[Polybrominated Diphenyl Ether in E-waste Dismantling Sites in Taizhou City, Zhejiang Province: Concentration, Distribution, and Migration Trend].

The concentration of polybrominated biphenyl ethers (PBDEs) in surface soil and atmosphere of e-waste dismantling sites in Taizhou city, Zhejiang Province was determined. The concentration ranges of ∑12PBDEs in surface soil of e-waste dismantling site, farmland, and resident areas in Fengjiang Town (FJ) and Binhai Town (BH) were 21.8-1310 ng ·g-1 and 6.19-220 ng ·g-1, respectively. No significant difference was observed in the distribution of PBDEs between the FJ and BH soil. The concentration range of ∑12PBDEs in the atmosphere of FJ and BH were 262-3240 pg ·m-3 and 840-2990 pg ·m-3, respectively. The median levels of PBDEs in the atmosphere of FJ and BH were 1410 pg ·m-3 and 840 pg ·m-3 in winter and 1590 pg ·m-3 and 1960 pg ·m-3 in summer, respectively. However, a significant difference was observed in the distribution of 11 PBDE congeners, except BDE-209, during winter and summer seasons. The migration trend analysis showed the differences between the soil and air of FJ and BH. The main migration trend of 3-5-BDEs was the volatilization from soil to atmosphere, and the increase in temperature promoted the volatilization of these PBDEs from soil to atmosphere in FJ. This indicated that the PBDEs in soil had become a major source of pollution emission and suggested that soil remediation should be carried out at the e-waste dismantling site and parts of farmland in FJ. Contrary to FJ, atmospheric deposition was the major migration trend of PBDEs and the soil was the main sink of PBDEs in BH. This indicated that e-waste dismantling site in BH could be a new source of PBDEs emission in this area.

Polychlorinated biphenyls in the soil-crop-atmosphere system in e-waste dismantling areas in Taizhou: Concentrations, congener profiles, uptake, and translocation.

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.

[Distribution of 16 Polycyclic Aromatic Hydrocarbons in Dianchi Lake Surface Sediments After the Integrated Water Environment Control Project].

The external pollution of Dianchi Lake has been effectively controlled with the implementation of the integrated water environment control project. However, further attention should be paid to endogenous pollutants, such as surface sediments. To investigate the distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Dianchi Lake, PAH concentrations in 19 surface sediment samples (collected in December 2016) were quantitatively measured by gas chromatography-mass spectrometry (GC-MS). The spatial and temporal distribution, sources, and ecological risks were also analyzed. The concentration of total PAHs (TPAHs) in the Dianchi Lake surface sediments varied in the range of 92.31-1546.78 ng·g-1 with an average of 496.30 ng·g-1. The average concentration of TPAHs in the surface sediments from Caohai (932.37 ng·g-1) was much greater than that from Waihai (380.02 ng·g-1). With the implement of the integrated water environment control project, the concentration of TPAHs in the surface sediments from Dianchi Lake was significantly lower than those detected in 2012, and was already relatively low level among other key waterbodies in China. The PAH with the highest concentration was fluoranthene (80.65 ng·g-1) and the substance with the highest toxic equivalent quantity (TEQ) was dibenz[a, h] anthracene (42.97 ng·g-1). The PAHs were mainly composed of 4 ring and 5-6 ring compounds (with the concentration ratio of 40.38% and 40.22%, respectively), which indicated that the proportions of middle-ring and high-ring compounds were generally consistent. The results of the molecular diagnostic ratio analysis showed that the primary source of PAHs in Dianchi Lake surface sediments are biomass and coal combustion. Based on the potential ecological risk marker comparison method, the entire lake was classified as having a low ecological risk, while the ecological risk of Caohai was relatively higher, which should be concerned further. The results provide initial data and act as an important reference for the conservation and improvement of water quality in Dianchi Lake.