The occurrence of emergent contaminants, 24 polybrominated diphenyl ethers (PBDEs), di(2-ethylhexyl)phthalate (DEHP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), diethyl phthalate (DEP), dimethyl phthalate (DMP), di-n-octyl phthalate (DnOP), bisphenol A (BPA) and nonylphenol (NP), was investigated in sediments and fishes collected from the Tamsui River system to determine the factors that influence their distribution and their risk to aquatic ecosystems and human health. The concentrations of total PBDEs, DEHP, DBP, BBP, DEP, DMP, DnOP, BPA and NP in sediments were 1–955, ND-23570, <50–411, <50–430, ND-80, ND-<50, ND-<50, 1–144, 3–19624 μg/kg dw, respectively. The spatial-temporal distribution trends of these compounds in sediments could be attributed to urbanization, industrial discharge and effluents from wastewater treatment plants. The PBDE congener distribution patterns (BDE-209 was the dominant congener) in sediments reflected the occurrence of debromination of BDE-209 and the elution of penta-BDE from the treated products. The concentrations of total PBDEs, DEHP, DBP, BBP, DEP, DMP, DnOP, BPA and NP in fish muscles were 2–66, 17–1046, <10–231, <10–66, <30, ND-<30, ND-<30, 0.4–7 and 3–440 μg/kg ww, respectively. The species-specific bioaccumulation of these compounds by fish was found and four species particularly showed high bioaccumulation potential. BDE-47 was the predominant BDE congener in fish muscles, suggesting high bioavailability and bioaccumulation of this compound. The results of biota–sediment accumulation factors showed that BDE-47, 99, 100, 153 and 154 had relatively high bioavailability and bioaccumulation potential for some fish species. The ecological risk assessment showed that the concentrations of BPA and NP in sediments were likely to have adverse effects on aquatic organisms (risk quotients > 1). The human health risk assessment according to hazard quotients (HQs) and carcinogenic risks (CRs) revealed no remarkable risk to human health through consumption of fish contaminated with BDE-47, 99, 100, 154, 209, DEHP, BPA and NP.

China has been seriously affected by particulate matter (PM) and gaseous pollutants in the atmosphere. In this study, we systematically analyse the spatio-temporal patterns of PM₂.₅, PM₁₀, SO₂, CO, NO₂, and O₃ and the associated health risks, using data collected from 1498 national air quality monitoring sites. An analysis of the averaged data from all the sites indicated that, from 2015 to 2018, annual mean concentrations of PM₂.₅, PM₁₀, SO₂ and CO declined by 3.2 μg m⁻³, 3.7 μg m⁻³, 3.9 μg m⁻³, and 0.1 mg m⁻³, respectively. In contrast, those of NO₂ and O₃ increased at rates of 0.4 and 3.1 μg m⁻³, respectively. Except for O₃, the annual mean concentrations of all pollutants were generally the highest in North China and lowest in the Tibetan Plateau. The concentrations were generally higher in the north of the country than in the south. In all regions of China, the pollutant concentrations were the highest in winter and lowest in summer, except for O₃, which showed an opposite seasonal pattern. Overall, the seasonal mean concentrations of all the pollutants (except for O₃) significantly decreased between the same seasons in 2018 and 2015, whereas the seasonal mean O₃ concentrations generally significantly increased, and/or remained at stable levels in all four seasons except for winter. Diurnal variations of all pollutants (except for O₃) exhibited a bimodal pattern with peaks between 8:00 and 11:00 a.m. and 9:00 and 12:00 p.m., whereas O₃ exhibited a unimodal pattern with maximum values between 5:00 and 7:00 p.m. No significant differences in the daily mean concentrations of all pollutants were found between weekdays and weekends in all regions, except for PM₂.₅ and PM₁₀ in Northeast China. In Northwest China and Southeast China, PM₂.₅ showed stronger correlations with NO₂ relative to SO₂, suggesting that NOₓ emission control may be more effective than SO₂ emission control for alleviating PM₂.₅ formation. Compared with 2015, the total PM₂.₅-attributable mortality, number of respiratory and cardiovascular diseases, and incidence of chronic bronchitis decreased overall by 23.4%–26.9% in 2018. In contrast, for O₃-attributable deaths, there was an increase of 18.9%. Our study not only improves the understanding of the spatial and temporal patterns of air pollutants in China, but also highlights that synchronous control of PM₂.₅ and O₃ pollution should be implemented to achieve dual benefits in protecting human health.

Comprehensively understanding the factors affecting physiology and fitness in urban wildlife requires concurrently considering multiple stressors. To this end, we simultaneously assessed how metal pollution and proximity to roads affect body condition and telomere shortening between days 8 and 15 of age in nestling great tits (Parus major), a common urban bird. We employed a repeated-measures sampling design to compare telomere shortening and body condition between nestlings from four urban study sites south of Antwerp, Belgium, which are located at different distances from a metal pollution point source. In addition, we explored associations between metal exposure and telomere dynamics on the individual level by measuring blood concentrations of five metals/metalloids, of which lead, copper and zinc were present at concentrations above the limit of detection. To assess whether roadway-associated stressors (e.g. noise and air pollution) might affect nestling condition and telomere shortening, we measured the proximity of nest boxes to roads. Metal exposure was not associated with nestling telomere length or body condition, despite elevated blood lead concentrations close to the metal pollution source (mean ± SE = 0.270 ± 0.095 μg/g wet weight at the most polluted study site), suggesting that nestlings may have some capacity to detoxify metals. However, nestlings from nest boxes near roads exhibited more telomere shortening between days 8 and 15 of age, and shorter telomeres at day 15. Nestlings in poorer condition also had shorter telomeres, but proximity to the road was unrelated to body condition. Thus, nutritional stress is unlikely to mediate the relationship between proximity to roads and telomere length. Rather, proximity to roads could have affected telomere shortening by exposing nestlings to air or noise pollution. Our study highlights that traffic-related pollution, which is implicated in human health problems, might also affect urban wildlife.

With the development of marine resources and marine transportation, oil spill accidents occur frequently which threaten the marine ecological environment and human life. In this paper, an oil spill model was established. The two-dimensional shallow water equation was discretized by the finite element weighted lumped mass method, and the time is discretized by the forward Euler scheme, then the planar two-dimensional hydrodynamic model was established. The model was verified by measure tidal level data. The oil particle drift model and oil spill weathering model were established in this paper, and it can be used to simulate the oil spill accidents on the sea area by inputting the terrain data, environmental conditions and oil spill information into the hydrodynamic model and oil spill model. The model is applied to Daya Bay, South China Sea, the oil spill behavior and destination under different residual currents were simulated and calculated, the pollution area of oil spill under clockwise residual flow is larger than that under anti-clockwise residual flow. The oil spill model is mainly used to simulate oil spill accidents on the sea surface such as ship oil spill accidents, and the simulation results can provide theoretical basis for taking effective emergency measures and risk assessment after oil spill.

Mercury isotope ratios in fish tissues have been used to infer sources and biogeochemical processes of mercury in aquatic ecosystems. More experimental studies are however needed to understand the internal dynamics of mercury isotopes and to further assess the feasibility of using fish mercury isotope ratios as a monitoring tool. We exposed Olive flounder (Paralichthys olivaceus) to food pellets spiked with varying concentrations (400, 1600 ng/g) of methylmercury (MeHg) and inorganic mercury (IHg) for 10 weeks. Total mercury (THg), MeHg concentrations, and mercury isotope ratios (δ²⁰²Hg, Δ¹⁹⁹Hg, Δ²⁰⁰Hg) were measured in the muscle, liver, kidney, and intestine of fish. Fish fed mercury unamended food pellets and MeHg amended food pellets showed absence of internal δ²⁰²Hg and Δ¹⁹⁹Hg fractionation in all tissue type. For fish fed IHg food pellets, the δ²⁰²Hg and Δ¹⁹⁹Hg values of intestine equilibrated to those of the IHg food pellets. Kidney, muscle, and liver exhibited varying degrees of isotopic mixing toward the IHg food pellets, consistent with the degree of IHg bioaccumulation. Liver showed additional positive δ²⁰²Hg shifts (∼0.63‰) from the binary mixing line between the unamended food pellets and IHg food pellets, which we attribute to redistribution or biliary excretion of liver IHg with a lower δ²⁰²Hg to other tissues. Significant δ²⁰²Hg fractionation in the liver and incomplete isotopic equilibration in the muscle indicate that these tissues may not be suitable for source monitoring at sites heavily polluted by IHg. Instead, fish intestine appears to be a more suitable proxy for identifying IHg sources. The results from our study are essential for determining the appropriate fish tissues for monitoring environmental sources of IHg and MeHg.

Nitrite (NO₂⁻)- and nitrate (NO₃⁻)-dependent anaerobic oxidation of methane (AOM) are two new additions in microbial methane cycle, which potentially act as important methane sinks in freshwater aquatic systems. Here, we investigated spatial variations of community composition, abundance and potential activity of NO₂⁻- and NO₃⁻-dependent anaerobic methanotrophs in the sediment of Jiulonghu Reservoir (Zhejiang Province, China), a freshwater reservoir having a gradient of increasing nitrogen loading from upstream to downstream regions. High-throughput sequencing of total bacterial and archaeal 16S rRNA genes showed the cooccurrence of Candidatus Methylomirabilis oxyfera (M. oxyfera)-like and Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like anaerobic methanotrophs in the examined reservoir sediments. The community structures of these methanotrophs differed substantially between the sediments of upstream and downstream regions. Quantitative PCR suggested higher M. oxyfera-like bacterial abundance in the downstream (8.6 × 10⁷ to 2.8 × 10⁸ copies g⁻¹ dry sediment) than upstream sediments (2.4 × 10⁷ to 3.5 × 10⁷ copies g⁻¹ dry sediment), but there was no obvious difference in M. nitroreducens-like archaeal abundance between these sediments (3.7 × 10⁵ to 4.8 × 10⁵ copies g⁻¹ dry sediment). The ¹³CH₄ tracer experiments suggested the occurrence of NO₂⁻- and NO₃⁻-dependent AOM activities, and their rates were 4.7–14.1 and 0.8–2.6 nmol CO₂ g⁻¹ (dry sediment) d⁻¹, respectively. Further, the rates of NO₂⁻-dependent AOM in downstream sediment were significantly higher than those in upstream sediment. The NO₃⁻ concentration was the key factor affecting the spatial variations of abundance and activity of NO₂⁻-dependent anaerobic methanotrophs. Overall, our results showed different responses of NO₂⁻- and NO₃⁻-dependent anaerobic methanotrophs to increasing nitrogen loading in a freshwater reservoir.

Microplastics represent a growing environmental concern in the aquatic environment due to its size resemblance to microplankton in addition to its ability to act as concentrators of persistent organic pollutants (POPs). Among them, polybrominated diphenyl ethers (PBDEs) stand out as POPs with dangerous levels in the aquatic environment. In this paper we have developed a methodology for studying the sorption and extraction process of twelve congeners of PBDE from four microplastics: polyethylene terephthalate (PET), polypropylene (PP), low density polyethylene (LDPE) and polystyrene (PS). We have proved that there is a dependence between the polymer composition and the solvent used for the extraction of the analytes. The extraction is function of the ability of the solvent to partially or totally dissolve the plastic that will allow the analyte to have a greater capacity to be released from the polymer structure. The solution of the polymer is achieved by making the free energy (ΔG, or Gibbs potential) of the system negative making the process occurs spontaneously, this will depend on the solubility parameter (∂), specific of both, solvent and polymer. Therefore, this study helps to determine which methodology to be applied for the extraction of pollutants before the start of the analysis. This approach has been applied to microplastic samples collected in different locations in the four oceans and collected from the Barcelona World Race (BWR) 2014–2015 sailing race.

While extreme high temperatures are an important aspect of global warming, their effects on organisms are relatively understudied, especially in ecotoxicology. Sequential exposure to heat spikes and pesticides is a realistic scenario as both are typically transient stressors and are expected to further increase in frequency under global warming. We tested the effects of exposure to a lethal heat spike and subsequently to an ecologically relevant lethal pulse exposure of the pesticide chlorpyrifos in the larvae of mosquito Culex pipiens. The heat spike caused direct and delayed mortality, and resulted in a higher heat tolerance and activity of acetylcholinesterase, and a lower fat content in the survivors. The chlorpyrifos exposure caused mortality, accelerated growth rate, and decreased the heat tolerance and the activity of acetylcholinesterase. The preceding heat spike did not change how chlorpyrifos reduced the heat tolerance. Notably, the preceding heat spike did lower the lethal effect of the pesticide, which makes an important novel finding at the interface of ecotoxicology and global change biology, and adds a new dimension to the “climate-induced toxicant sensitivity” (CITS) concept. This may be due to both survival selection and cross-tolerance, and therefore likely a widespread phenomenon. Our results emphasize the importance of including extreme high temperatures as an important transient global change stressor in ecotoxicology.

Microplastic (MP) pollution and its potential to concentrate and transport organic contaminants in environments have recently gained widespread attention. Compared to traditional nonpolar plastics such as polypropylene (PP) and polyethylene (PE), study about the environmental behavior of polyurethane (PT), polyuria (PU) and urea-formaldehyde resin (UF), which are typically used as shell materials for pesticide microcapsules and have polar structure is scarce. In the present study, we investigated the sorption capacities and binding mechanisms of PT, PU and UF for three polycyclic aromatic hydrocarbons (PAHs, naphthalene, phenanthrene (PHE), and pyrene) and two PHE derivates (ethylphenanthrene-2-carboxylate (2-CPHE) and 2-methylphenathrene (2-MPHE)) selected as the model compounds, and the effects of salinity and UV and/or H₂O₂ aging treatments on PHE sorption to MPs. The results showed that PT, PU and UF had negative surface charges, micron-scaled sizes and abundant polar functional groups containing O and N elements. PT, PU and UF could sorb PAHs efficiently with sorption coefficients (Kd) being in the range of 8.11 × 10³–9.53 × 10⁵ (L/Kg) and partitioning was the main sorption mechanism with polar interactions (H-boning and p/π-π EDA interactions) also contributing. The sorption capacity of the three MPs changed mainly depending on their glass transition temperatures (Tg). Furthermore, high salinity decreased the surface zeta-potential of the MPs and enhanced PHE sorption to MPs. In addition, aging treatments with UV and/or H₂O₂ markedly decreased the Tg of PT and enhanced its sorption capacity for PHE, while opposite results were obtained for PU. The findings on the sorption mechanisms of PAHs to agricultural MPs are useful for predicting the transport, fate and persistence of the co-existing HOCs in agricultural ecosystems and provide a scientific basis for the comprehensive risk assessment of agricultural MPs.

Pesticides pollution has caused serious environmental problems in recent years, and mounting evidence has shown that more and more insecticides have serious risk in human health. Emamectin Benzoate formally regarded as a highly safety insecticide based on its exclusive targets, but the cytotoxicity to human lung was ignored for a long time. In the present study, bioassay experiments were used to assess the toxicity of the Emamectin Benzoatein on human non-target cells including cell viability assay, DNA damage assay, flow cytometer assay and western blotting assay. The results indicated that Emamectin Benzoatecan cause the inhibition of the proliferation, cytochrome c release, activation of caspase-3/9 and increase Bax/Bcl-2 ratio, which means it induced the cytotoxicity on 16HBE cells associated with the mitochondrial apoptosis. Besides, the DNA damge caused by the Emamectin Benzoate suggest it has a potential genotoxic effect on human lung cells.