中积累。低氯代 PCBs（主要包括三氯代 PCBs）可以通过根系吸收并转移到气生组织进入作物，而土壤中高浓度的多氯代 PCBs（包括五氯代 PCBs 和六氯代 PCBs）可以通过被动运输进入地下作物组织。地下组织中的高氯代 PCBs 不能转移到高大作物的地上组织，但可能通过根到茎的途径和土壤灰尘转移到地上外部表面转移到地上短作物组织中。
