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As an important commercial form of vanadium, vanadium pentoxide (V2O5) is widely used in various modern industries, and its environmental impacts and ecotoxicity have been extensively studied. In this research, the ecotoxicity of V2O5 to earthworms (Eisenia fetida) in soil was tested by exposure to V2O5 at a series of doses, and biochemical response indices, such as the superoxide dismutase (SOD) and catalase (CAT) enzyme activity and malondialdehyde (MDA) content, were analysed to determine the mechanism by which antioxidant enzymes respond to V2O5 exposure. The bioaccumulation factor (BAF) of vanadium pentoxide in the earthworms and soil was also measured to explore the bioaccumulation process of V2O5 in the test period. The results showed that the acute and chronic lethal toxicity values of V2O5 towards E. fetida were 21.96 mg/kg (LC50, 14 days) and 6.28 mg/kg (LC10, 28 days), respectively. For the antioxidant enzymes, SOD and CAT were synchronously induced or inhibited within the time period, and the enzyme activity had a dose-effect relationship with the V2O5 concentration. MDA analysis indicated that lipid peroxidation in earthworms mainly occurred at the early stage and was eliminated slowly in the later stage during the test time. In addition, the BAFs were much less than 1, which indicated that V2O5 did not easily accumulate in earthworms, and the BAF was positively correlated with the exposure time and negatively linearly correlated with the V2O5 concentration in the soil. These results indicated that the bioconcentration and metabolic mechanism of V2O5 in earthworms differed with the different exposure concentrations, and bioaccumulation became balanced after 14-28 days in earthworms exposed to a relatively lower dose of V2O5. The analysis of the integrated biomarker response (IBR) index indicated that the trends of IBR values were positively related to the changing V2O5 concentration, and the IBR index could reflect the organism’s sensitivity to the external stimulus of V2O5. The toxicity of V2O5 is mainly caused by V5+, which is also an important factor in formulating guidelines regarding vanadium levels in soil, and the test earthworm species (Eisenia fetida) is a sensitive biological indicator for risk assessments of vanadium oxidation in the soil.

Pentachlorophenol (PCP) has been widely used as an insecticide for killing oncomelania (the intermediate host of schistosome) in China and leads to severe environmental contamination. Poyang Lake, as the largest freshwater lake and bird habitat in China, was once a schistosomiasis epidemic area. In this study, the concentrations of PCP in water and aquatic products from Poyang Lake were determined and analyzed, and then the human health ambient water quality criteria (AWQC) was derived based on native parameters of Poyang Lake basin. Finally, a comprehensive analysis of the health risks of drinking water and different types of aquatic products consumption was carried out. The results showed that PCP concentrations were ranged from 0.01 to 0.43 μg/L in surface water and 3.90 to 85.95 μg/kg in aquatic products. Due to the carcinogenicity of PCP, the human health AWQC for PCP are 0.02 μg/L for consumption of water and organisms and 0.03 μg/L for consumption of organisms only. Deterministic and probabilistic risk analysis indicated that the non-carcinogenic risk of PCP were acceptable in Poyang Lake, while the carcinogenic risk cannot be ignored. The health risks of PCP caused by aquatic products consumption were higher than that by drinking water. The percentages of acceptable risk for the population in Poyang Lake Basin were 99.95% at acceptable level of 10

Ecological risks can vary dramatically depending on abiotic factors, such as soil properties and the background values of elements. This study developed a framework for an integrated risk assessment system to derive soil quality criteria (SQC) for heavy metals (HMs) applicable to different soil types and to assess ecological risks at a multi-regional scale. Through the construction of normalization and species sensitivity distribution models, 248 SQC values for Cd, Pb, Zn, As, Cu, Cr, Sb, and Ni in 31 Chinese provinces were derived. These SQC considered the soil types and background values of the elements and effectively reduced the uncertainty caused by spatial heterogeneity. Using the derived SQC values, the qualitative and quantitative ecological risks of HMs in the terrestrial environment of China were comprehensively assessed using a three-level ecological risk assessment (ERA) approach. Compared to traditional ERA methods, the new methodology reached a more quantitative conclusion. The mean overall probabilities of ecological risk in China were 2.42 % (Cd), 2.82 % (Pb), 12.17 % (Zn), 14.89 % (As), 10.42 % (Cu), 32.20 %(Cr), and 8.88 % (Ni). The new framework could be useful for the ERA of various soil types.

Phthalate esters (PAEs) are a class of endocrine disruptors that are produced and used extensively in China. Given its presence in various products, a great quantity of PAEs flows into different aquatic systems each year. Hence, it is important to study the pollution levels and ecological risk of PAEs. This study investigated the distribution and seasonal variation of six priority PAEs in the surface water of Poyang Lake, the largest freshwater lake in China. In the wet season, the mean concentration of the total PAEs was 0.544 ± 0.173 μg/L, while the dry season concentration (1.003 ± 0.451 μg/L) nearly doubled. The most abundant PAE congeners were di-n-butyl phthalate (DBP), followed by bis (2-ethylhexyl) phthalate (DEHP). To evaluate the ecological risks in Poyang Lake, the predicted no-effect concentrations (PNECs) of four PAEs based on non-lethal effects were derived. For diethyl phthalate (DEP), butyl benzyl phthalate (BBP), DBP, and DEHP, the PNECs were 31.6, 3.30, 2.31, and 0.0210 μg/L, respectively. The tiered ecological risk assessment showed that DEP and BBP posed no risk in Poyang Lake. Meanwhile, DBP posed a potential risk in Poyang Lake, but the risk of DEHP was unacceptable and requires more actions. Specifically, the probabilities of exceeding the threshold for the protection of 95% of the aquatic organisms (HC5) were 3.30% and 4.43% for DEHP in the wet and dry season, respectively. This study provides an appropriate reference for the surface water management of PAE pollution in China.

Perfluorooctane sulfonate (PFOS) is a synthetic substance with a great number of applications. However, it persists in the environment and is potentially toxic to organisms. Although China has been the main manufacturer and consumer for PFOS, the national pollution level and potential risk of this chemical are yet to be determined. This study aimed to provide an overview of PFOS contamination in surface and drinking water across China and to assess the potential ecological and health risks. Available monitoring data for PFOS in surface and drinking water were evaluated. PFOS was found to be ubiquitous in China, but the overall level of contamination was low compared with that in other countries. The southeast coastal area of China, with major PFOS-related companies, was characterized by relatively high PFOS exposure concentrations. The most sensitive effects was screened and applied to assess the ecological risk using the joint probability curve method. The probability of exceeding the growth and development toxicity for 5% of aquatic species was 0.65% in Chinese surface waters, while the highest probability of 0.90% was in Tai Lake in east China. Considering the average daily dose (ADD) for the Chinese population, the health risk posed by PFOS through drinking water ranged from 1.31 × 10−4 to 13.91. Besides the relatively high health risk existed in east China, most health risks in China were acceptable.

Triclocarban (TCC) is used as a broad-spectrum antimicrobial agent, the intensive detection of TCC in aquatic environments and its potential risks to aquatic organisms are concerned worldwide. In this study, 8 Chinese resident aquatic organisms from 3 phyla and 8 families were used for the toxicity tests, and four methods were employed to derive the aquatic life criteria (ALC). A criterion maximum concentration (CMC) of 1.46 μg/L and a criterion continuous concentration (CCC) of 0.21 μg/L were derived according to the USEPA guidelines. The acute predicted no effect concentrations (PNECs) derived by species sensitivity distribution (SSD) methods based on log-normal, log-logistic and Burr Type Ⅲ models were 2.64, 1.88 and 3.09 μg/L, respectively. The comparisons of ALCs derived with resident and non-resident species showed that the CMC and CCC of TCC derived with Chinese resident species could provide a sufficient protection for non-resident species. The higher toxicity of TCC on aquatic organisms was found compared with other antimicrobial agents (except for Clotrimazole) in aquatic environment. The strong positive linear correlation was observed between the TCC and TCS concentrations in aquatic environment with a correlation coefficient (R2) of 0.8104, it is of great significance in environmental monitoring and risk assessment for TCC and TCS. Finally, the ecological risk assessment showed that the TCC in Yellow River basin and Pearl River basin had higher risk with the mean potential affected fractions (PAFs) of 9.27% and 7.09%, and 22.10% and 15.00% waters may pose potential risk for 5% aquatic organisms, respectively. In general, the risk of TCC in Asian waters was higher than that in Europe and North America.

N,N-diethyl-meta-toluamide (DEET) is the most widely used active ingredient in commercial insect repellents. In addition to its adverse effects in insects, DEET can affect non-target organisms in surface water systems. Nevertheless, the aquatic life criteria of DEET are not available. This study conducted both acute and chronic toxicity tests on DEET in native Chinese aquatic species, and derived its criterion maximum concentration (CMC) and criterion continuous concentration (CCC). The determined CMC and CCC of DEET were 21.53 and 0.52 mg/L, respectively. The toxicity data indicated that DEET exposure posed a higher toxicity to some algae than other aquatic species. Compared with other insect repellents, DEET exposure posed a moderate toxicity to aquatic species. Therefore, the exposure concentration of DEET in Chinese surface water was collected to assess the potential ecological risk. The preliminary ecological risk assessment showed that DEET posed negligible risk to aquatic ecosystems in China. However, considering its toxic effects on the growth and reproduction to aquatic organisms, the ecological risk posed by DEET is worth further concern.