Microplastics (MPs) are ubiquitous environmental contaminants that exerting multiple toxicological effects. Most studies have focused primarily on the models of unaged MPs and lack environmental relevance. The generation and toxicity of environmentally persistent free radicals (EPFRs) on photoaging MPs from disposable plastic cups (DPC-MPs) have not been well studied. Here, the formation of EPFRs on photoaged DPC-MPs and their toxic effects in nematodes were investigated. UV irradiation generated EPFRs, which influenced the characterization of DPC-MPs. Exposure to photoaged DPC-MPs at environmentally relevant concentrations (100-1000 mu g/L) reduced the locomotion behavior, body length, and brood size. The Reactive oxygen species (ROS) production, lipofuscin accumulation, malondialdehyde (MDA), and 8-hydroxy-2 '-deoxyguanosine (8-OHdG) levels were increased along with the downregulation of the expression levels of associated genes, such as clk-1, clt-1, and gst4,in nematodes. Moreover, the toxicity and oxidative stress response of nematodes were significantly inhibited due to N-acetyl-l-cysteine (NAC). Pearson's correlation analysis revealed that the oxidative stress was significantly associated with adverse physiological effects. Therefore, EPFRs on photoaged DPC-MPs cause toxicity in nematodes, and oxidative stress is important for regulating toxicity. This study offers novel insights into the potential risks of DPC-MPs under UV irradiation, highlighting the need to consider the role of EPFRs in toxicity assessments of DPC-MPs.

Tire wear particles (TWP) are a prevalent form of microplastics (MPs) extensively distributed in the environment, raising concerns about their environmental behaviors and risks. However, knowledge regarding the properties and toxicity of these particles at environmentally relevant concentrations, specifically regarding the role of environmentally persistent free radicals (EPFRs) generated during TWP photoaging, remains limited. In this study, the evolution of EPFRs on TWP under different photoaging times and their adverse effects on Caenorhabditis elegans were systematically investigated. The photoaging process primarily resulted in the formation of EPFRs and reactive oxygen species (O2•−, ⋅OH, and 1O2), altering the physicochemical properties of TWP. The exposure of nematodes to 100 μg/L of TWP-50 (TWP with a photoaging time of 50 d) led to a significant decrease in locomotory behaviors (e.g., head thrashes, body bends, and wavelength) and neurotransmitter contents (e.g., dopamine, glutamate, and serotonin). Similarly, the expression of neurotransmission-related genes was reduced in nematodes exposed to TWP-50. Furthermore, the addition of free-radical inhibitors significantly suppressed TWP-induced neurotoxicity. Notably, correlation analysis revealed a significantly negative correlation between EPFRs levels and the locomotory behaviors and neurotransmitter contents of nematodes. Thus, it was concluded that EPFRs on photoaged TWP induce neurotoxicity by affecting neurotransmission. These findings elucidate the toxicity effects and mechanisms of EPFRs, emphasizing the importance of considering their contributions when evaluating the environmental risks associated with TWP.

Sediment is the ultimate sink of environmental pollutants. A total of 128 surface sediment samples were collected from 8 rivers and 3 reservoirs in Maoming City, Guangdong Province. This study assessed the content and distribution of brominated flame retardants in sediments. The acute toxicity effects of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDs) in sediments were evaluated using Caenorhabditis elegans as model organisms. The concentration of TBBPA in sediments ranged from not detected (ND) to 12.59 pg/kg and was mainly distributed in the central area, which was affected by the emission of TBBPA from residential and factory. The concentration of HBCDs ranged from ND to 6.31 pg/kg, and the diastereoisomer distribution was consistent, showing a trend close to the South China Sea. The composition pattem of HBCDs in the surface sediments from rivers were 41.73%62.33%, 7.89%-25.54%, and 18.76%-40.65% for a-, /3-, and y-HBCD, respectively, and in the sediments from reservoirs were 26.15%-45.52%, 7.44%-19.23%, and 47.04%-61.89% for a-, /3-, and y-HBCD, respectively. When the sum of concentrations of TBBPA and HBCD in sediments were above high levels, reactive oxygen species in nematodes significantly increased, resulting in an oxidative stress response. Intestinal permeability was also enhanced, causing intestinal damage. In addition, in terms of this study, TBBPA had a greater impact on biotoxicity compared to HBCDs, and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City, Guangdong Province. This study can complement the pollution database in the study area and provide basic data for pollution control. (c) 2024 The Research Center for Eco-Environmental Sciences, Chinese Academy of

Nanopolystyrene (NPS), a frequently employed nanoplastic, is an emerging environmental contaminant known to cause neurotoxicity in various organisms. However, the potential for transgenerational neurotoxic effects, especially from photoaged NPS (P-NPS), remains underexplored. This study investigated the aging of virgin NPS (V-NPS) under a xenon lamp to simulate natural sunlight exposure, which altered the physicochemical characteristics of the NPS. The parental generation (P0) of Caenorhabditis elegans was exposed to environmental concentrations (0.1-100 mu g/L) of V-NPS and P-NPS, with subsequent offspring (F1-F4 generations) cultured under NPS-free conditions. Exposure to 100 mu g/L P-NPS resulted in more pronounced deterioration in locomotion behavior in the P0 generation compared to V-NPS; this deterioration persisted into the F1-F2 generations but returned to normal in the F3-F4 generations. Additionally, maternal exposure to P-NPS damaged dopaminergic, glutamatergic, and serotonergic neurons in subsequent generations. Correspondingly, there was a significant decrease in the levels of dopamine, glutamate, and serotonin, associated with reduced expression of neurotransmission-related genes dat-1, eat-4, and tph-1 in the P0 and F1-F2 generations. Further analysis showed that the effects of P-NPS on locomotion behavior were absent in subsequent generations of eat-4(ad572), tph-1(mg280), and dat-1(ok157) mutants, highlighting the pivotal roles of these genes in mediating P-NPS-induced transgenerational neurotoxicity. These findings emphasize the crucial role of neurotransmission in the transgenerational effects of P-NPS on locomotion behavior, providing new insights into the environmental risks associated with exposure to photoaged nanoplastics.

In order to explore the pollution characteristics， ecological risks， and pollution sources of heavy metals in farmland soils around typical factories in Hunan Province， the content characteristics of eight heavy metals in farmland soils around fluoride factories， leather factories， and plating plants were analyzed. The geo-accumulation index and potential ecological risk index were used to evaluate the pollution and environmental risk of heavy metals. The correlation analysis， hierarchical cluster analysis， and principal component analysis were used to analyze the sources of heavy metals. The Monte-Carlo model was used to evaluate the probability risk of regional ecological risk. The results showed that the main pollution elements in the soil were Cd and Zn， and their mean values were 4.46 and 2.73 times the background values， respectively. Zn was at a mild pollution level in the soil of the three typical factories， and Cd was at a moderate pollution level in the whole fluoride factory. The pollution sources of heavy metals in the typical factories were mainly natural sources， industrial activity sources （industrial waste discharge， mineral mining， and smelting activities）， traffic sources， etc. The results of potential ecological risk assessment showed that the ecological risk of the fluoride factory was at a high risk level， and the ecological risk of the leather factory and plating plants was at a high risk level. Cd was the main contributing element. The results of Monte-Carlo probabilistic ecological risk assessment reduced the uncertainty of deterministic assessment， which could provide scientific basis for accurate risk management and control in the regions.

Brominated flame retardants (BFRs) exhibit excellent flame retardant properties and are widely used in various industries. Among the common BFRs, tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDs) pose substantial ecological and human health risks due to their extensive application and long-range transport. This study established 131 sample collection sites along the coast of the South China Sea (SCS) in Guangdong Province to assess the concentration, distribution, inventory, and ecological risk of TBBPA and HBCDs in surface sediments. The concentrations of TBBPA in SCS sediments ranged from < limit of detection (LOD) to 80 mu g/kg dry weight (dw), and those of HBCDs from < LOD to 18 mu g/kg dw. The diastereoisomers of HBCDs (alpha-, beta-, and gamma-HBCD) in the sediment samples accounted for 36 %, 13 %, and 51 %, respectively. Human activities, particularly those associated with nearby electronic waste disassembly and textile and garment industries, considerably influenced the dispersion of TBBPA and HBCDs. The inventories of TBBPA and HBCDs in Guangdong Province's SCS were estimated to be 3.2 x 10(5) kg and 7.2 x 10(4) kg, respectively. The average risk quotient values ranged from <0.01 to 0.016, indicating a low to negligible environmental risk. This study provides deeper insights into the distribution and scientific significance of HBCDs and TBBPA in SCS sediment samples, elucidates the current state of BFR contamination, and offers recommendations for future research on environmental safety and human health in the region.

Microplastics, recognized as emerging contaminants, are commonly observed to be charged in the environment, potentially exerting toxic effects on various organisms. However, the transgenerational reproductive toxicity and underlying mechanisms of polystyrene (PS), particularly carboxyl-modified PS (PS-COOH) and amino-modified PS (PS-NH2), remain largely unexplored. In this study, the parental generation (P0) of Caenorhabditis elegans was subjected to environmental concentrations (0.1-100 mu g/L) of PS, PS-COOH, and PS-NH2, with subsequent generations (F1-F4) cultured under normal conditions. Exposure to PS-NH2 at concentrations of 10-100 mu g/L exhibited more pronounced reproductive toxicity compared to PS or PS-COOH, resulting in decreased brood size, egg ejection rate, number of fertilized eggs, and cell corpses per gonad. Similarly, maternal exposure to 100 mu g/L of PS-NH2 induced more severe transgenerational reproductive effects in C. elegans. Significant increases in H3 on lysine 4 dimethylation (H3K4me2) and H3 on lysine 9 trimethylation (H3K9me3) levels were observed in the subsequent generation, concurrent with the transgenerational upregulation of set-30 and met-2 following parental exposure to PS, PS-COOH, and PS-NH2. Correlation analyses revealed significant associations between the expression of these genes with the reproductive ability. Molecular docking studies suggested that PS-NH2 exhibited higher affinity for SET-30 and MET-2. Further analysis demonstrated that transgenerational effects on reproduction were absent in set-30(gk315) and met-2(n4256) mutants, highlighting the pivotal role of set-30 and met-2 in mediating the transgenerational effect. This study provides novel insights into the environmental risks associated with negatively and positively charged microplastics.

Studies have shown that consuming aquatic products is the primary pathway for human uptake of polybrominated diphenyl ethers (PBDEs). This study collected seven types of aquatic products eaten in Guangzhou City. Gas chromatography-mass spectrometry (GC/MS) was used to investigate eight PBDE congeners to analyze their concentration, distribution, and potential risk. The concentration of PBDEs in aquatic products ranged from 1.92 to 91.11 ng/g lw, with BDE-209, BDE-99, and BDE-154 as the predominant PBDE congeners. Moreover, the concentrations and congener profiles of these contaminants vary in aquatic products. The highest accumulation level was found in shrimp and clams, primarily attributed to dietary habits, metabolic capacity, and accumulation of xenobiotics. According to the dietary questionnaire, the total consumption of aquatic animals was 82.64 g/day, with a significant non-carcinogenic risk to consumers in Guangzhou at higher levels of consumption (HI >= 1). Therefore, the maximum allowable daily consumption of grass carp, crucian carp, tilapia, Japanese seaperch, shrimp, clam and crab is 33.33, 55.00, 67.50, 44.44, 41.67, and 51.67 g/day, corresponding to daily intake frequencies of 5, 8, 10, 6, 6, 7, and 5 times/month, respectively. Our results could provide reasonable dietary advice for humans.

Neonicotinoid insecticides (NNIs) are extensively used in agricultural production in China due to their selective neurotoxicity towards target insects. In recent years, the rapid development of agriculture has increased the use and residue of NNIs. Consequently, the sediment environment, serving as the ultimate sink, is significantly impacted by NNIs. Upon release into the environment, NNIs can enter the human body through the food chain, posing potential ecological and human health risks. This study analyzed 79 sediment samples from two major river basins in North and South China, the Liaohe River basin in Liaoning Province and the Jianjiang River basin in Guangdong Province. The content, composition, distribution, and source of eight NNIs were analyzed, and assess the ecological and human health risks of the target compounds in these regions. The results indicated that the average concentration of NNIs in the sediments of the Jianjiang River basin (2.34 μg/kg) is slightly higher than that of the Liaohe River basin (2.32 μg/kg), and the sources of NNIs in the two areas were different, with differences in the sources of NNIs likely attributable to varying types of agricultural production. The risk assessment revealed that the ecotoxicological and public health risks were more pronounced in the Jianjiang River basin compared to the Liaohe River basin, underscoring the critical need for surveillance and management of hazardous substances like NNIs. The insights findings from this study can provide scientific guidance for the risk evaluation and environmental management of NNIs.

Microbeads used in personal care products have been one of the important sources of microplastics (MPs), and little has been reported on their environmental behaviors and health risks. The characteristics of environmentally persistent free radicals (EPFRs) and the toxicity assessment of MPs (environmentally relevant concentrations) from cosmetics during photoaging remains largely unknown. In this study, the formation of EPFRs on polyethylene (PE) microbeads from facial scrubs under light irradiation and their toxicity were investigated using C. elegans as a model organism. The results suggested that light irradiation induced the generation of EPFRs, which accelerates the aging process and alters the physicochemical properties of PE microbeads. Acute exposure to PE (1 mg/L) at photoaged times of 45–60 d significantly decreased the physiological indicators (e.g., head thrashes, body bends, and brood size). The oxidative stress response and stress-related gene expression were also enhanced in nematodes. The addition of N-acetyl-l-cysteine induced significant inhibition of toxicity and oxidative stress in nematodes exposed to 45–60 d of photoaged PE. The Pearson correlation results showed that the concentration of EPFRs was significantly correlated with physiological indicators, oxidative stress, and related-genes expression in nematodes. The data confirmed that the generation of EPFRs combined with heavy metals and organics contributed to toxicity induced by photoaged PE, and oxidative stress might be involved in regulating adverse effects in C. elegans. The study provides new insight into the potential risks of microbeads released into the environment during photoaging. The findings also highlight the necessity for considering the role of EPFRs formation in evaluating the impacts of microbeads.

水鸟通常栖息在湿地,属于食物链中的高级消费者,重金属很容易在水鸟体内积累.为了解鄂尔多斯国家级自然保护区水鸟体内的重金属累积、分布特征及其潜在来源,评估潜在毒性,对鄂尔多斯保护区水鸟体内不同组织(肌肉、肝脏和肾脏)中的重金属锌(Zn)、铜(Cu)、铅(Pb)、镉(Cd)和锰(Mn)含量进行分析.采用多元分析方法解析重金属潜在来源,使用毒性阈值评估重金属的潜在毒性.结果表明:(1)各重金属平均含量为Zn(79.73 mg·kg-1)(以干质量计,下同)＞Cu(35.80 mg·kg-1)＞Mn(5.64 mg·kg-1)＞Cd(2.5 mg·kg-1)＞Pb(0.75 mg·kg-1),其主要累积器官是肝脏和肾脏;水鸟中Zn、Cu和Mn含量存在显著的种间差异(P＜0.05);不同重金属在水鸟组织中的分布特征存在较大差异;(2)究其来源,水鸟体内的Zn、Cu和Mn可能与工业生产和农业活动的输入有关;Cd和Pb可能与农业活动(包括耕植施肥、畜牧养殖)的输入有关;(3)Cd是本研究中浓度超过毒性阈值的单一元素,对该保护区水鸟存在潜在毒性.因此,为降低该保护区中重金属带来的潜在健康危害,应加强对Cd的防控治理.

Microplastics are widely detected in the environment and induce toxic effects in various organisms. However, the properties and toxicity associated with environmentally persistent free radicals (EPFRs) in photoaged nanopolystyrene (NPS) remain largely unknown. We investigated the generation of EPFRs on photoaged NPS and their neurotoxicity and underlying mechanism in Caenorhabditis elegans. The results suggested that photoaging induces the generation of EPFRs and reactive oxygen species (O2•-, •OH, and 1O2), which altered the physicochemical properties (morphology, crystallinity, and functional groups) of NPS. Acute exposure to 1 μg/L of NPS-60 (NPS with light irradiation time of 60 d) significantly decreased locomotion behaviors and neurotransmitter contents (e.g., glutamate, serotonin, dopamine, and γ-aminobutyric acid). Treatment with N-acetyl-L-cysteine (NAC) by radical quenching test significantly reduced EPFRs levels on the aged NPS, and the toxicity of NAC-quenching NPS was decreased in nematodes compared to those in photoaged NPS. EPFRs also caused dysfunction of neurotransmission-related gene expression in C. elegans. Thus, EPFRs generated on photoaged NPS contributed to neurotoxicity by affecting dopamine, glutamate, serotonin, and γ-aminobutyric acid neurotransmission. The study highlights the potential risks of photoaged NPS and the contributions of EPFRs to toxicity.

In order to understand the spatial distribution and sources of heavy metals in surface sediments of MaoMing city and to reasonably evaluate the ecological risk of heavy metals in sediments of the study area, the contents of heavy metals (As, Hg, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) in surface sediments of eight rivers and three reservoirs were detected, and the risks of heavy metals were assessed using the geo-accumulation index (Igeo), potential ecological disk index (RI), and potential adverse biological impacts (ΣTUs). The sources of heavy metals were analyzed via correlation, principal component analysis (PCA), and positive matrix factorization (PMF). The results showed that the ω(Zn) (147.56 mg·kg-1) and ω(Hg) (0.20 mg·kg-1) were 3.72 and 2.25 times the background value, respectively, and the spatial distributions of Cd, Co, Cu, Mn, Ni, and Zn were in the order of northern>central>western>southeast. The geo-accumulation index results showed that Zn was at a moderate pollution level, 76.6% of the sampling sites of Hg were at a light-heavy pollution level, and other heavy metals were at a non-light pollution level. The results of potential ecological risk and potential adverse biological impacts indicated that the potential ecological risk index and toxicity effect of Gaozhou Reservoir were higher than those of other rivers, and Hg was the major contributor to heavy metal pollution. The three factors extracted from principal component analysis and positive matrix factorization represented natural sources, agricultural sources, and industrial sources, respectively. Therefore, in order to reduce the health hazards caused by heavy metals in sediments, a prevention and control system for the Hg element should be established.

Microplastics (MPs) are emerging environmental contaminants that often co-exist with tetrabromobisphenol A (TBBPA) in the environment. However, the joint effect of TBBPA and photoaged MPs at ambient concentrations remains unknown largely. In this study, the combined toxicity of ultraviolet-aged polystyrene (UV-PS) and TBBPA was investigated in Caenorhabditis elegans. UV irradiation could change the physical and chemical characteristics of polystyrene (PS), and UV-PS (90.218 μg/g) showed a stronger adsorption capacity than PS of 79.424 μg/g. Toxicity testing showed that 1 μg/L UV-PS enhanced the toxic effect of 1 μg/L TBBPA by reducing body length, locomotion behavior, and brood size in nematodes. Using ROS production, lipofuscin accumulation, and expression of gst-4::GFP as endpoints, the combined exposure of UV-PS and TBBPA induced stronger oxidative stress than TBBPA alone. Joint exposure to UV-PS and TBBPA significantly increased of Nile red and blue food dye in its intestinal tract compared to that in the TBBPA exposure group, indicating that co-exposure enhanced intestinal permeability. After co-exposure to UV-PS and TBBPA, the expression of the associated genes detected increased significantly. Therefore, UV-PS enhances the adverse effects of TBBPA through intestinal damage and oxidative stress in nematodes. These findings suggest that the co-presence of photoaged PS and TBBPA results in high environmental risks.

Pharmaceutical plants are an essential source of antibiotics emitted into the aqueous environment. The monitoring of target antibiotics in pharmaceutical plants through various regions is vital to optimize contaminant release. The occurrence, distribution, removal, and ecological risk of 30 kinds of selected antibiotics in 15 pharmaceutical plants in the Pearl River Delta (PRD) were investigated in this study. Lincomycin (LIN) showed the highest concentration (up to 56,258.3 ng/L) in the pharmaceutical plant influents from Zhongshan city. Norfloxacin (NFX) showed a higher detection frequency than other antibiotics. In addition, the spatial distribution of antibiotics in pharmaceutical plants showed significant differences, with higher concentrations of total antibiotics found in pharmaceutical plant influents in Shenzhen City than those of different regions in PRD. The treatment processes adopted by pharmaceutical plants were commonly ineffective in removing antibiotics, with only 26.7% of antibiotics being effectively removed (average removal greater than 70%), while 55.6% of antibiotics had removal rates of below 60%. The anaerobic/anoxic/oxic (AAO)-membrane bioreactor (MBR) combined process exhibited better treatment performance than the single treatment process. Sulfamethoxazole (SMX), ofloxacin (OFL), erythromycin-H2O (ETM-H2O), sulfadiazine (SDZ), sulfamethazine (SMZ), norfloxacin (NFX), and ciprofloxacin (CIP) in pharmaceutical plant effluents posed high or moderate ecological risk and deserve particular attention.