Environmental damage compensation for illegal solid waste dumping in China.

China aims to improve its system for pursuing environmental damage compensation environmental violation cases. To hold violators accountable, China has an effective system for the identification and assessment (I&A) of environmental damage. This study selected a typical case of the illegal dumping of solid waste (IDSW) in China to analyze the causes, the degree, and characteristics of environmental damage, focusing on components such as the physical quantification and valuation of damage. The findings were as follows: (1) Compensation claimants and obligors consider baseline damage confirmation and causality analysis key components of I&A. (2) The I&A process for a specific case needs to focus on key nodes such as the type, location, and duration of IDSW. (3) Restraining IDSW requires accurately quantifying the physical and value-related losses caused by solid waste dumping. (4) In the selected case study, the damage from environmental contamination caused by the IDSW incident amounted to 3938,990 yuan, including an environmental damage value of 3651,990 yuan and a transaction cost of 287,000 yuan. Both parties accepted the I&A calculation process in this case, and the desired punishment effect was achieved. Hence, the case study demonstrated that accurate I&A is the technical basis for environmental damage compensation. Thus, in the future, more attention should be paid to the role of scientific and technological means and knowledge reserves in the I&A of environmental damage.

Highly Selective and Fast Response/Recovery Cataluminescence Sensor Based on SnO2 for H2S Detection.

In the present work, three kinds of nanosized SnO2 samples were successfully synthesized via a hydrothermal method with subsequent calcination at temperatures of 500 °C, 600 °C, and 700 °C. The morphology and structure of the as-prepared samples were characterized using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, Brunauer-Emmett-Teller analysis, and X-ray photoelectron spectroscopy. The results clearly indicated that the SnO2 sample calcined at 600 °C had a higher amount of chemisorbed oxygen than the SnO2 samples calcined at 500 °C and 700 °C. Gas sensing investigations revealed that the cataluminescence (CTL) sensors based on the three SnO2 samples all exhibited high selectivity toward H2S, but the sensor based on SnO2-600 °C exhibited the highest response under the same conditions. At an operating temperature of 210 °C, the SnO2-600 °C sensor showed a good linear response to H2S in the concentration range of 20-420 ppm, with a detection limit of 8 ppm. The response and recovery times were 3.5 s/1.5 s for H2S gas within the linear range. The study on the sensing mechanism indicated that H2S was oxidized into excited states of SO2 by chemisorbed oxygen on the SnO2 surface, which was mainly responsible for CTL emission. The chemisorbed oxygen played an important role in the oxidation of H2S, and, as such, the reason for the SnO2-600 °C sensor showing the highest response could be ascribed to the highest amount of chemisorbed oxygen on its surface. The proposed SnO2-based gas sensor has great potential for the rapid monitoring of H2S.

Status of mercury accumulation in agricultural soils across China (1976-2016).

Soil contamination with mercury (Hg) is a serious and widespread issue in China, with particularly severe effects on the quality of agricultural soils. To analyse long-term, nation-wide trends in Hg contamination of agriculture soil, we conducted a review of Hg concentrations in agricultural soils over four decades, based on 791 studies comprising 1411 sites, published between 1976 and 2016. We assessed spatiotemporal variations in Hg concentration, along with ecological and health risks. While Hg concentrations in agricultural soils showed an increasing trend between 1979 and 2010, they declined thereafter. Moreover, Hg concentrations in agricultural soils were generally high in western (e.g. Guizhou), southern (e.g. Hunan) and north-eastern provinces (e.g. Liaoning), where mining activities were concentrated. Using the geoaccumulation index (Igeo) and other ecological and health risk indices, we found most sampling sites to be uncontaminated, or to have a low level of contamination, although some mining sites showed moderate to extreme Hg contamination. The noncarcinogenic risk to exposure groups followed the order of children (4.42) > adult females (2.71) > adult males (2.45). Therefore, children were identified as the priority risk group. Noncarcinogenic risk values exceeded 100 in some areas in Guizhou and Hunan provinces; these areas should be prioritised for Hg control measures. This review examined Hg pollution in Chinese agricultural soils to provide insight to policymakers for the development of targeted contamination prevention measures.

Iron minerals: A frontline barrier against combined toxicity of microplastics and arsenic.

The coexistence of microplastics (MPs) and arsenic (As) in terrestrial ecosystems presents challenges to controlling soil pollution and performing environmental risk assessments. In this study, the interactions among As, polystyrene MPs, and goethite in porous media were investigated and the individual and combined toxicities of MPs and As on wheat germination were evaluated. An additional experiment was conducted to assess the mitigating effect of goethite on the toxicity of the two contaminants. The results showed that the presence of MPs reduced As accumulation in wheat and decreased the acute lethal toxicity of As pollutants (the half-lethal concentration of As during wheat germination increased by 68.21%). However, MPs exhibited inhibitory effects on wheat germination and served as carriers to promote the migration of As within the plant body. The addition of goethite mitigated both individual and combined toxicities and further increased the half-lethal concentration for the combined pollution of As and MPs by 39.48%. This was primarily attributed to the adsorption and immobilization of arsenate and MPs on the medium and root surfaces. In our study, goethite reduced soluble As by 48.29% under the combined pollution scenarios and formed iron plaques on wheat roots, effectively obstructing pollutant entry. Thus, iron minerals serve as pioneering barriers to combined toxicity. Our findings contribute to the understanding of the combined toxicity of MPs and As in crops and offer potential strategies for managing combined pollution.

The combined toxicity of polystyrene microplastic and arsenate: From the view of biochemical process in wheat seedlings (Triticum aestivum L.).

Microplastics (MPs) are important carriers of various toxic metals and can alter their toxicity pattern in agricultural soil, leading to combined pollution, therefore posing new challenges to soil pollution management and environmental risk assessment. In this study, we observed the internalization of MPs in plants and conducted incubation experiments to evaluated the effects of arsenate (As(V)) alone and in combination with polystyrene (PS) MPs on wheat seedlings (Triticum aestivum L.). Under As(V) alone and combined with PS-MP exposure, dose-dependent toxicity in terms of root and stem elongation and biomass accumulation was observed. Compared with As(V) alone, the presence of PS-MPs reduced the accumulation of As in wheat roots by 11.43-58.91%, but PS-MPs intensified the transport of As to the aboveground parts of wheat, increasing As accumulation in wheat stems by 27.77-1011.54%. This causes more serious mechanical damage and oxidative stress to plant cells, increasing the accumulation of reactive oxygen species and lipid peroxidation in wheat roots and upregulating the activities of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). In addition, the co-exposure of As(V) and PS-MPs disrupts the photosynthetic system of wheat leaves and the secretion activities of roots. Therefore, the combination of As(V) and PS-MPs caused greater damage to wheat growth. Our findings contribute to a more comprehensive assessment of the combined toxicity of MPs and heavy metal to crops.

Bioaccumulation and risk mitigation of legacy and novel perfluoroalkyl substances in seafood: Insights from trophic transfer and cooking method.

Per- and polyfluoroalkyl substances (PFAS) have widespread application in industrial and civil areas due to their unique physical and chemical properties. With the increasingly stringent regulations of legacy PFAS, various novel alternatives have been developed and applied to meet the market demand. Legacy and novel PFAS pose potential threats to the ecological safety of coastal areas, however, little is known about their accumulation and transfer mechanism, especially after cooking treatment. This study investigated the biomagnification and trophic transfer characteristics of PFAS in seafood from the South China Sea, and assessed their health risks after cooking. Fifteen target PFAS were all detected in the samples, of which perfluorobutanoic acid (PFBA) was dominant with concentrations ranging from 0.76 to 4.12 ng/g ww. Trophic magnification factors (TMFs) > 1 were observed for perfluorooctane sulfonate (PFOS) and 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (F-53B), indicating that these compounds experienced trophic magnification in the food web. The effects of different cooking styles on PFAS occurrence were further explored and the results suggested that ΣPFAS concentrations increased in most organisms after baking, while ΣPFAS amounts decreased basically after boiling and frying. Generally, there is a low health risk of exposure to PFAS when cooked seafood is consumed. This work provided quantitative evidence that cooking methods altered PFAS in seafood. Further, suggestions to mitigate the health risks of consuming PFAS-contaminated seafood were provided.

Characteristics of Microbial Community and Function With the Succession of Mangroves.

In this study, 16S high-throughput and metagenomic sequencing analyses were employed to explore the changes in microbial community and function with the succession of mangroves (Sonneratia alba, Rhizophora apiculata, and Bruguiera parviflora) along the Merbok river estuary in Malaysia. The sediments of the three mangroves harbored their own unique dominant microbial taxa, whereas R. apiculata exhibited the highest microbial diversity. In general, Gammaproteobacteria, Actinobacteria, Alphaproteobacteria, Deltaproteobacteria, and Anaerolineae were the dominant microbial classes, but their abundances varied significantly among the three mangroves. Principal coordinates and redundancy analyses revealed that the specificity of the microbial community was highly correlated with mangrove populations and environmental factors. The results further showed that R. apiculata exhibited the highest carbon-related metabolism, coinciding with the highest organic carbon and microbial diversity. In addition, specific microbial taxa, such as Desulfobacterales and Rhizobiales, contributed the highest functional activities related to carbon metabolism, prokaryote carbon fixation, and methane metabolism. The present results provide a comprehensive understanding of the adaptations and functions of microbes in relation to environmental transition and mangrove succession in intertidal regions. High microbial diversity and carbon metabolism in R. apiculata might in turn facilitate and maintain the formation of climax mangroves in the middle region of the Merbok river estuary.

[Transfer Factor and Health Risk Assessment of Heavy Metals in a Soil-Crop System in a High Incidence Area of Nasopharyngeal Carcinoma, Guangdong].

In order to reveal the transfer factor and perform health risk assessments of heavy metals in soil-crop systems in the high incidence area of nasopharyngeal carcinoma (NPC) in Guangdong province of China, the farmland system of Sihui City in the high incidence area of NPC was selected as the research object, and rice, lettuce, and corresponding soil samples were collected. As, Cu, Hg, Mn, Ni, Pb, and Cd in the soil and crop samples were analyzed. Based on the contents and chemical forms of seven heavy metals, the environmental pollution, bioavailability, and transfer factors of heavy metals in the soil-crop system were assessed using statistical analyses, pollution index evaluations, and transfer factor methods, and the health risks of adults and children in the study area were assessed using the health risk assessment model recommended by the U.S. Environmental Protection Agency. The results showed that the farmland soil in the study area was basically clean (P=0.43); Cd and Mn mainly existed in a bioavailable state, Hg mainly existed in a potentially available state, and As Cu, Ni, and Pb mainly existed in a residual state. The lettuce was safe (P=0.48), while the pollution index of rice (P=7.66) was higher than that of lettuce, and the main polluting element was Pb (PI=10.25). The results of soil pollution assessments are not completely consistent with those of crop pollution assessments, so they should be combined with the bioavailability of heavy metals and crop effects for correlation analyses. Cd and Cu are more easily absorbed by lettuce, while Cd, Cu, and As are more easily enriched by rice. Special attention should be paid to Cd and Cu pollution in farmland soils, and As pollution should be of focus in paddy fields. In the study area, the non-carcinogenic risk index (HI) value of edible lettuce for adults and children was less than 1 and the average value of the total carcinogenic risk index (Risk) of edible lettuce was less than 1×10-4. Therefore, the health risk of edible local lettuce was within the acceptable range. The average HI index of rice for adults and children was more than 1 and the main non-carcinogenic factor was Pb; the risk index of rice was more than 1×10-4, and the main carcinogenic factor was As. Rice consumption in the study area will cause certain health risks, and the threat to adults is greater than that to children. Therefore, As in rice may be related to the high incidence of NPC in Sihui City. It is suggested that the remediation of heavy metals in farmland soils be strengthened or that residents be forbidden to plant or eat local rice and other crops with greater health risks.

GV20-based acupuncture for animal models of acute intracerebral haemorrhage: a preclinical systematic review and meta-analysis.

BACKGROUND: Spontaneous intracerebral haemorrhage (ICH) is the most devastating subtype of stroke, but there is currently no evidence-based treatment strategy. Acupuncture is a well-known traditional Chinese therapy for stroke-induced disability, and GV20 is the commonly used acupuncture point. OBJECTIVE: To evaluate the efficacy of GV20-based acupuncture in animal models of acute ICH. METHODS: Studies of GV20-based acupuncture in animal models of acute ICH were identified from six databases up to July 2013. Study quality for each included article was evaluated according to the CAMARADES 10-item checklist. Outcome measures were neurological deficit scores and brain water content. All the data were analysed using RevMan V.5.1 software. RESULTS: Nineteen studies were identified describing procedures involving 1628 animals. The quality score of the studies ranged from 3 to 6, with a mean of 4.6. The global estimate of the effect of GV20-based acupuncture was 0.19 (95% CI 0.13 to 0.25, p<0.001) SDs improvement in outcome compared with controls. In subgroup analyses, size of effect was higher where the outcome was measured as the neurological deficit score than the brain water content or both (p<0.001). CONCLUSIONS: These findings show the possible efficacy of GV20-based acupuncture in animal models of acute ICH, suggesting it as a candidate therapy for acute ICH.