The increase of gaseous ammonia (NH₃) concentration in the atmosphere significantly impacts the regional air quality, human health, and the nitrogen cycle of ecosystems. This study aims to verify the reanalyzed product of IASI NH₃ (the ANNI-NH₃-v2.1R-I, hereafter referred to as IASI_NH₃_R) and to analyze the spatial and temporal characteristics of atmospheric NH₃ during 2008–2016 and its underlying influencing factors. Our results show a good agreement between spatial pattern and temporal (annual and monthly) trend of the satellite-derived surface NH₃ concentrations and the measured near-ground NH₃ measurements over different land covers in Eastern China, suggesting the IASI_NH₃_R product can be used to investigate spatial and temporal trends of atmospheric NH₃ concentration. The annual mean NH₃ column concentrations peaked in the North China Plain (averaged 12 × 10¹⁵ mol cm⁻² yr⁻¹) and showed a significant increasing trend at a rate of 0.6 × 10¹⁵ mol cm⁻² yr⁻¹ during the entire period, which can be ascribed to densely populated, intensive agricultural activities and substantial reduction of SO₂ and NO₂ emissions since 2011. The NH₃ column concentrations show a slight increase in winter in most regions of China, probably due to less precipitation amount and increased uncertainty for lower NH₃ columns and the thermal contrast (TC). A large seasonal variation of NH₃ column concentrations was observed, with the highest values in summer and the lowest in autumn. Such seasonal variation is mainly affected by seasonal differences in NH₃ emissions and meteorological conditions. Our results suggest that the current control measures effectively decreased SO₂ and NO₂ pollution but are not yet apparent in the mitigation of atmospheric NH₃ pollution, which also merits more attention considering that no effective measures are being implemented for NH₃ emission control at a regional or national scale in China.

Hydroponic experiments were conducted to study the effects of microplastic particles of polystyrene (PS) and polytetrafluoroethylene (PTFE) on arsenic (As) content in leaves and roots of rice seedlings, and the changes in root vigor and physiological and biochemical indicators under single or combined PS and PTFE with As(III) treatment. Rice biomass decreased with increasing concentrations of PS, PTFE, and As(III) in the growth medium. The highest root (leaf) biomass decreases were 21.4% (10.2%), 25.4% (11.8%), and 26.2% (16.2%) with the addition of 0.2 g L⁻¹ PS, 0.2 g L⁻¹ PTFE, and 4 mg L⁻¹ As(III), respectively. Microplastic particles and As(III) inhibited biomass accumulation by inhibiting root activity and RuBisCO activity, respectively. The addition of As(III) and microplastic particles (PS or PTFE) inhibited photosynthesis through non-stomatal and stomatal factors, respectively; furthermore, net photosynthetic rate, chlorophyll fluorescence, and the Chl a content of rice were reduced with the addition of As(III) and microplastic particles (PS or PTFE). Microplastic particles and As(III) induced an oxidative burst in rice tissues through mechanical damage and destruction of the tertiary structure of antioxidant enzymes, respectively, thereby increasing O₂⁻ and H₂O₂ in roots and leaves, inducing lipid peroxidation, and destroying cell membranes. When PS and PTFE were added at 0.04 and 0.1 g L⁻¹, respectively, the negative effects of As(III) on rice were reduced. Treatment with 0.2 g L⁻¹ PS or PTFE, combined with As(III), had a higher impact on rice than the application of As(III) alone. PS and PTFE reduced As(III) uptake, and absorbed As decreased with the increasing concentration of microparticles. The underlying mechanisms for these effects may involve direct adsorption of As, competition between As and microplastic particles for adsorption sites on the root surface, and inhibition of root activity by microplastic particles.

Chromium (Cr) is an internationally recognized carcinogenic hazard that causes serious pulmonary toxicity. However, Cr-induced pulmonary toxicity lacks effective treatment to date. Sulforaphane (SFN), a well-known organosulfur compound, has gained increasing attention because of its unique biological function. This study investigates if SFN could decrease K₂Cr₂O₇-induced pulmonary toxicity and a potential mechanism involved using a rat 35-day Cr-induced pulmonary toxicity model and the mouse alveolar type II epithelial cell line (MLE-12). The results showed that SFN prevented Cr-induced oxidative stress, histopathological lesions, inflammation, apoptosis, and changes in protein kinase B (Akt) and glycogen synthase kinase 3 beta (GSK-3β) levels in vivo and in vitro. However, SFN can not play the protective effect against K₂Cr₂O₇-induced cell injury after treating by an Akt-specific inhibitor (MK-2206 2HCl) in MLE-12 cells. Furthermore, SFN increased the expression of nuclear factor-E2-related factor-2 (Nrf2) phase II detoxification enzymes. Collectively, this study demonstrates that SFN prevents K₂Cr₂O₇-induced lung toxicity in rats through enhancing Nrf2-mediated exogenous antioxidant defenses via activation of the Akt/GSK-3β/Fyn signaling pathway. SFN may be a novel natural substance to cure Cr-induced lung toxicity.

Microplastics are plastic fragments of particle sizes less than 5 mm, which are widely distributed in marine and terrestrial environments. In this study, earthworms Eisenia fetida were exposed to 100 and 1000 μg of 100 nm and 1300 nm fluorescent polystyrene microplastics (PS-MPs) per kg of artificial soil for 14 days. Uptake or accumulation of PS-MPs in earthworm intestines, histopathological changes, oxidative stress, and DNA damage were assessed to determine the toxicological effects of PS-MPs on E. fetida. The results showed that the average accumulated concentrations in the earthworm intestines were higher for 1300 nm PS-MPs (0.084 ± 0.005 and 0.094 ± 0.003 μg/mg for 100 and 1000 μg/kg, respectively) than for 100 nm PS-MPs (0.015 ± 0.001 and 0.033 ± 0.002 μg/mg for 100 and 1000 μg/kg, respectively). In addition, histopathological analysis indicated that the intestinal cells were damaged after exposure to PS-MPs. Furthermore, PS-MPs significantly changed glutathione (GSH) level and superoxide dismutase (SOD) activity. The GSH levels were 86.991 ± 7.723, 165.436 ± 4.256–167.767 ± 18.642, and 93.590 ± 4.279–173.980 ± 15.523 μmol/L in the control, 100 nm, and 1300 nm PS-MPs treatment groups. In addition, the SOD activities were 10.566 ± 0.621, 9.039 ± 0.787–9.408 ± 0.493, and 7.959 ± 0.422–9.195 ± 0.327 U/mg protein for the control, 100 nm, and 1300 nm PS-MPs treatment groups, respectively, indicating that oxidative stress was induced after PS-MPs exposure. Furthermore, the comet assay suggested that exposure to PS-MPs induced DNA damage in earthworms. Overall, 1300 nm PS-MPs showed more toxic effect than 100 nm PS-MPs on earthworms. These findings provide new insights regarding the toxicological effects of low concentrations of microplastics on earthworms, and on the ecological risks of microplastics to soil animals.

(±) - PEN is a chiral fungicide widely used to control powdery mildew in agriculture. Currently, only a few studies have investigated the toxic effects of (±) – penconazole ((±) – PEN) on non-target organisms, and whether (±) - PEN from the enantiomeric level have toxic effects remains unclear. In this study, we systematically evaluated the effects of exposure to (±) – PEN, (+) – PEN and (−) – PEN on liver function in mice. Biochemical and histopathological analyses showed that exposure to (±) – PEN and (−) – PEN led to significant liver damage and inflammation. However, exposure to (+) – PEN treatment did not cause no adverse effects on liver function and inflammation. ¹H-NMR-based metabolomics revealed that exposure to (±) – PEN, (+) – PEN and (−) – PEN led to the animals developing liver metabolic disorder that was caused by changes in glycolipid metabolism. Quantitative analysis of genes regulating glycolipid metabolism revealed that expression of gluconeogenesis and glycolytic pathway genes were altered in individuals exposed to (±) – PEN, (+) – PEN and (−) – PEN. We also found that (±) – PEN, (+) – PEN and (−) – PEN have different effects on lipid metabolism of the liver. Exposure to (±) – PEN and (−) – PEN resulted in significant accumulation of lipids by regulating fatty acid synthesis, triglyceride synthesis, and fatty acid β oxidation pathways. In summary, we found different toxicological effects in individuals exposed to (±) – PEN, (+) – PEN and (−) – PEN. The results of this study are important for assessing the potential health risks of (±) – PEN.

Fluorotelomer alcohols (FTOHs) are important precursors of perfluorocarboxylic acids (PFCAs) in the environment and biota. With the growing application of 6:2 FTOH [F(CF₂)₆CH₂CH₂OH] in product formulation, it is becoming increasingly urgent to investigate its biological fates in different species. In this study, biotransformation of 6:2 FTOH by young soybean plants (Glycine max L. Merrill) were investigated using hydroponic experiments. During the 144 h-exposure, 6:2 FTCA [F(CF₂)₆CH₂COOH], 6:2 FTUCA [F(CF₂)₅CFCHCOOH], 5:3 FTUCA [F(CF₂)₅CHCHCOOH], 5:3 FTCA [F(CF₂)₅CH₂CH₂COOH], PFHxA [F(CF₂)₅COOH] and PFPeA [F(CF₂)₄COOH] were phase I metabolites in soybean. At the end of exposure, 5:3 FTCA (5.08 mol%), PFHxA (2.34 mol%) and PFPeA (0.58 mol%) were three main metabolites in soybean-solution system. 5:3 FTCA was predominant in soybean roots and stems, while PFHxA was the most abundant product in leaves. PFBA [F(CF₂)₃COOH] and 4:3 FTCA [F(CF₂)₄CH₂CH₂COOH] detected in the hydroponic solution most-likely came from the transformation of 5:3 FTCA by root-associated microbes. Moreover, phase II metabolites of 6:2 FTOH were identified and monitored in soybean tissues. Alcohol dehydrogenase, aldehyde dehydrogenase and glutathione S-transferase were found to participate in 6:2 FTOH metabolism. Based on the phase I and phase II metabolism of 6:2 FTOH in soybean, this study for the first time provides evidences for the transformation pathways of 6:2 FTOH in plants.

The contamination of ground water with arsenic is a great public health concern. This paper discusses the possible formation mechanism of high As groundwater; identify the main influences of natural and anthropogenic factors on As occurrence in groundwater; and finally estimates As-induced potential health hazards in an intensive agricultural region, Datong Basin (Northern China). Our findings indicate that the predominant controlling factors of As in groundwater can be divided into natural factors and anthropogenic activities. Natural factors can be classified as natural potential source of As, environmental geological characteristics and hydrochemical conditions; anthropogenic activities are manifested in industrial coal mining, domestic coal burning, agricultural irrigation return flow and excessive application of fertilizers, and groundwater exploitation. Microbial and/or chemical reduction desorption of arsenate from Fe-oxide/hydroxide and/or clay minerals, As-bearing Fe-oxide/hydroxide reduction coupled with sulfate reduction, and competition with phosphorus are postulated to be the major process dominating As enrichment in the alkaline and anoxic groundwater. In addition, age-dependent human health risk assessment (HHRS) was performed, and high risk values reveal a high toxic and carcinogenic risk of As contaminate for population who is subject to the continuous and chronic exposure to elevated As.

High phosphorus (P) load and consequent algal bloom are critical issues because of their harmful effects to aquatic ecosystems. The organic phosphorus (Po) cycling and hydrolyzation pathway in the sediments of a hypereutrophic lake area with high algae biomass were investigated using stable isotopes (δ¹³C and δ¹⁵N) along with C/N ratios, a sequential extraction procedure, ³¹P NMR spectrum, and alkaline phosphatase activity (APA) was measured simultaneously. C/N ratios lower than 10 combined with lighter δ¹³C (−23.5 to −25.2‰) and δ¹⁵N values (3.7–9.5‰) indicated that endogenous algal debris contributed to the predominant proportions of P-containing organic matter in the sediments. Sequential extraction results showed that Po fractions decreased as nonlabile Po > moderately labile Po > biomass-Po. Decreasing humic-associated Po (HA-Po) in sediments downward suggested the degradation of high-molecular-weight Po compounds on the geological time scale to low-molecular-weight Po including fulvic-associated Po (FA-Po), which is an important source of labile Po in the sediment. An analysis of the solution ³¹P NMR spectrum analysis showed that important Po compound groups decreased in the order of orthophosphate monoesters > DNA-Po > phospholipids. The significant correlation indicated that orthophosphate monoesters were the predominant components of HA-Po. Rapid hydrolysis of labile orthophosphate diesters further facilitated the accumulation of orthophosphate monoesters in the sediments. Additionally, the simultaneously upward increasing trend demonstrated that APA accelerated the mineralization of Po into dissolved reactive phosphorus (DRP), which might feed back to eutrophication in algae-dominant lakes. The significantly low half-life time (T₁/₂) for important Po compound groups indicated faster metabolism processes, including hydrolysis and mineralization, in hypereutrophic lakes with high algae biomass. These findings provided improved insights for better understanding of the origin and cycling processes as well as management of Po in hypereutrophic lakes.

Despite growing concern about the occurrence of microplastics in aquatic ecosystems there is only rudimentary understanding of the pathways through which any adverse effects might occur. Here, we assess the effects of polystyrene microplastics (PS-MPs; <70 μm) on a common and widespread algal species, Chlorella sorokiniana. We used laboratory exposure to test the hypothesis that the lipids and fatty acids (FAs) are important molecules in the response reactions of algae to this pollutant. Cultivation with PS-MPs systematically reduced the concentration of essential linoleic acid (ALA, C18:3n-3) in C. sorokiniana, concomitantly increasing oleic acid (C18:1n-9). Among the storage triacylglycerols, palmitoleic and oleic acids increased at the expenses of two essential fatty acids, linoleic (LIN, C18:2n-6) and ALA, while PS-MPs had even more pronounced effects on the fatty acid and hydrocarbon composition of waxes and steryl esters. The FA composition of two major chloroplast galactolipids, monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), were affected implying changes in the conformational structure of photosynthetic complexes in ways that can impair the photosynthesis. These data reveal how exposure to polystyrene microplastics can modify the concentrations of lipid molecules that are important intrinsically in cell membranes, and hence the lipid bilayers that could form an important barrier between algal cellular compartments and plastics in the aquatic environment. Changes in lipid synthesis and fatty acid composition in algae could also have repercussions for food quality, growth and stressor resistance in primary consumers. We advocate further studies of microplastics effects on the lipid composition of primary producers, and of their potential propagation through aquatic food webs.

Mcr-1 and blaNDM₋₁ antibiotic resistance genes (ARGs) confer resistance to colistins and carbapenems, which are often antibiotics used as a last resort in tertiary care hospitals. Dissemination of these two ARGs in drinking water supply systems and their effect on healthy gut bacteria are poorly studied. In this study, the dissemination of mcr-1 and blaNDM₋₁ in a drinking water supply system, and their effect on the antibiotic resistance of mouse gut bacteria are explored.Metagenome analysis revealed that source water (Taipu river and Jinze reservoir) was polluted with ARGs. Mcr-1 and blaNDM₋₁ can be disseminated through the water distribution system. Even advanced water treatments (ozone and biological activated carbon (BAC)) could not effectively remove mcr-1 and blaNDM₋₁. Low concentrations of chloramine disinfectants in the water distribution system were not effective at limiting ARG abundance. Mobile genetic elements were also found to play a major role in the dissemination of ARGs via horizontal gene transfer (HGT) throughout the water supply system. Statistical analysis revealed that there was no effect of temperature on the abundance of mcr-1 and blaNDM₋₁ throughout the water supply system.A last resort ARG, mcr-1 can disseminate from drinking water to the healthy mouse gut. The presence of mcr-1 in a strain belonging to Enterococcus hirae, which is different from the strain belonging to the Bacillus cereus group isolated from drinking water, strongly supports the phenomena of HGT inside the gut.This research provides novel insights into the role of drinking water in disseminating ARGs to the gut and strongly suggests that drinking water may also play a major role apart from other factors known to be involved in the prevalence of last resort ARGs in the gut.