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Coix lacryma-jobi L. is a traditional medicinal plant in east Asia and is an important crop in Guizhou province, southwest China, where there are elevated levels of soil mercury and arsenic (As). Exposure to multiple potentially toxic elements (PTEs) may affect plant accumulation of metal(loid)s and food safety in regions with high geological metal concentrations. Field experiments were conducted to study the effects of PTEs on metal(loid) accumulation and physiological response of C. lacryma in different plant parts at three pollution levels. Total root length, number of root tips, number of branches, and number of root crosses increased with increasing pollution level, with increases in highly polluted areas of 44.2, 57.0, 79.6, and 97.2%, respectively, compared to lightly polluted areas. Under multi-element stress the activity of C. lacryma antioxidant oxidase showed an increase at low and medium PTE concentrations and inhibition at high concentrations. The As contents were all below the maximum limit of cereal food contaminants in China (GB 2762-2022, As < 0.5 mg kg−1). The stems had high Tl bioconcentration factors but the translocation factors from stem to grain were very low, indicating that the stems may be a key plant part restricting Tl transport to the grains. C. lacryma increased root retention and reduced the transport effect, thus reducing metal accumulation in the grains. C. lacryma adapted to PTE stress through root remodeling and enhanced antioxidant enzyme activities. [ABSTRACT FROM AUTHOR]

Accurate prediction of cadmium (Cd) ecotoxicity to and accumulation in soil biota is important in soil health. However, very limited information on Cd ecotoxicity on naturally contaminated soils. Herein, we investigated soil Cd ecotoxicity using Folsomia candida, a standard single-species test animal, in 28 naturally Cd-contaminated soils, and the back-propagation neural network (BPNN) model was used to predict Cd ecotoxicity to and accumulation in F. candida. Soil total Cd and pH were the primary soil properties affecting Cd toxicity. However, soil pH was the main factor when the total Cd concentration was < 3 mg kg−1. Interestingly, correlation analysis and the K-spiked test confirmed nutrient potassium (K) was essential for Cd accumulation, highlighting the significance of studying K in Cd accumulation. The BPNN model showed greater prediction accuracy of collembolan survival rate (R2 = 0.797), reproduction inhibitory rate (R2 = 0.827), body Cd concentration (R2 = 0.961), and Cd bioaccumulation factor (R2 = 0.964) than multiple linear regression models. Then the developed BPNN model was used to predict Cd ecological risks in 57 soils in southern China. Compared to multiple linear regression models, the BPNN models can better identify high-risk regions. This study highlights the potential of BPNN as a novel and rapid tool for the evaluation and monitoring of Cd ecotoxicity in naturally contaminated soils. [ABSTRACT FROM AUTHOR]

Heavy metal (HM) pollution nowadays is a hot issue concerning global ecological and food safety. As one of the most important woody bamboos for edible shoots in Southeast Asia and southwest China, Dendrocalamus brandisii usually occurs in red soil with a high HM geological background. However, the bioaccumulation process and possible risks of HMs in their cultivation area remain unclear. In this study, a comprehensive risk assessment of HM pollution was conducted in the main cultivation area of D. brandisii under two cultivation patterns in Yunnan, China. The results revealed that moderate to heavy HM pollution existed in the soil of the study area, while bamboo shoots displayed either no pollution or weak contamination. The "large-area intensive afforestation" cultivation pattern can better control HM pollution in soil and shoots than the "small-scale farmer management" pattern. Strong and complex correlations among HMs were unveiled in both soil and shoot samples. The Cr content of 39% of the shoot samples exceeded China's national standards. Cu and Zn were the two most easily accumulated HMs in shoots, with BCF of 0.1235 and 0.1101, respectively. Bioaccumulations of As and Cd were positively correlated with their concentrations in soil. Furthermore, the positive matrix factorization model (PMF) identified three main sources of soil HMs, i.e., Pb and Zn from traffic emissions accounting for 30%; Ni, Mn, and Cr from pedogenic parent material making up 35.4%; and As from mining and metallurgical activities accounting for 34.6%. Monte Carlo simulations suggested the probability of total noncarcinogenic risk for children from bamboo shoots was 24.82% and that As in the soil was the primary element of health risk to children (HQc = 13.94%). These findings emphasize the urgent need to control and mitigate HM pollution from the identified sources and may contribute to the sustainable cultivation of D. brandisii and food safety in Yunnan and similar tropical areas with high HM contents. [ABSTRACT FROM AUTHOR]

Dried roots and rhizomes of Rubia yunnanensis are ethnic medicines in the southwest region of China. The effects of well-watered control (C), moderate drought (MD), severe drought (SD), and re-watering after moderate drought (RMD) on basic physiological traits and accumulation of anthraquinones (AQs) were investigated in roots and rhizomes of R. yunnanensis. The results indicated that significantly increased superoxide anion, hydrogen peroxide and malondialdehyde contents were accompanied by enhanced superoxide dismutase, peroxidase, catalase activities and proline content in R. yunnanensis roots and rhizomes during MD and SD treatments. There were strong correlations between the stress indices and antioxidant enzymes, which promoted each other and responded to soil moisture changes synergistically. Additionally, moderate drought-induced damage was reversible, and physiological indicators almost completely recovered for RMD plants. Majority of AQs were significantly improved in MD or RMD treatment. In vitro antioxidant test showed that scavenging radical ability was positively related to AQs, particularly significant at P = 0.05 with the contents of xanthopurpurin, rubiquinone and 1,3,6-trihydroxy-AQ, demonstrating these AQ aglycones played an antioxidative protection under MD stress. This study revealed that moderate drought or after water recovery may be an effective way to guarantee normal plant growth and improve the quality of medicinal materials. [ABSTRACT FROM AUTHOR]

The organochlorine pesticides (OCPs) are with features of persistence, high toxicity, bioaccumulation and adverse impact on ecosystems and human beings. Although OCPs pollutions have been observed in the plateau lakes, comprehensive understandings in the distribution characteristics and human health risks of OCPs in these valuable but fragile ecosystems are limited. We here investigated the distribution, bioaccumulation process and health risks of OCPs in the Jianhu lake, a representative plateau lake in China. The endrin ketone, endrin aldehyde and heptachlor were the most dominant species in surface and columnar sediments. Their total contents ranged between 0 ~ 1.92 × 103 ng·g−1. The distribution of OCPs in sediment cores combined with chronology information indicated that the fast accumulation of OCPs happened during the last decades. Combining the distribution features of OCPs in different sources with mixing model results of carbon isotope (δ13C), farming area was identified as the main source (46%), and the OCPs were transported to lake by inflow-rivers (37%). The enrichment of OCPs in sediments caused considerable bioaccumulation of OCPs in local fish (∑OCPs 0–3199.93 ng·g−1, dw) with the bio-sediment accumulation factor (BSAF) ranging from ND to 9.41. Moreover, growing time was another key factor governing the accumulation in specific species (Carassius auratus and Cyprinus carpio). Eventually, the carcinogenic risk index (CRI) and exposure risk index (ERI) of the endrin category and aldrin exceeded the reference value, indicating relatively high health risks through consumption of fish. Overall, this study systematically illustrated the bioaccumulation process and health risks of OCPs in the typical plateau lake, providing theoretical support for the better protection of this kind of lakes. [ABSTRACT FROM AUTHOR]

Plastic‐related contaminants in the environment have attracted increasing attention, with plastic pollution becoming a serious issue globally. The present study investigated the potential bioaccumulation and biotransfer of bisphenol (BP) compounds that are widely added in various products such as plastics and other products in a freshwater ecosystem, China. Among commonly applied 14 BP analogues, bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS) were predominant, representing 64%–100% of the total concentrations of BPs (ΣBPs) in freshwater wildlife. Both the concentrations and analogue profiles in the fish showed seasonal differences and species dependence. Higher BP concentrations were observed in fish collected during the dry season than the wet season. Higher percentages of non‐BPA analogues (e.g., BPS and BPF) were observed in fish collected during the wet season. Pelagic species accumulated notably higher levels of BPs than midwater and bottom species. The liver generally contained the highest ΣBPs, followed successively by the swim bladder, belly fat, and dorsal muscle. The analogue profile also showed some differences among tissues, varying by species and season. Lower ΣBPs but higher percentages of non‐BPA analogues were observed in female than male common carp. Time trends of the BPA concentration in fish varied by species, probably related to habitats and diets of the fish. Habitats, feeding behaviors, and trophic transfer may have significant impacts on exposure of wildlife to BPs in natural ecosystems. The BPs did not demonstrate strong potential for bioaccumulation. More research is warranted about metabolism and transgenerational transfer of BPs in wildlife to fully reveal the bioaccumulation and consequently ecological risks of these chemicals in the environment. Environ Toxicol Chem 2023;42:2130–2142. © 2023 SETAC [ABSTRACT FROM AUTHOR]

The present study investigated the bioaccumulation and translocation of mercury (Hg) and chromium (Cr) in Yunyan 87 flue-cured tobacco (Nicotiana tabacum) and assessed the influence of soil pH on the metal uptake by plant organs at the field scale. The study was conducted in 4 different regions selected from Sichuan Province, China: Guangyuan, Luzhou, Panzhihua, and Yibin. The results revealed that Hg highly contaminated Yibin soils at 0.29 mg kg−1 and by Cr at 147 mg kg-1, which is above the permissible limit. The levels of Hg in tobacco plant organs were predominantly in the order of leaves > root > stem. The overall trend for Cr contents in tobacco organs was in the order of root > leaves > stem. The results of an index of bioaccumulation (IBA) and translocation factor (TF) showed that the values observed in Panzhihua and Guangyuan tobacco leaves were generally higher, despite the low levels of soil contamination. The linear mixed model (LMM) demonstrated that the log of Hg IBA in tobacco organs was likely to decrease with soil pH increase, whereas the log of Cr IBA only decreased in the root but gradually increased in the aerial parts with soil pH increase. The total random variation in the log of metals' IBA due to regions indicated that for Hg, 33.42% of the variation was explained by regional differences, while for Cr, only 13% was accounted. The results suggested that Yibin and Luzhou need to correct the soil acidity if they are set to reduce Hg contamination in tobacco-growing soils. Guangyuan and Panzhihua need efforts to keep the soil pH on track to avoid high contamination levels, and effective measures of soil nutrients supply are required to produce high tobacco leaf quality free from heavy metal content. The findings of this study may be used to ascertain regional differences in heavy metals, particularly Hg and Cr uptake by tobacco plant organs, and to prevent the cultivation areas contamination through soil pH monitoring. [ABSTRACT FROM AUTHOR]

The excessive application of herbicides on farmlands can substantially reduce labor costs and increase crop yields, but can also have undesirable effects on terrestrial ecosystems. To evaluate the ecological toxicity of herbicides, metolachlor and fomesafen, two typical herbicides that are extensively used worldwide were chosen as target pollutants, and the endogeic earthworm Pheretima guillelmi, which is widely distributed in China, was selected as the test organism. A laboratory-scale microcosmic experiment was set, and energy resources, enzymes, and the composition and connections of intestinal microorganisms in earthworms were determined. Both herbicides depleted the energy resources of the earthworms, especially glycogen contents; increased the levels of antioxidant enzymes; and inhibited acetylcholinesterase. Moreover, the richness and diversity of the intestinal bacterial community of the earthworms were suppressed. Additionally, the bacterial composition at the genus level changed greatly and the connections between dominant bacteria increased dramatically. Most interactions among the bacterial genera belonging to the same and different phyla showed mutualism and competition, respectively. Importantly, metolachlor with higher toxicity had a transitory effect on these indicators in earthworms, whereas fomesafen, with lower toxicity but stronger bioaccumulation potential, exerted a sustaining impact on earthworms. Collectively, these results indicate that the toxic effects of herbicides on terrestrial organisms should be comprehensively considered in combination with biological toxicity, persistence, bioaccumulation potential, and other factors. [ABSTRACT FROM AUTHOR]

The phosphorus provision and heavy metal toxicity are two main factors limiting the crop yield and quality in contaminated soils in South China. In order to find efficient and affordable methods of simultaneously enhancing phosphorus uptake and reducing cadmium uptake by plants, phosphate-solubilizing bacteria capable of Cd(II) immobilization were screened and the relevant process was investigated in this study. From cadmium-contaminated soil, we ultimately isolated one phosphate-solubilizing bacteria, Bacillus sp. B19, can dissolve tricalcium phosphate, aluminum phosphate, and iron phosphate when Cd(II) is added. By biosorption, bioaccumulation, and precipitation, Bacillus sp. B19 was able to solubilize phosphate while immobilizing Cd(II). Initial pH, contact time, and initial Cd(II) concentration could all have an impact on Bacillus sp. B19's ability to biosorb Cd(II). By using the Langmuir isotherm, the maximum Cd biosorption of strain B19 was determined to be 10.66 mg/g. Pseudo-second-order kinetic modeling provided a better explanation of the biosorption's kinetics. The Cd(II) biosorption by strain B19 was also investigated using zeta potential, scanning electron microscopy (SEM) combined with an energy dispersive spectrometer, and Fourier transform infrared spectroscopy (FTIR). When Cd(II) concentrations were low and high, strain B19's Cd(II) biosorption was primarily intracellular bioaccumulation and surface bioadsorption. Our findings show that strain B19 may be an effective option for immobilizing Cd(II) in soils contaminated with Cd, in addition to being a viable candidate for supplying nutrients. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) have the characteristics of high toxicity, long residual time, and difficult degradation, which pose a potential threat to aquatic ecosystems. The distribution and migration of HMs in different media can reflect their potential impact on aquatic ecosystem health. In this study, we analyzed the distribution characteristics of seven HMs (Zn, Cu, Cr, Ni, Hg, As, and Pb) in the water and sediment and five groups of organisms (fish, Crustacean, cephalopod, bivalvia, and gastropoda) in the sea ranching area of Haizhou Bay and explored the regularity of HM accumulation from water and sediments to organisms. The results showed that in the water, Zn and Hg had the smallest concentrations in the nearshore area, Cr had the lowest concentrations in the offshore area, and As, Cu, Pb, and Ni had the lowest concentrations in the central area. In the sediment, Hg had the smallest concentrations in the nearshore area and As, Pb, Cr, Cu, Ni, and Zn had the lowest concentrations in the offshore area; the average contents of seven heavy metals all meet the Class I standard of sediments in China. The concentrations of Cu and Zn in crustaceans were significantly higher than those in fishes (p < 0.05), and As showed a higher enrichment effect in cephalopods. Under the influence of feeding habits and habitat environment, the BAF value of benthic crustaceans and bivalvia accumulated HMs from sediments is high, and the BAF value of fish accumulated HMs from water and sediments is low. Overall, the concentration of HMs in water is high, and HMs in sediments are in good condition, crustaceans and bivalviaa have a strong ability to accumulate HMs from water and sediments, while fish are weak. Therefore, in order to ensure the safety of biological quality, it is necessary to focus on the discharge of heavy metal pollutants near the coast in the future. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze levels of heavy metals and human health risk implications associated with fish consumption from the Yangtze River. A total of 60 fish muscles were taken from six different fish species—Hypophthalmichthys molitrix, Ctenopharyngodon idellus, Blicca bjoerkna, Mylopharyngodon piceus, Carassius carassius and Pelteobagrus fulvidraco—and digested using standard protocols. Contents of lead (Pb), cadmium (Cd), zinc (Zn), aluminum (Al) cobalt (Co), manganese (Mn), chromium (Cr), and copper (Cu), were analyzed using an Atomic Absorption Spectroscophotometer ((ZEEnit 700 P Zeeman)). Based on consumer health risk indicators, the health implications to children and adults upon consuming the analyzed fish species were assessed. Findings revealed that Zn recorded the highest mean concentration of 9.87 µg/g in Carassius carassius followed by Mn (7.97 µg/g) in Pelteobagrus fulvidraco, Cu (2.07 µg/g) in Mylopharyngodon piceus, Pb (1.04 µg/g) in Hypophthalmichthys molitrix, Cr (0.63 µg/g) in Hypophthalmichthys molitrix, Cd (0.19 µg/g) in Blicca bjoerkna and Ni (0.16 µg/g) (w/w) in Pelteobagrus fulvidraco. In addition, the health risk assessments revealed that children are at heightened non-carcinogenic risk for Pb, Cd, and Co upon consuming the examined fish species. [ABSTRACT FROM AUTHOR]

Dietary uptake is well known as the predominant pathway of heavy metal bioaccumulation in organisms. Our study used a typical tropical reservoir and fish as a modeling system to test the hypothesis that feeding habits and living habitats significantly affect heavy metal bioaccumulation in fish. Specifically, Cr, Mn, Fe, Ni, Cu, Zn, Cd, and Pb concentrations in water, sediment, and fish, and δ13C and δ15N in 13 fish species were detected in the Songtao Reservoir of Hainan Province, southern China. Our results indicated that Zn concentration in carnivorous fish was higher than in omnivorous fish. Principal components analysis visually differentiated pelagic, benthopelagic, and demersal fish groups. Moreover, we found that the fish feeding in the demersal habitat showed higher heavy metal levels than those in the pelagic habitat. Additionally, the heavy metal contents in demersal fish were significantly positively correlated with sediments, while no positive correlation was observed in pelagic-feeding fish. The δ15N and the concentration of Ni, Zn in fish had a significantly positive correlation, suggesting the potential biomagnification. In contrast, Ni, Fe, Cu, and Cd negatively correlated with fish body weight/length, indicating the growth dilution effects. Finally, the estimated daily intake (EDI) of the metals was far below the provisional tolerable daily intake (PTDI), and target hazard quotients (THQ) were <1.0, indicating that the fish had no risk for consumption risks. Overall, our finding partially validated the hypothesis that the feeding habits and living habitats significantly influence heavy metal bioaccumulation in fish, which might be a broad generality for metal exposure scenarios in aquatic environments. [ABSTRACT FROM AUTHOR]

The coupling cycles of soil carbon (C), nitrogen (N), and phosphorus (P) have a significant impact on biogeochemical processes and ecosystem services. For centuries, large areas of floodplain wetlands in China have been extensively reclaimed for agricultural purposes due to population growth. However, little is known about the evolution of soil C:N:P stoichiometry along a reclamation chronosequence, particularly across different land uses. In this study, we investigated the variations in soil C:N:P ratios with land use and time gradients along a reclamation chronosequence comprising c. 0, 60, 100, 280, 2000, and 3000 years. Land reclamation induced nutrient decoupling, as it facilitated C and N accumulation from biological processes but restricted P supply controlled by geochemical processes. Soil C and N sequestration reached a stable state after 2000 years, while P declined steadily from 60 years. Soil C/P and N/P increased significantly and were controlled by organic carbon (OC) and total nitrogen (TN), respectively, indicating that an increase in C and N could also promote P uptake. Soil C/N declined in the first 60 years and stabilized at a threshold of 10:1. Different land use patterns following reclamation resulted in distinct soil nutrient structures. Paddies retained more OC and TN but exhibited lower adsorption of total phosphorus (TP) compared to adjacent dryland, leading to significant differences in C/P and N/P between land uses. Based on the redundancy analysis and random forest model, soil OC and TN were mainly affected by the abundance of bacteria metabolizing cellulose, while metal oxides, including Fe2O3 and CaO, could best predict TP. Soil C/P and N/P were mainly driven by soil texture and rose significantly with the increasing proportion of clay particles. Our study suggests that as reclamation proceeds, more anthropogenic management is required to regulate potential nutrient imbalances in order to prevent adverse effects on crop growth, soil quality, and ecosystem health. Additionally, any fertilization strategy should be developed based on dryland C and N deficiencies, and lack of P in paddies. [ABSTRACT FROM AUTHOR]

In order to assess the metal pollution in the Wujiang River, concentrations of Cu, Zn, Fe, Mn, Pb, Cd, As, and Hg in the water, sediments, and two fish species Cyprinus carpio and Pelteobagrus fulvidraco from the middle reaches (Tuomugang, TMG) and lower reaches (Wulong, WL) of the Wujiang River were examined. The results indicated that all metal concentrations were lower than the values for grade one water quality according to the Environment Quality Standard for Surface Water of China (GB 3838–2002). The bioavailable fraction concentrations of Zn, Fe, Mn, Pb, and Hg in WL were significantly higher than those in TMG (p < 0.05), indicating that these metals in sediments of WL have higher bioavailability and mobility. The Cu, Zn, Fe, Pb, As, and Hg were mainly related to the residual fraction, while the Mn and Cd were mainly associated with the non-residual fraction. The risk assessment code (RAC) and the secondary phase to the primary phase (RSP) values indicated that Mn and Cd have a high risk of secondary release. The mean metal concentrations in the liver of the two fish species were higher than those in muscle. The higher metal concentrations of fish in WL suggested that bioaccumulation of metals in fish could be influenced by metal bioavailability. No identical relationships between metal concentrations and fish length were manifested in the present study. The values of target hazard quotient (THQ) and hazard index (HI), and carcinogenic risk (CR) of metals for the consumption of C. carpio and P. fulvidraco indicated that the anglers would likely not experience significant non-carcinogenic risk, but the carcinogenic risk of As cannot be ignored. Thanks to prohibited commercial fishing in the Wujiang River, the metal pollution will probably not pose a health risk to the general public for wild fish consumption. [ABSTRACT FROM AUTHOR]

Mono-chlorinated products of cyclic volatile methylsiloxanes (cVMS), i.e., Monochlormet-hylheptamethylcyclotetrasiloxane [D3D(CH 2 Cl)], monochlormethylnonamethylcyclopenta-siloxane [D4D(CH 2 Cl)], and monochlormethylundemethylcyclohexasiloxane [D5D(CH 2 Cl)], were detected in water [

In this study, distribution and accumulation of trace elements (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in water, tissues of aquatic organisms (e.g. fishes: Oreochromis niloticus, Platycephalus indicus, Clupanodon punctatus; crabs: Charybdis japonica, Portunus sanguinolentus, and Charybdis varuegata; prawns: Litopenaeus vannamei, Metapenaeus joyneri, Penaeus japonicas, Penaeus penicillatus; mollusks: Mytilus spp., Perna spp.), and trophic transfer in food web were investigated in Yundang Lagoon at Xiamen in China. Most of the studied metals such as Cr, Mn, Ni, Cu, Cd, and Pb were biodiluted in the food web except As which was biomagnified in the food web. Moreover, the target hazard quotient and total target hazard quotient risk values were higher than threshold limit values indicating that non-carcinogenic health risk to the inhabitants due to consumption of aquatic organisms. [ABSTRACT FROM AUTHOR]

Chlorinated paraffins (CPs), a class of persistent, toxic, and bioaccumulated compounds, have received increasing attention for their environmental occurrence and ecological and human health risks worldwide in the past decades. Understanding the environmental behavior and fate of CPs faces a huge challenge owing to the extremely complex CP congeners. Consequently, the aims of the present study are to summarize and integrate the bioaccumulation and biotransformation of CPs, including the occurrence of CPs in biota, tissue distribution, biomagnification, and trophic transfer, and biotransformation of CPs in plants, invertebrates, and vertebrates in detail. Biota samples collected in China showed higher CP concentrations than other regions, which is consistent with their huge production and usage. The lipid content is the major factor that determines the physical burden of CPs in tissues or organs. Regarding the bioaccumulation of CPs and their influence factors, inconsistent results were obtained. Biotransformation is an important reason for this variable. Some CP congeners are readily biodegradable in plants, animals, and microorganisms. Hydroxylation, dechlorination, chlorine rearrangement, and carbon chain decomposition are potential biotransformation pathways for the CP congeners. Knowledge of the influence of chain length, chlorination degree, constitution, and stereochemistry on the tissue distribution, bioaccumulation, and biotransformation is still scarce. [ABSTRACT FROM AUTHOR]

Previous studies have mainly focused on cadmium (Cd) contamination in conventional rice monocultures, and no research on rice-crayfish coculture has been reported. In this study, a Cd-contaminated (0–30 mg kg−1) rice-crayfish co-culture system was established by adding exogenous Cd. The results showed that the Cd concentration in each tissue of rice and each organ of crayfish increased with increasing soil Cd concentration. Specifically, the Cd concentration in each rice tissue was as follows: root > stem > leaf ≈ panicle > grain > brown rice, and the jointing and heading stages were critical periods for the rapid enrichment of Cd in the aboveground tissues of rice. The Cd concentration in each organ of crayfish was as follows: hepatopancreas > gut > gill ≈ exoskeleton > abdominal muscle. Cd was gradually enriched in the abdominal muscle after 30 days of coculture between crayfish and rice. Pearson's correlation analysis showed that the soil's total Cd concentration, available Cd concentration, and water Cd concentration were positively correlated with Cd content in various tissues of rice and various organs of crayfish, whereas EC and TDS in water were markedly related to rice stems, leaves, stalks, and small crayfish. According to the maximum limit of Cd in grain (0.2 mg kg−1) and crustacean aquatic products (0.5 mg kg−1) in China, the safe threshold of soil Cd for rice and crayfish under the rice-crayfish coculture system is 3.67 and 14.62 mg kg−1, respectively. Therefore, when the soil Cd concentration in the rice-crayfish coculture system exceeds 3.67 mg kg−1, the safety risk to humans through the consumption of food from this coculture system will increase. This study provides a theoretical basis for safe food production in a rice-crayfish coculture system using the established Cd pollution model. [ABSTRACT FROM AUTHOR]

Polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/Fs) in various foods continuously concern the public. Pork and its byproducts, especially from Yorkshire pigs, are the largest meat food consumed by the general population in China. This study aims to investigate the distribution of PCDD/Fs in different tissues of Yorkshire pigs to understand their bioaccumulation. Yorkshire pigs were fed a known amount of PCDD/Fs through fly ash. PCDD/Fs were determined by isotope dilution method with a gas chromatography‐high resolution mass spectrometer. The liver had the highest concentration levels (2041.33 pg/g lipid) and toxic equivalents values (69.14 pg/g lipid), followed by the spleen and lung, and the lowest ones in the brain. The liver also had the highest bioaccumulation of PCDD/Fs, and this level was considerably higher than that of other tissues. This study showed a strong accumulation capacity of the liver for polychlorinated dibenzo‐p‐dioxins and dibenzofurans under short‐term exposure conditions, suggesting that the liver is a more sensitive tissue for monitoring PCDD/Fs in food safety risk monitoring. Practical Application: This paper may help the consumer in making food choices to minimize the exposure risk to Polychlorinated dibenzo‐p‐dioxins and dibenzofurans. [ABSTRACT FROM AUTHOR]

Excessive accumulation of heavy metal(loid)s in agricultural environment usually originates from anthropogenic activities. Both large diversities of emission sources and complexity of plant accumulation challenge the understanding of the site-specific effects of emission sources on heavy metal(loid)s in wheat grains. Herein, both soil samples and wheat grain samples (n = 80) were collected from the farmland of Jiyuan City, China. Soil and grain burdens of heavy metal(loid)s were determined by inductively coupled plasma mass spectrometry (ICP-MS) and/or X-ray fluorescence spectrometry (XRF). The quotients (Q) were developed to indicate relative impacts of industrial plants and traffic to soil sites. Principal component analysis-absolute principal component scores-multivariate linear regression (PCA-APCS-MLR) analysis was conducted to reveal the source contributions to heavy metal(loid)s in grains, considering Q values, soil, and wheat grain data. Results showed that contributions of main sources and factors drastically varied with soil sites, and usually overlapped to different extents. For grain Cd and grain Pb, natural soil silicate (0.066/0.104 mg/kg) and iron-bearing minerals (− 0.044/ − 0.174 mg/kg) contributed to high extents, while metal smelting activities (0.018/0.019 mg/kg) and agronomic activities (− 0.017/ − 0.019 mg/kg) unexpectedly posed low or moderate contributions. The pH-mediated availability of soil Cd (0.035 mg/kg) and the sand-dust weather (0.028 mg/kg) also made considerable contributions to grain Cd. For grain As, both natural soil iron-bearing (− 0.048 mg/kg) and silicate minerals (− 0.013 mg/kg) made negative contributions. The results benefit to the decision-making of pollution remediation of farmland soils in the regional scales. [ABSTRACT FROM AUTHOR]

Pharmaceutically active compounds (PhACs) are recognized as posing health risks to aquatic ecosystems. The occurrence characteristics and ecological effects of 15 PhACs were investigated in the multiphase media of Yangtze River (Nanjing area, China) during wet and dry seasons. All 15 PhACs were detected in the traditionally dissolved phase, suspended particulate matter, sediment and fish, with total concentrations of PhACs (ΣPhACs) of 64.75–366.20 ng/L, 18.50–69.40 ng/g, 3.29–23.30 ng/g and 0.00–176.44 ng/g, respectively. Ibuprofen (IPF), roxithromycin (ROX) and caffeine (CFI) were the dominant PhACs in all of the environmental media. As the main carrier for PhACs, the colloids contributed 8.60%− 77.04% of PhACs in the traditionally dissolved phase, and distribution coefficients (log K col =6.38–7.95) of PhACs in colloidal phase were significantly higher than those in SPM and sediment. The bioaccumulation potential of ΣPhACs in the wild fish tissues was generally in order as follows: brain > liver > kidney > gill > blood > intestines > muscle > bile, which was positively correlated with their log K ow. The concentrations of CFI, ROX and IPF in the muscle, gill and liver can be predicted by their log K ow and pollution levels in the blood, and the concentrations of PhACs in the muscle of benthic fish were much higher than those in pelagic fish. The bioaccumulation factors of ROX, fluoxetine and bezafibrate in intestines, brain and blood showed strong enrichment capacity (>5000). In the risk assessment, the acute risk level of PhACs to aquatic organisms decreases gradually with the trophic level, while the trend of chronic risk was the opposite. The chronic mixture risk of PhACs to fish was > 1 at all sampling sites, 59.79% of mixed risk quotient were provided by clofibric acid, diclofenac, erythromycin and ketoconazole. These results indicated that PhAC can cause harmful health effects to sensitive organisms both individually and mixedly. [Display omitted] [ABSTRACT FROM AUTHOR]

Hexabromocyclododecane (HBCD) was listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants for its persistence, bioaccumulation and toxicity, and pose significant adverse effects on natural environments and human health. HBCDs are ubiquitously found in marine environments worldwide and can be biomagnified in marine organisms with a high trophic level. In the present study, we reviewed the available data on contamination of HBCDs in the marine biota from China, including mollusks, crustaceans, fish and mammals. Bioaccumulation and biomagnification of HBCDs in the marine food web were summarized as well. This study also prospected the future research of HBCDs, including the transport and fluxes of HBCDs to and within the marine environment, the biomagnification of HBCDs in different ecosystems, and the metabolism of HBCDs in different marine species. [ABSTRACT FROM AUTHOR]

Herein, we investigated the trophic transfer of mercury (Hg) through food chains in different habitats (namely aquatic, riparian, and terrestrial) through bulk stable isotope analysis of nitrogen (δ15N bulk) and compound-specific isotope analysis of nitrogen in amino acids (δ15N AA) using bird feathers and their potential food sources from a Hg-contaminated site in southwest China. Results showed similar δ15N phe for water birds (4.7 ± 2.6 ‰) and aquatic food sources (5.2 ± 2.1 ‰) and for land-based food sources (10.1 ± 0.4 ‰) and terrestrial birds (11.6 ± 3.0 ‰), verifying δ15N phe as a potential discriminant indicator for different food sources. The trophic positions (TPs) of most organisms based on δ15N bulk (TP bulk) tended to overestimate compared with those based on δ15N AA (TP AA), especially for predators (such as kingfisher: ΔTP = 1.3). Additionally, significant differences were observed in the aquatic, riparian, and terrestrial food webs between trophic magnification slope (TMS) bulk and TMS AA (p < 0.05). The trophic magnification factor (TMF) AA-multiple based on multiple-AAs in three food webs were higher than the TMF AA and TMF bulk , probably because of the greater variation of δ15N baseline , complex food sources or the notably different in individual organisms. Altogether, our results improve the understanding of Hg trophic transfer in aquatic, riparian, and terrestrial food webs. [Display omitted] • δ15N phe can distinguish food sources among different trophic organisms. • Compared with the TP AA and TP multiple , the TP bulk may overestimate TP values of most organisms. • The more reliable TMF AA-mutiple-MeHg in the aquatic, riparian and terrestrial food webs were nearly 1.48, 1.48 and 4.07 (5.76, 4.17 and 11.21) times higher than those of TMF AA (TMF bulk), respectively. [ABSTRACT FROM AUTHOR]

Microplastics pose a threat to marine environments through their physical presence and as vectors of chemical pollutants. However, the impact of microplastics on the accumulation and human health risk of chemical pollutants in marine organisms remains largely unknown. In this study, we investigated the microplastics and polycyclic aromatic hydrocarbons (PAHs) pollution in marine organisms from Sanggou Bay and analyzed their correlations. Results showed that microplastic and PAHs concentration ranged from 1.23 ± 0.23 to 5.77 ± 1.10 items/g, from 6.98 ± 0.45 to 15.07 ± 1.25 μg/kg, respectively. The microplastic abundance, particularly of fibers, transparent and color plastic debris, correlates strongly with PAH contents, indicating that microplastics increase the bioaccumulation of PAHs and microplastics with these characteristics have a significant vector effect on PAHs. Although consuming seafood from Sanggou Bay induce no carcinogenic risk from PAHs, the presence of microplastics in organisms can significantly increases incremental lifetime cancer risk of PAHs. Thus, microplastics can serve as transport vectors for PAHs with implications for the potential health risks to human through consumption. This study provides new insight into the risks of microplastics in marine environments. [Display omitted] • The microplastic and PAHs pollution in organisms from Sanggou Bay were investigated. • Notable correlation were observed between microplastic and PAHs contents in organisms. • The PAHs in organisms pose no cancer risk to humans based on the ILCR analysis. • The microplastic characteristics in organisms affect human health risks of PAHs. [ABSTRACT FROM AUTHOR]

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Hangzhou Bay is facing severe anthropogenic perturbation because of its geographic position. We studied species-specific bioaccumulation of metals in commercially important fishes and shellfishes, and calculated the potential human health hazards through their consumption, which has not been reported earlier from this area. The hierarchy of metal concentration in organisms was in the decreasing order of Zn (10.32 ± 7.13) > Cu (2.40 ± 2.66) > As (0.42 ± 0.26) > Cr (0.11 ± 0.08) > Cd (0.07 ± 0.07) > Pb (0.05 ± 0.02) > Hg (0.012 ± 0.009). Except for Cd and As concentrations in fishes, metal concentrations have not exceeded the national and international guideline values. P. laevis and P. trituberculatus were the most bioaccumulative of the species studied. According to the non-carcinogenic risk assessment, children were more susceptible to metal contamination than adults. The carcinogenic risk (CR) values indicated that children were likely to experience carcinogenic threats for taking cancer-causing agents As and Cd through fish consumption. In terms of organisms, intake of two crab species, P. trituberculatus and E. sinensis, as well as the oyster species P. laevis, could be detrimental to consumers. [ABSTRACT FROM AUTHOR]

The transfer and fate of methylmercury (MeHg) in typical components, such as sediment, sediment-inhabiting animals, pelagic fish, and three large waterfowls, namely, red-crowned crane (Grus japonensis), mallard (Anas platyrhynchos), and oriental stork (Ciconia boyciana), of the ecosystem in China's Zhalong Wetland were examined using equivalence-based mass balance model. The biomagnification degree of MeHg increased on the species at the high trophic level of the system. Hence, elevated MeHg concentration (3.2 μg g−1, dry weight) was detected in the endangered G. japonensis. The accumulation of the organometal generally followed the decreasing order of oriental stork (carnivore) > mallard (omnivore) > red-crowned crane (omnivore). The predicted results of MeHg at each node of the food web were generally in accordance with the measured values (F = 0.09, P = 0.78), implying that the model is suitable for the prediction of MeHg fate in the inland aquatic system. According to the model, the respiration for the species at low trophic strata was the key input source of MeHg, but ingestion played an important role for MeHg intake in the species at the high trophic position in the food web. Metabolism was a crucial pathway of MeHg loss for the top predators in the ecosystem. [ABSTRACT FROM AUTHOR]

Heavy metal (Cu, Mn, Zn, Pb, and Cd) concentrations were measured in the leaves of Sabina chinensis and Platycladus orientalis collected from urban, suburban, and rural sites in Tianjin, China. Photosynthetic pigment contents, reactive oxygen species content, malondialdehyde (MDA) content and antioxidant enzyme activity were investigated, providing physiological response parameters. Our comparison of the sites revealed that urbanization significantly influenced the heavy metal concentrations in both plant leaves. At the rural site, both plant leaves exhibited the lowest heavy metal accumulation. The highest Cu, Mn, and Zn concentrations were found in S. chinensis leaves from the urban site; the highest Pb and Cd concentrations were found in P. orientalis leaves from the urban site. These results indicate that the urban site contained larger heavy metal concentrations in the plant leaves that may reflect the anthropogenic emission gradient. It is also found that S. chinensis may be used to monitor airborne heavy metal pollution because it is highly quick response to heavy metals, while P. orientalis may be used for mitigation due to its high resistance. The results of this study can contribute to the development of monitoring and environmental management plans by providing information on sensitive and resistant tree species for city greening in North China. [Display omitted] [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the distribution of cadmium (Cd) accumulation in tobacco and identify the relationship between soil properties and plant Cd concentration. Forty soil and tobacco samples were collected from the Sichuan Basin, China (Panzhihua, Luzhou, Guangyuan and Yibin). The results showed the highest Cd in soil (2.94 mg kg−1) was in Yibin. Correspondingly, Cd concentrations in tobacco from Yibin were significantly higher than those from the other regions. The Cd concentrations in tobacco from Yibin, Luzhou, Guangyuan and Panzhihua were from 2.22 to 13.14, 0.59 to 2.12, 0.26 to 0.61, 0.10 to 0.37 mg kg−1, respectively. The Cd concentrations in leaves were higher than those in stems and roots. The highest Cd concentrations were in lower leaves, between 0.36 and 13.14 mg kg−1. In Yibin, the Cd in lower leaves nearly exceeded 10 mg kg−1 and the ratio of the Cd tobacco and soil concentrations (the bioconcentration factor, BCF) was 9.41. Path analysis showed soil pH and cation exchange capacity (CEC) were the most significant properties exhibiting direct effects on Cd accumulation. Stepwise multiple linear regression showed that soil Cd, pH, CEC and organic carbon (OC) were the major factors controlling Cd bioavailability to tobacco leaves, explaining more than 94.0% of the variance. The results are useful in predicting the transfer of Cd from soil to tobacco. [ABSTRACT FROM AUTHOR]

Obesity is a chronic syndrome whose main characteristic is the excessive accumulation of adipose tissue in different regions of the body. This accumulation causes physiological and metabolic changes that can lead to damage to the health and quality of life of individuals with this syndrome. Traditional Chinese medicine is an ancient therapy, with records of its appearance before Christ, originating in China. It has enormous efficacy in the treatment of several syndromes, including obesity. Such therapy is based on the use of the concepts of organs and viscera, yin yang, channels and collaterals and Qi for the diagnosis and treatment of the referred energy syndromes. TCM acts on obesity because it has an antiinflammatory, sedative and neuroendocrine stimulating effect. Among its therapies is auriculotherapy, a technique that treats the body as a whole using reflex points located in the ear. In this perspective, this research aimed to review the literature looking for original articles in which auriculotherapy was used as an alternative to aid in weight reduction in obese individuals in order to assess the effectiveness of the therapy as well as to identify the possible mechanisms by which auriculotherapy influences obesity reduction. It is possible to observe great results with regard to the reduction of anthropometric indices of obese individuals, with a greater adhesion of the female public in the practice of therapy, concluding that the technique is shown as an important aid tool in the treatment of obesity. [ABSTRACT FROM AUTHOR]

Metal contamination from base metal sulphide mines is a major environmental challenge that poses many ecological and health risks. We examined the metal concentrations in the Dabaoshan mine in South China in water, sediments, and aquatic organisms and their specific characteristics (i.e. size, body tissue, species, and habitat) along the Hengshi and Wengjiang River courses to assess acid mine drainage remediation efforts. Metal concentrations of arsenic, cadmium, chromium, copper, lead, nickel, thallium, and zinc were examined in tissues (i.e. gills, intestines, and muscles) of 17 freshwater species of fish, shrimps, and crabs. Metals in tissues followed the trend: intestines > gills > muscles; nearly all intestine samples exceeded the safe limits of metals analysed in this study. There is a positive correlation between distance from the mine and metal concentrations related to the flow of surface water and the habitat of aquatic organisms. The concentrations of arsenic, copper, and zinc were the highest in aquatic organisms, and the distribution was influenced by physical (distance from mine, currents, and seasonality), chemical (pH and competing ions), and biological (species, habitat, and predator–prey relation) factors. Large demersal fish and benthic fauna had higher concentrations of metals. Bioaccumulation and biomagnification of metals, as well as the high metal pollution index and target hazard quotient (arsenic, cadmium, copper, lead, thallium, and zinc), occurred in bottom feeders (C. aumtus, X. argentea) and fish belonging to higher trophic levels (P. fulvidraco, O. mossambicus). Lead and cadmium indicated the highest level of biomagnification from prey to predator. Health risks exist from the dietary intake of common aquatic species such as tilapia and carp besides crustaceans due to high arsenic, cadmium, lead, and thallium levels. Further reduction of metals is necessary to improve the effects of acid mine drainage in the catchment. [ABSTRACT FROM AUTHOR]

Pollution resulting from toxic trace elements is an increasing concern around the world especially in developing countries such as China. Rapid industrialisation, urbanisation and agricultural development are the dominant sources of anthropogenic contamination contributed to an increased potential toxicity of trace elements in the irrigation water–soil–food chain. Xin Jiang in China is a reserved cultivated land development area that could provide the most extensive strategic support for food production and arable land security in China. Thus, it is crucial to investigate the bioaccumulation and translocation of trace elements in order to assess the ecological and human health risks in the traditional oasis system of the agricultural areas in Bay Cheng County, Xin Jiang. This study analysed the levels of trace elements in different layers of the soil, the irrigation water and the wheat plants, and the relationships among them. The results indicated that cadmium (Cd) and chromium (Cr) were the primary pollutants in soils and wheats respectively, and they fell into the serious pollution category. However, no trace elements over the pollution limits were detected in irrigation water. The maximum values of trace elements appeared in the soil layers at 5–10 cm and 10–15 cm. The pollution levels of trace elements in the soil layers were found at 0–5 cm and 0–20 cm, which were higher than those at 20–80 cm. In wheat, high amounts of absorption for Se, Cr, Zn and Cu, but low for Pb were detected in different parts of a plant. The roots of wheats were more eco-toxic to Cd, Co and Pb than other tissues, indicating that roots were more effective at absorbing Cd, Co and Pb, as these metals are usually toxic in the soil. Se, Cu and Zn showed a higher ability of being transferred from soils to the edible parts of crops. The bio-transfer factors of Zn, Mo, Cu, Mg and Mn were considerably higher than those of other elements. The average cancer risk of As, Cd, Co, Ni and TCR in wheat grains exceeded the safety reference limit (1 × 10−4). For the exposed population, Cr in wheat was the major contributor to total cancer risk. The average values of HQ of Cr, Mn and As, and total non-cancer risk index exceeded the corresponding effective safe reference doses (HQ > 1). [ABSTRACT FROM AUTHOR]

As a class of synthetic sulfur drugs, sulfonamides (SAs) have been used to treat diseases and promote organism growth. Different concentrations of SAs have been detected in the water environment, which has threatened the ecological environment. In this study, the contamination of 9 SAs in water, sediments, and 8 fish species from the Hangbu-Fengle River, China, were analyzed using UPLC-MS/MS. The total SA concentrations in surface water, sediments, and fish were ND-5.064 ng/L, ND-5.052 ng/g dry weight (d.w.), and ND-1.42 ng/g wet weight (w.w.), respectively. The major compounds were sulfadiazine (SDZ), sulfamerazine (SMZ), and sulfamethoxazole (SMX) in water and fish. The SA levels of in fish from different habitat preferences revealed a spatial difference, with the order of demersal species > pelagic species. Moreover, the SA concentrations were affected by trophic guilds, indicating their decrease in the order of piscivorous fish > omnivorous fish > planktivorous fish > herbivorous fish. The obtained bioaccumulation factors showed that SMZ and SMX have strong bioenrichments in Ophiocephalus argus Cantor and Pelteobagrus fulvidraco. The risk assessment indicated that SAs did not pose significant health threats to the organisms. This research is the first report of SA contamination in the Hangbu-Fenle River, which can provide an important scientific basis for their pollution prevention and ecological risk assessment in the aquatic environment. [ABSTRACT FROM AUTHOR]

Purpose: Compared with deep oligotrophic waters, the distribution and geochemical processes of polycyclic aromatic hydrocarbons (PAHs) in shallow eutrophic waters are more complicated. The fourth largest freshwater lake in China (Lake Hongze) was taken as an example to study distribution, sources, bioaccumulation, and air–water exchange of PAHs in shallow eutrophic waters. Materials and methods: Eighty samples of surface sediments, air, water, and plankton were collected simultaneously from 15 sampling sites in November 2018. PAHs were extracted, concentrated, and analyzed using GC–MS. Results and discussion: Average concentrations of ∑PAH16 in the surface sediments, atmosphere, water, phytoplankton, zooplankton, and suspended particle matter were 511 ± 212 ng g−1, 119 ng m−3, 232 ± 91.2 ng L−1, 12,500 ± 70,000 ng g−1, 102,000 ± 83,600 ng g−1, and 35,100 ± 24,700 ng g−1. Log BCF of PAHs in phytoplankton ranged from 6.7 ± 7.8 to 16.0 ± 4.4. Log BAF of PAHs in zooplankton ranged from 8.2 ± 8.1 to 16.8 ± 3.9. Log BMF of PAHs from phytoplankton to zooplankton varied from − 0.25 ± 0.39 to 0.25 ± 0.55. Conclusions: Combustion of petroleum and coal was the main source for the PAHs in the surface sediments of Lake Hongze. Concentrations of PAHs in phytoplankton and zooplankton were negatively correlated to the trophic level index. Bioaccumulation of PAHs by plankton was observed. No biomagnification occurred from phytoplankton to zooplankton for most PAHs during this sampling period. The net air–water flux of low molecular weight PAHs was from water to air. The net air–water flux of high molecular weight PAHs was from air to water. [ABSTRACT FROM AUTHOR]

Metal contamination in fishery water may pose a serious threat to aquatic products and human health. In this study, the contents of seven trace metals were assessed in water, sediment, and ten commercially important species (seven fish and three crustaceans) with different trophic guilds, habitat preferences, and motility, collected from the Zhoushan Fishery, northwest East China Sea. In general, the results showed that the concentrations of trace metals in water and sediment were lower than the safety thresholds set by the National Seawater Quality Standard of China and the sediment quality guidelines, except for Cu, As, and Cr in sediment. The high metal concentrations were spatially distributed in the west of the Zhoushan Fishery, which is probably due to the chemical pollution generated from many large international ports and chemical industries in Hangzhou Bay. The metal concentrations in the species were lower than the legislation thresholds established by the Commission Regulation and China National Standard, except for Cd in two crustacean species. However, a health risk assessment indicated that the consumption of the analyzed seafood is safe. However, there is a potential risk to local consumers who prefer crustaceans. From a species-specific bioaccumulation point of view, species in high trophic guilds, benthivores, species with low motility, or those living near the sediment have been found to be most likely to accumulate metals. Our findings could contribute to the understanding of the accumulation tendencies of metals in species of different trophic guilds with varying habitat preferences and motility and provide valuable data to environmental and seafood safety managers. [ABSTRACT FROM AUTHOR]

Trace metal contamination in water and bioaccumulation in aquatic organisms are human health risks of increasing concern. However, the bioaccumulation of trace metals in the organs of the mussel Cristaria plicata in Dongting Lake, China and the human health risks of mussel consumption are largely unknown. We investigated the concentrations of 15 trace metals and metalloids in surface water, sediments, and C. plicata organs (foot, gill, mantle, and visceral mass) and quantified the bioaccumulation and human health risk of these trace metals in specimens collected from Dongting Lake. The concentrations of most metals in surface water exceeded previously published background values. In contrast, the concentrations of most metals in sediments showed a decreasing trend. Overall, the metal concentrations in the gill and visceral masses of C. plicata were higher than those in the foot and mantle, and higher bioaccumulation capacities were observed for essential metals than for nonessential metals. The mean concentrations of the trace elements Zn, Pb, Cd, As, Cu, and Cr in C. plicata foot samples were lower than the threshold values established by international and Chinese organizations. The estimated daily intake (EDI) values of the essential metal Mn in C. plicata foot was higher than the recommended tolerable daily intake (TDI) values for juveniles. Only Mn for juveniles and As for both juveniles and adults may pose noncarcinogenic health risks through foot consumption. The hazard index (HI) values for adults and juveniles were higher than 1, suggesting significant risks of noncarcinogenic effects to humans by exposure to multiple metals. [Display omitted] [ABSTRACT FROM AUTHOR]

Understanding the metal concentrations in oysters is important because of its relevance to human health and biomonitoring. However, metal concentrations in oysters are highly variable in nature and not well explained by metal exposure. This study examined the metal contamination in farm oysters Crassostrea hongkongensis grown in Qinzhou Bay, south China. Cadmium (Cd), zinc (Zn), nickel (Ni), and copper (Cu) concentrations in the oysters varied between 7.9 and 72.2, 282–17003, 0.37–47.7 and 37–4012 μg g−1, respectively, showing large metal variability among different individuals. Oyster metal concentrations decreased with increasing body size and significantly higher levels were observed in wet season. Low salinity and slower oyster growth due to inferior growth conditions could be responsible for the elevated metal concentrations in the wet season. Biokinetic modeling showed that the coupling of ingestion rate and growth can cause 2.8–4.2 folds differences in the oyster Cd and Zn concentrations, respectively, suggesting the significant role of oyster bioenergetics in contributing to the metal variability. Modeling data revealed that Cd and Zn concentrations in oyster tissues reach maximum levels when oysters have their lowest growth efficiency. This suggests that any factors influencing the energy budget in oysters could simultaneously alter their metal concentrations, which might be the reason why oyster metal concentrations are so variable in the natural environment. • Remarkable variations of metal concentrations were observed in estuarine Crassostrea hongkongensis. • Cadmium, zinc and copper concentrations in the oysters were more variable than nickel. • The coupling of ingestion rate and growth rate produces significant among-individual variability. • The variations of metal concentrations are driven by gross growth efficiency in oysters. [ABSTRACT FROM AUTHOR]

Phthalate esters (PAEs) have received widespread attentions due to their ubiquity in various kinds of matrices and potential biotoxicity. This study systematically compared the concentrations, bioaccumulation, trophodynamics and health risk of PAEs in 25 species (n = 225) collected from a marine (Bohai Bay, BHB) and freshwater environment (Songhua River, SHR), China. Results showed that di-(2-ethylhexyl) phthalate and di-n-butyl phthalate were the predominant PAEs in the organisms from the two aquatic environments. The total concentrations of 6 PAEs in algae and fish from SHR were significantly higher than those from BHB. Two food webs were constructed in BHB and SHR based on the abundance of 15N in the organisms. All the PAEs except dimethyl phthalate exhibited trophic dilution with the trophic magnification factors less than 1. Moreover, an obvious biodilution of PAEs was observed in marine food web compared to freshwater food web. A low health risk of PAEs was found in organisms from both BHB and SHR. However, di-(2-ethylhexyl) phthalate exhibited a potential carcinogenic risk by consumption of some benthos in BHB and fish in SHR. This study provides a valuable perspective for understanding the trophodynamics and health risk of PAEs in marine and freshwater environments. [Display omitted] • Concentrations of 6 PAEs vary greatly among the 25 species. • The values of log K ow are positively correlated with log BAF of PAEs. • Two food webs are constructed based on the values of δ15N in 25 species. • Five PAEs exhibit biodilution in both marine and freshwater food webs. • DEHP may pose a carcinogenic risk by consumption of some benthos and fish. [ABSTRACT FROM AUTHOR]

The work investigated the concentration of perfluorinated compounds (PFCs) in surface water, sediments and aquatic plants of Nansi Lake, China. The total concentration of 12 PFCs was in the range of 34.07–153.39 ng/L in surface water. The short-chain PFCs were dominant PFC homologs, and the concentration of PFOA was higher than that of PFOS in water samples. The total concentration of 12 PFCs was in the range of 0.63–1.62 ng/g (dry weight, DW) in the sediments. There were more long-chain PFCs (PFOA and PFOS) than short-chain PFCs in sediments, with no apparent connection according to the concentration of PFCs in water and sediments. Moreover, the bioaccumulation factors (BAF) indicated the aquatic plants had significant absorption for long-chain PFCs (PFOA and PFOS), especially PFOS. The log BAF value of Ceratophyllum demersum Linn for PFOS was the highest in all aquatic plants. Risk assessment indicated that the water environment of Nansi Lake was at a safe level. [ABSTRACT FROM AUTHOR]

Cadmium has become the foremost inorganic pollutant in farmland in China. It is widely accumulated in karst areas in southwest China, especially in Guangxi Province. In this study, vertical soil profiles, rice grains and corresponding root-soil samples were collected in Guangxi. The Cd contents of soil and rice grain samples and several soil properties, including organic matter, Fe2O3, Al2O3, CaO, MgO, SiO2 contents and pH were tested. Meanwhile, sequential extraction procedure were used to analysis the chemical fractions of Cd in root-soil samples. Based on the measured data, influencing factors on bioaccumulation of Cd and its contamination risk in study area were discussed. The results indicate that the bioaccumulation and mobility of Cd from soil to rice grain are restrained by high soil pH, high contents of organic matter, clay mineral and carbonate. Guangxi has strong development of karst landform, with the continuous process of soil formation, the activity of Cd in the soils in such areas will gradually become stable. In general, the environmental risk of soil cadmium contamination in karst areas of Guangxi is relatively low. But preventing soil acidification is the significant measure to prevent the environmental risk of it. [ABSTRACT FROM AUTHOR]

Cd, Cr, Cu, Pb, and Zn concentrations were measured in oysters (C. gigas), plankton, and seawater during spring, summer, and autumn in Liaodong Bay (Bohai Sea, China) to elucidate the effects of season, region, and oyster size on metal bioaccumulation in oysters. Metal concentrations were quantified via atomic absorption spectrophotometry. Our study determined that metal concentrations in oysters, plankton, and seawater were the highest in summer, whereas the lowest levels occurred in autumn. Regarding oyster sizes, the highest Pb levels occurred in C3-sized oysters (> 5-cm length), whereas the highest Cd, Cr, Cu, and Zn levels occurred in C2 (3–5-cm length) oysters. In contrast, the lowest Cu and Pb levels occurred in C1 (< 3-cm length) oysters, whereas the lowest mean Cd, Cr, and Zn concentrations were observed in C3 oysters. Significant differences in trace metal concentrations in the three sample types were observed in all sampling sites. [ABSTRACT FROM AUTHOR]

To quantitatively assess heavy metal accumulation and potential ecological and human health risks as well as analyze the sources of metals in a typical soil-rice system located on the southeast coast of China, 120 topsoil samples and corresponding rice grain samples were collected across the study area. The concentrations of As, Cd, Pb, Cr, Hg, Zn, Cu, and Ni were analyzed. The results revealed that Hg, Cd, and Cu were the main pollutants in soils. Besides, according to geo-accumulation value of Hg, 18.3% of samples were at or above moderate contamination levels. Additionally, the soil was in moderate ecological risk from combined heavy metal pollution, and 49.7% and 27.0% of this risk could be attributed to Hg and Cd pollution, respectively, due to their high toxic-response factors. For the rice samples, Cd content showed the highest biological accumulation coefficient value (40.8%) in rice grains and was slightly greater than its maximum allowable value (MAV) (0.2 mg/kg) in 7.5% of samples, whereas the other metals were all lower than their corresponding MAVs. Heavy metal exposure (especially As exposure) via rice consumption causes significant carcinogenic and non-carcinogenic risks to adults, and non-carcinogenic risk to children, while the carcinogenic risk to children was at tolerable level. Greater rice consumption might be responsible for the greater health risk to adults than children. Natural sources (loaded heavily with Cr and Ni) such as lithogenic components and soil parent materials, agricultural activities (loaded heavily with Cd, Cu, and Zn), especially excessive use of pesticides and fertilizers, and industrial activities (loaded heavily with Hg, Pb, and As) including vehicle emissions, coal combustion, and those of the textile and chemical industries were identified as the main sources. Effective regulations should be enforced to guarantee the safety of farm produce and protect ecological and human health in the study area. [ABSTRACT FROM AUTHOR]

Evaluating the bioaccumulation and health risk of heavy metals in soil-crop systems is essential in Liujiang karst regions. In the current study, the single and comprehensive uptake effects of heavy metals (i.e., Cu, Cr, Cd, As, and Zn) between rice and sugarcane and their rhizosphere soils were investigated. The estimated daily ingestion (EDI), target hazard quotient (THQ), and hazard index (HI) were estimated for health risk assessments. The results showed that the mean contents of Cu, Cr, Cd, As, and Zn in rice soils were 25.8, 168, 1.91, 20.0, and 160 mg/kg, respectively, and those in sugarcane soils were 28.8, 186, 0.44, 31.0, and 108 mg/kg. Rice soils were mainly contaminated by Cd, and Cd and Cr were the main pollutants in sugarcane soils. The average concentrations of Cu, Cr, Cd, As, and Zn in rice grains were 1.79, 0.15, 0.16, 0.11, and 12.7 mg/kg, respectively, and in sugarcanes were 0.10, 0.036, 0.022, 0.006, and 0.38 mg/kg. Both crops tended to take up Cd more effectively, and rice grains exhibited higher accumulation capacities of heavy metals in edible part than sugarcanes. Prediction models of Cd and comprehensive accumulation factors were established for rice and sugarcane, and different soil factors affect metal accumulation in crops cultivated in different types. Due to the exposure to As and Cd through rice consumption, non-carcinogenic risks are likely to occur in Liujiang residents. [ABSTRACT FROM AUTHOR]

Lichen element compositions are of a reliable tool for the biomonitoring of atmospheric element deposition. The zoning and patterned accumulation of elements in lichen thallus is one of the important factors influencing lichen element concentrations. We collected an epigenous fruticose lichen Cladonia rangiferina (CR) from a remote site of Huzhong National Natural Reserve, Heilongjiang, NE China. Fifty-five elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Gd, Ge, Hg, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Tb, Th, Ti, Tl, Tm, U, V, Y, Yb, and Zn) were measured with their differences among 3 parts (upper, middle, and lower) of the podetia compared. The aim of the present study was to examine the vertical patterns of element accumulation in CR. The results display a very low degree of atmospheric element deposition in the study site. Concentrations of most elements of limited metabolic significance generally increase from the upper to lower parts, indicating a continuous bioaccumulation of these elements with exposure time. Concentrations of some nutrients have little vertical difference among parts (Zn), and they are higher in the upper part than in the middle part (K, P, and S), or are similar between the upper and middle parts (B, Cu and Mg). These results suggest a nutrient translocation to the more biologically active young part. Our results highlight the importance of selecting the suitable parts of lichen thallus to increase the comparability of data in lichen biomonitoring studies. [ABSTRACT FROM AUTHOR]

Soil properties largely control the fate of mercury (Hg), including the synthesis of neurovirulent methylmercury (MeHg). Here, the freshwater snail (Cipangopaludina cahayensis), a snail species commonly bred in flooded farmland, was used in a test of biotoxicity exposure to explore the effects of soil components on Hg bioavailability. The results show that snails incubated on the surface of slightly Hg-polluted flooded soil (2.0 mg/kg) have MeHg concentrations of 7.9 ± 1.5 mg/kg, which greatly exceed the limit of contaminants in food in China (0.5 mg/kg). The addition of ferrous disulfide can significantly increase the MeHg concentrations in soils while reducing the concentrations of total Hg (THg) and MeHg levels in snails by 59.1% and 64.3%, respectively. Peat-derived fulvic acid has the capacity to reduce the MeHg concentrations in soils and snails by 23.8% and 33.2%, respectively, whereas it increases the dissolved Hg levels in overlying water by 104.3%. Moreover, Fe–Mn oxides and humic acid can consistently reduce THg and MeHg concentrations in snails. Overall, freshwater snails bred in Hg-polluted areas may suffer from a high risk of Hg exposure, and importantly, some soil components such as ferrous disulfide and humic acid have strong inhibitory effects on Hg bioaccumulation in snails. [ABSTRACT FROM AUTHOR]

• Metal exposure levels exhibited obvious variations between species. • Cu and Zn were the most accumulated elements. • Most trace metals declined over the last one to two decades. • Metals in the cultured organisms was far lower than those in wild marine organisms. Trace metal (Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab>shellfish>shrimp>fish. The higher metals enrichment seen in shellfish and crab species primarily attributed to their living habits and the higher sediment background values of trace metals. Endpoint bioaccumulation factor (BAF fd) was used to characterize the bioaccumulation potentials of marine organisms to trace metals, of which Cu and Zn were the most accumulated elements. The exposure of trace metals in the cultured organisms was far lower than those in wild marine organisms, which is probably due to the effect of growth dilution. Comparisons with previous studies demonstrated that the concentration profiles of most trace metals declined over the last one to two decades, except Cu, that increased indistinctively. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Fluazinam (FZN) is a dinitroaniline fungicide. To evaluate the environmental risk of FZN in aquatic environments and ascertain the potential danger to typical aquatic organisms in China, the acute toxicity of FZN to representative aquatic organisms, including Brachydanio rerio, Chlorella vulgaris Beij., Daphnia magna Straus, and Xenopus laevis, was measured, and its bioaccumulation properties in Brachydanio rerio were further investigated. The results showed that the acute toxicity of FZN to Brachydanio rerio and Xenopus laevis is extremely high, and the bioaccumulation factor BCF8d of FZN in Brachydanio rerio ranges between 2287 and 3570, implying that it has high bioaccumulation properties. FZN poses a strong environmental risk for aquatic organisms and possesses great bioaccumulation properties, which may cause pollution to aquatic environments. [ABSTRACT FROM AUTHOR]

Blechnum orientale L. is a traditional, medicinal fern found in China. To assess the characteristics of heavy metals and As accumulation, the fronds, roots, and the rooting soils of this fern were sampled from urban, suburban, and rural woodlands across Guangdong Province in southern China. The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn in both the fern and its rooting soils were separately detected by ICP-MS. Contamination levels of woodland rooting soils were also assessed using both a single pollution index and the Nemerow pollution index. Both the metal concentrations and the pollution index showed that soils from urban, suburban, and even rural woodlands were adversely contaminated by As, Cd, Hg, and Pb. Based on transfer factor, B. orientale had good translocation of As, Hg, and Mn, but poor translocation of Cd, Cr, Ni, Cu, Ni, Pb, and Zn from the roots to the fronds. This result suggests that this fern could be an excluder to latter metals. Despite the significantly higher levels of metals in the roots as compared with the fronds, the low bioaccumulation factor suggests that this fern has a weak capacity for metal accumulation. [ABSTRACT FROM AUTHOR]

The concentration of heavy metals (HMs) in plants is determined by the background values in soil and/or the expression of genes related to HM metabolism. To determine if the bioaccumulation of HMs in Ammopiptanthus mongolicus, an evergreen desert shrub commonly used as a traditional medicine, is related to environmental background and/or tissue (organ) specific, the HM concentrations (As, Cd, Cr, Cu, Hg, Pb, Ni, and Zn) in the soil, roots, stems, and leaves of A. mongolicus in the desert of northwestern China were measured. Efficiencies of bioconcentration, bioaccumulation, and translocation to different portions of the plant were calculated. A linear mixed-effects model was used to test the effects of environmental background and tissue specificity on bioaccumulation. The results showed that most HMs did not exceed the pollution threshold in the soil samples, and the accumulation in plants did not meet the standard of worldwide averages. The phytoaccumulation of HMs was independent of the background concentration in soil but was related to plant tissues, which reflects the low mobility of HMs in the desert, and suggesting that the phytoaccumulation is related to the metabolic capacity and/or differential expression of HM-related genes in tissues of A. mongolicus. The high translocation efficiency of mercury from the underground portion to the leaves makes A. mongolicus a potential phytoremediator for mercury contamination. However, the removal efficiency in high-dose contamination soil still needs to be further examined. This study suggests that the desert environment may lack appropriate microorganisms to decompose immobile HMs effectively. In addition, when using A. mongolicus as a medicinal plant, special attention should be paid to the accumulation of HMs in different tissues, even if they have not reached the risk threshold. [ABSTRACT FROM AUTHOR]

Concentrations of heavy metals (HM) in water, bottom sediments and soft tissues of native bivalves were determined to indicate the level of anthropogenic pressure on the Songhua River near Harbin, China. It was found that concentrations of six HM (Cd, Cr, Cu, Mn, Pb, Zn) ranged from 0.001 to 0.007 (mg/L) in water and from 0.07 to 5617.13 (mg/kg) in bottom sediments. At the study site of the river exposed to severe anthropogenic pollution, different bivalves exhibited different rates of HM accumulation in their soft tissues. The bioconcentration factors (BCF) were calculated for each metal and proved to be significantly different in the tissues studied (gills and hepatopancreas). The obtained data confirmed the existence of inter-species differences in metal accumulation in tissues of the native bivalves. This approach can be useful both in comparative physiological studies of the Bivalvia and in choosing optimal indicator organisms to assess anthropogenic pollution of natural waters of Northern China and the Russian Far East. [ABSTRACT FROM AUTHOR]