Rivers play a crucial role in collecting and transporting microplastics. Nonetheless, the degree to which microplastic pollution of freshwaters affects its biota remains understudied. Sampling of wild fishes has so far demonstrated that microplastic ingestion occurs commonly across species with alternate feeding modes, as well as in different environmental compartments. Due to the exploratory nature of many preceding studies, drawing insight about factors driving microplastic ingestion has remained difficult. It continues unknown for instance, what the importance of varying environmental microplastic concentrations is to predict ingestion rates in fish from those areas. Here we show that ingestion rates of microplastic particles (>300 μm) in the benthic round goby from the Rhine river were negligible (1 particle in 417 fish). Among the 535 visually selected putative microplastic fragments, stringent data processing steps to reduce the number of false positives during reference library searches, revealed the importance of taking such steps into account in comparison with other data processing routines. Our observations remained consistent, despite having collected fish from a strongly polluted site of the lower Rhine, which served as contrast to a significantly cleaner site upstream. These results demonstrate that higher environmental microplastic concentrations are not necessarily mirrored by higher ingestion rates in a given fish species.

Fructose was utilized as an additional co-substrate to systematically investigate the molecular mechanism of its boosting effect for the degradation of refractory dye reactive black 5 (RB5) by a natural bacterial flora DDMZ1. A decolorizing rate of 98% was measured for sample YE + FRU(200) (with 3 g/L fructose additionally to yeast extract medium, 10% (v/v) inoculation size of flora DDMZ1, 200 mg/L RB5) after 48 h. This result was 21% and 77%, respectively, higher than those of samples with only yeast extract or only fructose. Fructose was found to significantly stimulated both intracellular and extracellular azoreductase secretion causing enhanced activity. Metagenomic sequencing technology was used to analyze the functional potential of genes. A label-free quantitative proteomic approach further confirmed the encoding of functional proteins by the candidate genes. Subsequently, the molecular mechanism of RB5 degradation by candidate genes and functional proteins of the dominant species were proposed. This study provides important perspectives to the molecular mechanism of co-metabolic degradation of refractory pollutants by a natural bacterial flora.

Planting leafy vegetables, especially pakchoi, in cadmium (Cd) polluted farmland is easy to lead to excessive Cd content in edible parts, which results in high risk of food chain. In this study, a field experiment was carried out to study the effects of intercropping of pakchoi with Cd hyperaccumulator Sedum alfredii Hance, and the roles of endophytic bacterium SaMR12 was also investigated. When intercropping with Sedum, the growth of pakchoi was not affected but their Cd concentration and accumulation were significantly increased, while which were obviously decreased by SaMR12 inoculation. After intercropping, the biomass of Sedum was significantly reduced, but their Cd concentration increased. SaMR12 inoculation significantly increased Cd accumulation of Sedum, and which increased to 3 times in Sedum monoculture. Those results showed that although intercropping with hyperaccumulator could lead to higher risk of pakchoi in Cd polluted field, intercropping with SaMR12 inoculated Sedum can decrease Cd concentration of pakchoi and promote Cd absorption of Sedum, which indicated that this endophyte can be made into a microbial inoculum as a soil additive for the safe production of vegetables and the soil Cd pollution remediation.

The ongoing transition to renewable fuel sources has led to increased use of wood and other biomass fuels. The physiochemical characteristics of biomass combustion derived aerosols depends on appliances, fuel and operation procedures, and particles generated during incomplete combustion are linked to toxicity. Frequent indoor wood burning is related to severe health problems such as negative effects on airways and inflammation, as well as chronic hypoxia and pathological changes in placentas, adverse pregnancy outcome, preterm delivery and increased risk of preeclampsia. The presence of combustion-derived black carbon particles at both the maternal and fetal side of placentas suggests that particles can reach the fetus. Air pollution particles have also been shown to inhibit trophoblast migration and invasion, which are vital functions for the development of the placenta during the first trimester. In this study we exposed a placental first trimester trophoblast cell line to wood smoke particles emitted under Nominal Burn rate (NB) or High Burn rate (HB). The particles were visible inside exposed cells and localized to the mitochondria, causing ultrastructural changes in mitochondria and endoplasmic reticulum. Exposed cells showed decreased secretion of the pregnancy marker human chorionic gonadotropin, increased secretion of IL-6, disrupted membrane integrity, disrupted proliferation and contained specific polycyclic aromatic hydrocarbons (PAHs) from the particles. Taken together, these results suggest that wood smoke particles can enter trophoblasts and have detrimental effects early in pregnancy by disrupting critical trophoblast functions needed for normal placenta development and function. This could contribute to the underlying mechanisms leading to pregnancy complications such as miscarriage, premature birth, preeclampsia and/or fetal growth restriction. This study support the general recommendation that more efficient combustion technologies and burning practices should be adopted to reduce some of the toxicity generated during wood burning.

Research was conducted to study the response and detoxification mechanisms of earthworms collected from Cd-contaminated areas in Hunan Province, South China. Metaphire californica, the dominant earthworm species in fields, referred as earthworm-A and -B that collected from low- (0.81 mg kg⁻¹) and high-Cd soil (13.3 mg kg⁻¹), respectively, for exchanging incubation in laboratory. The results showed that earthworm-A gradually accumulated higher Cd when exposed in the high-Cd soil, whereas Cd concentration of earthworm-B decreased after being transferred to low-Cd soil (albeit BAFCd >20). The integrated biomarker response index was calculated with the biomarkers of antioxidant systems (e.g., superoxide dismutase (SOD), peroxidase (POD), glutathione (GSH), glutathione peroxidase (GPx), glutathione-S transferase (GST), and malondialdehyde (MDA)) and energy index (e.g., protein and glycogen) in M. californica. GSH, GPx, and GST contributed the most to the integrated biomarker response (IBR) in earthworm-A when exposed in high-Cd soil for 14 d. Earthworm-B responded with higher GST and GPx activities and decreased protein content in low-Cd soil. For 28 d, the response of earthworm-A was not evident in either low- or high-Cd soil, and the inductive effect of metal stress on earthworm-B tended to be stable, except for the higher MDA content (p < 0.05) when exposed in low-Cd soil. The IBR index of earthworm-B (2.93 and 3.40) in low- and high-Cd soil, respectively, was higher than that of earthworm-A (0.89 and 1.0). Overall, earthworm-A exhibited a detoxification process to resist high-Cd toxicity from low-to high-Cd soil. Earthworm-B exhibited a physiological resilience once its habitat had changed to a normal or low-Cd soil environment, possibly owing to the cost of its resistance adaptation to the historical highly contaminated soil in fields.

This work investigated levels of PAHs and HMs in fourteen species from seven genera of scleractinian corals, adjacent sediments, and surface seawater in Hainan, China. The sources of contaminations were analyzed as well. The results showed that scleractinian corals had a relatively higher bioaccumulation capacity for PAHs from sediments than for HMs. There were inter-species differences for these contaminants enriched in corals. Pavona varians and Porites lutea could accumulate PAHs more readily. While higher concentrations of Cr, Mn and Pb occurred in Favites flexuosa, other metal levels, such as for Ni, Cu, Zn and As, were found to be elevated in Pocillopora damicornis, as well as for Cd in Acropora echinata. It was found that PAHs originated from petrogenic and pyrolytic sources, and were mainly linked to onshore and on-sea activities, such as motorboats. Mn, Ni, As and Cd were from crustal materials or natural weathering, while Cr, Cu, Zn and Pb were non-crustal origin connecting with the use of anti-fouling boat paint and agricultural and/or aquacultural chemicals. This study suggested that corals could serve as good bioindicators for two types of chemical pollution in the reef system, especially for the two species P. varians and P. lutea for PAHs contaminants.

Carbon disulfide (CS₂) is seen an odor-toxic organic sulfur compound, which presents a major impact on global climate change. Therefore, the conversion of CS₂ into valuable chemicals is the key to reduce the concentration of CS₂ in the atmosphere. On the basis of a CS₂ fixation strategy, CS₂-storage materials (CS₂SMs) are firstly synthesized by the reaction of CS₂ with a binary ion-like liquid systems of ethylenediamine (EDA) and ethylene glycol derivatives (EGs) under mild condition. In view of the serious shortage of sulfur fertilizer and its important position in global agricultural production, it is a promising choice to use the CS₂SMs as a new type of green sulfur fertilizer to promote the growth of eggplant, tomato, sweet pepper and cucumber. In this work, the influence of CS₂SMs on the growth of plants were studied by taking plants irrigated by using various aqueous CS₂SMs solutions as experimental groups, and those irrigated by using water and NH₄HCO₃ as control groups. The experimental results showed that all CS₂SMs could promote plant height, stem diameter, root weight, flower bud number and leaf size. Especially, several CS₂SMs presented significant influence on fluorescence and fruit number. Further studies showed that the CS₂SMs as new energy resources sulfur-containing boosted leaf area, improved root development, enhanced photosynthesis and soil nutrient uptake, and promoted vegetative and reproductive growth of these four types of plants. Thus, this work provided a new strategy for the use of CS₂ as an indirect energy source for the experimental four plants.

Plastics have been widely reported to be present in the environment yet there are still many questions regarding the extent of this and the impacts these may have on both the environment and human health. The purpose of this investigation is to determine levels of micro and mesoplastic (MP), in the 1–5000 μm range, in commercially important species of finfish and shellfish. Additionally, to determine and compare the relative MP levels in edible versus non-edible tissues, and consider the wider implications in terms of human health concerns with a preliminary risk identification approach. For several fish species, samples taken from typically non-edible (gills, digestive system) and edible (muscle) flesh, and were analysed separately. Scallops, where all tissues are edible, were analysed whole. Significant differences were observed in the number of particles isolated from the finfish gills and digestive tissues relative to the control samples, but not in the edible flesh. For scallops, the abundance of particles in the Scottish samples did not vary significantly from the control, while the Patagonian scallops displayed significantly higher numbers of MPs. Characterisation of MPs by FTIR microscopy found that 16–60% (depending on species) were polyethylene terephthalate (PET) and polyethylene (PE) in origin. The risk identification results validate MPs as an emerging risk in the food chain and establish seafood as a vector for the exposure and uptake of MPs through the ingestion route for humans. Levels of MPs in seafood, and a direct link to the human food chain, suggests that their quantification be included as one food safety measure.

Microplastics (MPs, plastics < 5 mm) are a growing concern in ecosystems, being found in the soil and water environment. One of the primary sources of MPs has been suspected to be road dust in urban areas as it can flow into waters with runoff. To understand the occurrence of MPs (100 μm–5 mm) in surface road dust of three cities (Kusatsu, Shiga, Japan; Da Nang, Vietnam; and Kathmandu, Nepal), we collected surface road dust samples. The samples were pretreated (organic matter decomposition and gravity separation), and all MP candidates were individually observed by microscope for color, shape, and size; and analyzed their polymer types using fourier transform infrared spectrometry. The abundances of MPs 100 μm to 5 mm in size were 2.0 ± 1.6 pieces/m2 (13 polymer types) in Kusatsu, 19.7 ± 13.7 pieces/m2 in Da Nang (14 types), and 12.5 ± 10.1 pieces/m2 in Kathmandu (15 types). We classified the MPs into two groups; containers/packaging-MPs and rubber-MPs. Among all MPs, the containers/packaging-MPs accounted for 55 ± 5% of the polymer types composition. In contrast, the rubber-MPs accounted for 16 ± 6% of all MPs which were higher than those previously published for environmental water and sediment samples. The containers/packaging-MPs were fragments of various colors while most of the rubber-MPs were fragments or granules in black. The number–size distributions of MPs showed that the mode of formation explains the differences between their polymer types (tearing for containers/packaging-MPs and abrasion for rubber-MPs). In Da Nang and Kathmandu, the abundance of containers/packaging-MPs and rubber-MPs were correlated so that those MPs might be micronized from the originated materials in the sources with the similar composition (e.g. dump points). It was indicated that the characteristics of MPs pollution in surface road dust might be different depending on waste management practices.

Summertime ozone (O₃) concentrations over China continue to increase although the governmental Clear Air Actions have been carried out since 2013. The worst O₃ pollution is confronted over North China Plain. Ozone polluted days (with observed regionally-averaged maximum daily 8-h average (MDA8) O₃ concentrations exceeding 80 ppbv) in May–July in North China increased from 35 days in year 2014 to 56 days in year 2018, and persistent O₃ pollution episodes that lasted for 5 days or longer (OPEs5) contributed 14.3% and 66.1% to those O₃ polluted days in 2014 and 2018, respectively. Model simulations suggest that O₃ transport from central eastern China (including Shandong, Henan, Jiangsu and Anhui Provinces) contributes 36% of the enhanced O₃ concentrations in North China during OPEs5 relative to the seasonal mean. We find that emission control of volatile organic compounds in central eastern China is most effective to alleviate intensity of OPEs5 in North China.