Due to the high threat to human health and the ecosystem from metals, the levels and distribution of As, Hg, Cr, Co, Ni, Cu, Zn, Cd, Pb, Mn, V, Sn, Sb, Li and Be in various layers of soil from an e-waste recycling area in Guiyu, China were investigated. The extent of pollution from the metals in soil was assessed using enrichment factors (EFs) and the Nemerow pollution index (P N ). To determine the metals' integrated potential ecological risks, the potential ecological risk index (RI) was chosen. The concentrations of Hg, Ni, Cu, Cd, Pb, Sn and Sb were mainly enriched in the topsoil. EF values (2-5) of the elements Hg, Co, Ni, Zn, Sn, Li and Be revealed their moderate enrichment status in the topsoil, derived from e-waste recycling activities. P N presented a decreasing trend in different layers in the order topsoil (0-20 cm) > deep soil (100-150 cm) > middle soil (50-100 cm) > shallow soil (20-50 cm). With higher potential ecological risk factor (E(i)), Hg and Cd are the main contributors to the potential ecological risk. With respect to the RI, all the values in soil from the study area exceeded 300, especially for the soil at sites S2, S4, S5, S7 and S8, where RI was greater than 600. Therefore, immediate remediation of the contaminated soil is necessary to prevent the release of metals and potential ecological harm.

Human exposure to organophosphate esters (OPEs) is more pervasive in industrial areas manufacturing OPE-related products. OPE exposure is of great concern due to its associations with adverse health effects, while studies on OPE exposure in industrial districts are scarce. This study aimed to assess human exposure to OPEs in a typical industrial area producing large amounts of OPE-related products in Shenzhen, China. Tris (2-chloroethyl)-phosphate (TCEP), tris (2-chloroisopropyl) phosphate (TCPP) and other common OPEs were analyzed in urine (n = 30) and plasma (n = 21) samples. Moreover, we measured five OPE metabolites (mOPEs) in plasma samples (n = 21). The results show that TCPP and TCEP are dominant compounds, with moderate to high levels compared with those reported in urine and plasma samples from other regions. In addition, di-n-butyl phosphate (DnBP) and diethyl phosphite (DEP) were frequently detected in plasma samples and could be considered as biomarkers. Risk assessment revealed a moderate to high potential health risk from TCEP exposure. Our results provide basic data for human exposure to OPEs in industrial areas and call for the prevention and mitigation of industrial chlorinated OPE pollution.

Twelve polybrominated diphenyl ethers (PBDEs) were measured in water, suspended particulate matter (SPM) and sediment samples during dry season (DS) and wet season (WS), to explain the spatiotemporal distribution, congener pro les, sources and risks of the pollutants in four reservoirs (A-D) and their tributaries of a large city in South China. The concentration of ∑ 12 PBDEs ranged from 0.46 to 2.27 ng/L (average: 1.41 ng/L) in water during WS, and from 0.70 to 13.04 ng/L (3.77 ng/L) during DS.Meanwhile, the content of ∑ 12 PBDEs ranged from 9.71 to 364.14 ng/g dry weight (the same below) (170.23 ng/g) in SPM during WS, and from 53.48 to 1043.69 ng/g (313.37 ng/g) during DS. The content of ∑ 11 PBDEs (excluding BDE-209) ranged from 24.70 to 222.75 ng/g (85.86 ng/g), while that of BDE-209 ranged from 4.74 to 31053.11 ng/g (6307.93 ng/g) in sediment during WS. ∑ 12 PBDEs during DS were signi cantly higher than WS. Source apportionment suggested that commercial penta-, octa-and deca-BDEs were major compositions of PBDEs, resulting mainly from atmospheric deposition, wastewater discharge and external water diversion project. Among the related enterprises, attentions should be paid to electronic equipment manufacturing factories in this study area. The risk assessment indicated low ecological and insigni cant human health risks posed by PBDEs in water, but the risk of PBDEs (especially BDE-209) in sediment and SPM was of particular concern. The present study would provide important data and support for the control of PBDEs in natural drinking water sources.

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Twelve polybrominated diphenyl ethers (PBDEs) were measured in water, suspended particulate matter (SPM) and sediment samples during dry season (DS) and wet season (WS), to explain the spatiotemporal distribution, congener profiles, sources and risks of the pollutants in four reservoirs (A-D) and their tributaries of a large city in South China. The concentration of ∑12PBDEs ranged from 0.46 to 2.27 ng/L (average: 1.41 ng/L) in water during WS, and from 0.70 to 13.04 ng/L (3.77 ng/L) during DS. Meanwhile, the content of ∑12PBDEs ranged from 9.71 to 364.14 ng/g dry weight (the same below) (170.23 ng/g) in SPM during WS, and from 53.48 to 1043.69 ng/g (313.37 ng/g) during DS. The content of ∑11PBDEs (excluding BDE-209) ranged from 24.70 to 222.75 ng/g (85.86 ng/g), while that of BDE-209 ranged from 4.74 to 31053.11 ng/g (6307.93 ng/g) in sediment during WS. ∑12PBDEs during DS were significantly higher than WS. Source apportionment suggested that commercial penta-, octa- and deca-BDEs were major compositions of PBDEs, resulting mainly from atmospheric deposition, wastewater discharge and external water diversion project. Among the related enterprises, attentions should be paid to electronic equipment manufacturing factories in this study area. The risk assessment indicated low ecological and insignificant human health risks posed by PBDEs in water, but the risk of PBDEs (especially BDE-209) in sediment and SPM was of particular concern. The present study would provide important data and support for the control of PBDEs in natural drinking water sources.