Natural organic matter (NOM) affects the environmental behaviors of AgNPs, which may change their phytotoxicity to plants. However, more evidence can be provided to illustrate how NOM influences AgNPs-induced phytotoxicity. In this study, using rice (Oryza sativa) as a model, the effects of NOM, Suwannee River humic acid (SRHA) and fulvic acid (FA), on the dissolution and phytotoxicity of AgNPs were investigated. Silver ions decreased in both AgNPs and AgNO₃ solution in the presence of NOM, and the effect of SRHA was stronger than FA. Image-XRF (iXRF) results showed that Ag mainly remained in the root rather than the shoot of rice seedling exposed to AgNPs. NOM mitigated the negative effects of AgNPs and AgNO₃ on rice with lower germination inhibition rate, less chlorophyll reduction, more relative biomass and less O₂•⁻ content. Moreover, NOM improved root cell viability according to FDA fluorescent dye as well as maintained the normal root morphology. Interestingly, the neutral sugars content from pectin, hemicellulose 1, hemicellulose 2 and cellulose of root cell wall in AgNPs and AgNO₃ treatments differed from the control, while it was close to the regular content in AgNPs/AgNO₃+SRHA/FA groups, which implied that NOM regulated the changes. Besides, SRHA led to less germination and less relative biomass than FA due to different chemical characters. Thus, NOM needs to be considered when studying the phytotoxicity of AgNPs.

Ingestion of microplastics by marine organisms has been well documented, but their interaction with chemical pollutants has not been sufficiently addressed. The aim of this study was to determine the individual and combined effects of chlorpyrifos (CPF) and polyethylene microplastics (MP) on the survival, fecundity, feeding and egg viability of Acartia tonsa, a calanoid copepod widely distributed in planktonic communities. The median lethal concentration obtained for CPF was higher (LC₅₀ = 1.34 μg/L) than for the combination with MP (LC₅₀ = 0.37 μg/L), or CPF-loaded MP (LC₅₀ = 0.26 μg/L). Significant effects were also observed for feeding and egg production (EC₅₀ = 0.77 and 1.07 μg/L for CPF, 0.03 and 0.05 μg/L for CPF combined with MP, 0.18 and 0.20 μg/L for CPF-loaded MP). No significant effects were observed in the exposure to ‘virgin’ MP. This study confirms the role of MP as vectors of pollutants to marine organisms and supports the increased availability of certain toxicants carried out by MP. The effects observed in fitness-related responses suggest potential damage to A. tonsa populations. The comparison of the results obtained here with environmental concentrations indicates that the combined exposure to CPF and MP could constitute a risk to A. tonsa in the natural environment.

Biochar sequesters cadmium (Cd) by immobilisation, but the process is often less effective in field trials than in the laboratory. Therefore, the involvement of soil components should be considered for predicting field conditions that could potentially improve this process. Here, we used biochar derived from Spartina alterniflora as the amendment for Cd-contaminated soil. In simulation trials, a mixture of kaolin, a representative soil model component, and S. alterniflora-derived biochar immobilised Cd by forming silicon-aluminium-Cd-containing complexes. Interestingly, the biochar recalcitrance index value increased from 48% to 53%–56% because of the formation of physical barriers consisting of kaolinite minerals and Cd complexes. Pot trials were performed using Brassica chinensis for evaluating the effect of S. alterniflora-derived biochar on plant growth in Cd-contaminated soil. The bio-concentration factor values in B. chinensis were 24%–31% after soil remediation with biochar than in control plants. In summary, these results indicated that soil minerals facilitated Cd sequestration by biochar, which reduced Cd bioavailability and improved the recalcitrance of this soil amendment. Thus, mechanisms for effective Cd remediation should include biochar-soil interactions.

The increasing prevalence and spread of antibiotic resistance genes (ARGs) in intensive aquaculture environments are of great concern to food safety and public health. However, the level of ARGs and their potential propagation factors in an industrial recirculating aquaculture system (RAS) have not previously been comprehensive explored. In this study, the levels of 14 different ARG markers and 2 kinds of mobile genetic elements (MGEs) were investigated in a RAS (including water, fish, feces, pellet feed meal, and biofilm samples) located northern China. qnrA, qnrB, qnrS, qepA, aac(6′)-Ib, and floR were dominant ARGs, which average concentration levels were presented at 4.51–7.74 copies/L and 5.36–13.07 copies/g, respectively, suggesting that ARGs were prevalent in RAS with no recorded history of antibiotic use. Elevated level of ARGs was found in water of RAS even after the final UV treatment compared with its influent. In RAS, Proteobacteria, Verrucomicrobia, Bacteroidetes, and Planctomycetes were the predominant phyla. Notably, elevated levels of potential opportunistic pathogens were observed along with abundant ARGs suggesting an increasing risk of capturing ARGs and MGEs for human pathogens. This study has revealed for the first time that reared fish, their feces, pellet feed meal as the introduction sources and the selection roles of treatment units co-driven the ARG profile, and the co-selection of water environmental factors and their consequently induced bacterial community shifts formed by their influence are the determining drivers for the ARG propagation in RAS.

Short-term exposure to air pollution has pro-thrombotic effects and triggers thrombo-embolic events such as myocardial infarction or stroke in adults. This study evaluates the association between short-term variation in air pollution and treatments for acute thrombo-embolic events among the whole Belgian population. In a bidirectional time-stratified case-crossover design, we included 227,861 events treated with endovascular intervention and 74,942 with antithrombotic enzymes that were reimbursed by the Belgian Social Security between January 1st, 2009 and December 31st, 2013. We compared the concentrations of particulate matter (PM) air pollution (PM₁₀ and PM₂.₅), as estimated at the municipality level on the day of the event (lag 0) and two days earlier (lag 1 and lag 2) with those of control days from the same month, matched by temperature and accounting for day of the week (weekend vs week days). We applied conditional logistic regression models to obtain odds ratios (OR) and their 95% CI for an increase of 10 μg/m³ (PM₁₀) or 5 μg/m³ (PM₂.₅) in pollutant concentrations over three lag days (lag 0, 1 and 2). We observed significant associations of PM₁₀ and PM₂.₅ with treatment of acute thrombo-embolic events at the three lags. The strongest associations were observed for air pollution concentrations on the day of the event (lag0). Increases of 10 μg/m³ PM₁₀ and 5 μg/m³ PM₂.₅ on lag0 increased the odds of events treated with endovascular intervention by 2.7% (95%CI:2.3%–3.2%) and 1.3% (95%CI:1%–1.5%), respectively, and they increased the odds of events treated with antithrombotic enzymes by 1.9% (95%CI:1.1–2.7%) and 1.2% (95%CI:0.7%–1.6%), respectively. The associations were generally stronger during autumn months and among children. Our nationwide study confirms that acute exposure to outdoor air pollutants such as PM₁₀ or PM₂.₅ increase the use of medication and interventions to treat thrombo-embolic events.

Southwestern China contains the largest and most well-developed karst region in the world, and the potentially toxic elements (PTEs) content in the soils of the region is remarkably high. To explore the internal and external control factors and sources of soil PTEs enrichment in this area and to provide a basis for the treatment of PTE pollution, 113 soil samples were collected from Hengxian County, a karst region in Guangxi Province, southwestern China. The importance of eighteen influencing factors including parent material, weathering, physicochemical properties, topography and human activities were quantitatively analyzed by (partial) redundancy analysis. The sources of PTEs were identified using the Pb isotope ratio and absolute principal component score/multiple linear regression (APCS-MLR) model. The contents of all soil PTEs were higher than the corresponding background values of Guangxi soils. The contents in Cu, Zn, Cd, Hg and Pb were the highest in the soil from carbonate rock. The factor group of geological background and weathering explained 26.5% for the accumulation and distribution of soil PTEs and the influence of physicochemical properties was less than 2% but increased to 25.6% through interaction with weathering. Fe (47.1%), Al (42.1%), Mn (22%), chemical index of alteration (12.8%) and clay (11.9%) were the key factors affecting the soil PTEs, while the influence of human activities was weak. Pb isotope ratio and APCS-MLR classified 62.8–74% of soil PTEs as derived from natural sources, whereas 18.23% and 18.95% were derived from industrial activities and agricultural practice/traffic emissions, respectively. The Pb isotope ratio showed that the natural sources account for up to 90% of the Pb in the soil from carbonate rock, the highest contribution among the studied soils. The results of the study can provide background information on the soil PTEs contamination in the karst areas of China and other areas worldwide.

Mosses are frequently used to monitor atmospheric metal contamination but few studies on metal adsorption under controlled conditions are available. Here, the accumulation of the heavy metals copper and zinc was studied in the acrocarp moss Atrichum undulatum. An in vitro culture of A. undulatum was established and the same line, size and equally old remets were exposed to six different treatments representing various metal exposure times and washing scenarios as rain simulation. The metal treatments were done in copper and zinc salts (Cu-acetate, CuSO4, ZnSO4 and ZnCl2, respectively). Energy-Dispersive X-ray microanalysis (EDX) was employed to detect bound heavy metals on the moss plantlets. Element distribution in stems and leaves was measured separately. The aqueous solution of metal salts facilitated an adsorption of both elements in the moss tissue as compared to solid medium. Furthermore, A. undulatum can tolerate pollution of zinc and copper in a distinctive extent; our data point towards a higher zinc tolerance whereas copper is rather harmful. However, semi-quantitatively, less zinc was detected within the moss tissue compared to copper. Interestingly, a strong positive correlation between the accumulation of copper/zinc and iron, and a strong negative correlation between copper/zinc and magnesium, respectively, was documented.

The effects of the continuous accumulation of Zinc (Zn) on the fate of antibiotic resistance genes (ARGs) in constructed wetland-microbial fuel cells (CW-MFCs) remain unclear. In this study, the impacts of Zn addition and a circuit mode on antibiotic removal, occurrence of ARGs, the bacterial community, and bacterial functions were investigated in three groups of CW-MFCs. The results showed that continuous Zn exposure enriched the target ARGs during the initial stage, while excessive Zn accumulation decreased antibiotic removal and the abundance of ARGs. A principal component analysis demonstrated that ARGs and the bacterial community distribution characteristics were significantly impacted by the mass accumulation of antibiotics and Zn, as well as the circuit mode. A redundancy analysis, partial least squares path modeling, and Procrustes analysis revealed that the accumulation of antibiotics and Zn, the composition of the bacterial community, the circuit mode, and the abundance of intI associated with horizontal gene transfer jointly contributed to the distributions of ARGs in the electrodes and effluent. Moreover, continuous exposure to Zn decreased the bacterial diversity and changed the composition and function of the bacterial community predicted using PICRUSt tool. The co-occurrence of ARGs, their potential hosts and bacterial functions were further revealed using a network analysis. A variation partition analysis also showed that the accumulation of target pollutants and the circuit mode had a significant impact on the bacterial community composition and functions. Therefore, the interaction among ARGs, the bacterial community, bacterial functions, and pollutant accumulations in the CW-MFC was complex. This study provides useful implications for the application of CW-MFCs for the treatment of wastewater contaminated with antibiotics and heavy metals.

Urbanization and industrialization have elevated metal concentrations in soils. However, systematic investigation on their availability in regional soils under industrial impacts is lacking. In this study, 230 paired soil-rice samples were collected from two areas in Southeast China, with low and high industrial impacts. Classic equilibrium-based CaCl₂ and EDTA extraction methods, and dynamic-based diffusive gradients in thin-films (DGT) technique were used to study metal availability in soils, with the results being compared with metal concentrations in soils and rice grains. Generally, Cd, Ni, Cu, Zn, Cr and Pb concentrations in soils exceeded the Chinese Soil Quality Standard (GB15618-2018), whereas only Cd and Ni in some rice grains exceeded the Chinese Safety Guidelines. CaCl₂ and EDTA extractions, DGT method and soil total metal concentrations provided good predication of grain Cd (R = 0.51–0.66, p < 0.01), whereas only CaCl₂ and DGT tests provided good predication of grain Ni (R = 0.36–0.47, p < 0.01). Overall, CaCl₂ extraction best predicted Cd and Ni accumulation in rice grains, explaining 66% of grain Cd and 47% of grain Ni. The extraction rate of available Cd was higher than that of Ni, indicating higher Cd availability than Ni, consistent with the parameters (response time, Tc, and desorption rate, k–₁) from DIFS (DGT-induced flux in soils) model and bioconcentration factor values. This study showed that, at regional scale, CaCl₂ extraction method is efficient in predicting Cd and Ni accumulation in rice grains from contaminated soils.

Epidemiology suggests ambient temperature is the triggers and potential activator of asthma. The role of high and low temperatures on airway inflammation of asthma, and the underlying molecular mechanism are not yet understood. A mouse model of asthma was adopted in our experiment. The BALB/c mice were exposed at different temperature for 4 h (2 h in the morning and 2 h in the afternoon) on weekday. The exposure temperatures were 10 °C, 24 °C and 40 °C. Ovalbumin (OVA) was used to sensitize the mice on days 14, 18, 22, 26, and 30, followed by an aerosol challenge for 30 min from day 32–38. After the final OVA challenge, lung function, serum protein and pulmonary inflammation were assessed. Comparing the OVA with the saline group at 24 °C, we saw a significant increase in: serum Total-IgE (p < 0.05); OVA-sIgE (p < 0.01); IL-4 (p < 0.05); IL-1β (p < 0.01); IL-6 (p < 0.01); TNF-α (p < 0.01); and the ratio of IL-4/IFN-γ (p < 0.01). At the same time, there was a significant decrease in IFN-γ (p < 0.01). As the temperature increase, there is a U shape for immune proteins and pro-inflammatory factors with a peak value at 24 °C, exception for IFN-γ (inverted U-shape). After the high and low temperature exposure, the Ri and Re increased significantly, while Cldyn decreased significantly compared with the 24 °C group. Histopathological analysis of the OVA groups showed airway remodeling, airway wall thickening and deforming, and subepithelial fibrosis. More obvious changes were found in the high and low temperature exposure groups. The immunohistochemistry suggested that TRPs changed with temperatures. High and low temperatures can aggravate airway inflammation in a mouse model of asthma. TRPs play an important role in temperature aggravation of allergic asthma. The results suggest that asthmatics should avoid exposure to high and low temperatures for too long time.