Here we investigated the acute effects (12 h exposure) of three polystyrene nanoplastics (PS NPs, including PS, PS−COOH and PS−NH₂) on extracellular polymeric substance (EPS) composition of activated sludge. Three PS NPs exhibited the significant inhibition in total EPS and protein (PRO) production. The functional groups involved in the interactions between PS NPs and EPS were C-(C, H), and those between PS-NH₂ NPs and EPS were CO and O–C–O. In addition, the dewaterability of activated sludge were optimized by three PS NPs, especially PS-NH₂ NPs. Three PS NPs caused nonnegligible cellular oxidative stress and cell membrane damage in activated sludge (PS NPs exposure concentration: 100 mg/L). Among them, the cell membrane damage caused by PS-NH₂ was the most significant. Overall, the degree of influence on EPS and cytotoxicity of activated sludge varies with the surface functional groups of PS NPs.

Microplastics (MPs) are becoming a major concern due to their great potential to sorb and transport pollutants in the aquatic environment; hexabromocyclododecane (HBCD) is a common chemical additive in polystyrene (PS) MPs. However, the underlying mechanisms for the interaction of tetracycline (TC) onto HBCD-PS composites MPs (HBCD-PS MPs) are still not well documented. Our findings showed that the addition of HBCD resulted in a relatively higher hydrophobicity of PS MPs, and significantly enhanced the sorption ability of HBCD-PS MPs for TC. The kinetic models suggested that the sorption of TC onto PS and HBCD-PS MPs were mainly controlled by film diffusion and intra-particle diffusion, respectively. The statistical physics models were used to elucidate the sorption of TC onto PS and HBCD-PS MPs was associated with the formation of the monolayer, and the results indicated the TC was sorbed onto the two MPs by both multi-molecular and non-parallel processes. The TC sorption was solution pH-dependent while the effect of NaCl content on TC sorption was negligible. The presence of Cu(Ⅱ), Pb(Ⅱ), Cd(Ⅱ), and Zn(Ⅱ) ions had different influences on the TC sorption onto both the MPs. Overall, various mechanisms including π-π and hydrophobic interactions jointly regulated the sorption of TC onto both the MPs. Our results provided new insights into the sorption behavior and interaction mechanisms of TC onto both the MPs and highlighted that the addition of HBCD likely increased the enrichment capacity of MPs for pollutants in the environment.

In this study, municipal solid waste incineration fly ash (MSWIFA) was first washed (pretreatment) with pure water with liquid to solid (L/S) ratio of 2, 3, 6, 10, to understand the removal efficiency of chlorine and sulphate, as well as its consequent ability as alkaline activator for granulated blast furnace slag (GGBFS). Washed MSWIFA was blended with GGBFS at a fixed ratio of 3:7 to examine their impact on mechanical properties, reaction mechanism, microstructure and leaching behavior. The results showed that chlorine in MSWIFA (>70%) can be washed out easily, while the removal of sulphate was largely depended on the L/S. GGBFS can be better activated by a low L/S (e.g. 2) washed-MSWIFA with attaining the compressive strength of 45.2MPa at 28 days. The higher chlorine and sulphate contents retained in the washed-MSWIFA, the higher the total heat release in the activated GGBFS system. Calcium silicate hydrate (C–S–H), ettringite (AFt) and Friedel’s salt were the main hydration products of the activated binders. The rapid formation of AFt was mainly responsible for the 1-day strength development. Large amounts of Friedel’s salts were formed from 1 day to 3 days associated to the inhibition of sulphate, and the presence of C–S–H played the key role in long-term strength development. The leaching test of heavy metals and soluble ions also demonstrated that washed MSWIFA activated GGBFS binders were harmless to the environment.

In this study, the occurrence of aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN) and some of their metabolites were assessed in breast milk and urine of lactating women (N = 74) from Pirassununga, São Paulo, Brazil. Exposure estimations through urinary mycotoxin biomarkers was also performed. Samples were collected in four sampling times (May and August 2018, February and July 2019) and analyzed by liquid chromatography coupled to tandem mass spectrometry. Aflatoxin M₁ (AFM₁) was not detected in breast milk. However, two samples (3%) presented FB₁ at 2200 and 3400 ng/L, while 4 samples (5%) had OTA at the median level of 360 ng/L. In urine, AFM₁ and aflatoxin P₁ (AFP₁) were found in 51 and 11% of samples, respectively (median levels: 0.16 and 0.07 ng/mg creatinine, respectively). Urinary DON (median level: 38.59 ng/mg creatinine), OTA (median level: 2.38 ng/mg creatinine) and ZEN (median level: 0.02 ng/mg of creatinine) were quantified in 18, 8 and 10% of the samples, respectively. Mean probable daily intake (PDI) values based on urinary biomarkers were 1.58, 1.09, 5.07, and 0.05 μg/kg body weight/day for AFM₁, DON, OTA, and ZEN, respectively. Although a low mycotoxin occurrence was detected in breast milk, the PDI for the genotoxic AFs was much higher than those reported previously in Brazil, while PDI values obtained for OTA and DON were higher than recommended tolerable daily intakes. These outcomes warrant concern on the exposure of lactating women to these mycotoxins in the studied area.

Copper mine tailings are causing great environmental concern nowadays due to their high contents of heavy metals. These hazards may release to air, water, and soil, posing great threat to the living organisms in the surroundings. In the present work, we profiled the heavy metal contents, microbiome and resistome of a mine tailing in Dexing Copper Mine, which is the largest open-pit copper mine in China. A total of 39.75 Gb clean data was generated by metagenomics sequencing and taxonomy analysis revealed Actinobacteria, Proteobacteria, Acidobacteria, Euryarchaeota, and Nitrospirae as the most abundant phylum in this tailing. In general, 76 heavy metal resistance genes (HMRGs) and 194 antimicrobial resistance genes (ARGs) were identified with merA and rpoB2 as the most abundant HMRG and ARG, respectively. We also compared the differences of heavy metal concentrations among the six sampling sites in the same tailing and found that significant differences exited in copper and zinc. Hierarchical cluster analysis showed that the samples from the six sampling sites were clustering in two groups based on heavy metal concentrations. Accordingly, clustering based on microbial composition and relative abundances of resistance genes exhibited the same clustering pattern, indicating a possible shaping influence of heavy metals on the microbiome and resistome in this tailing. Our work presented heavy metal contents, microbial composition and resistance genes in a copper mine tailing of the largest copper mine in China, and these data will of great use in the surveillance, maintenance, and remediation of this tailing.

Zearalenone (ZEN), a mycotoxin with endocrine disruptive activity and oxidative stress generating ability, has been a worldwide environmental concern for its prevalence and persistency. However, the long-term effect of ZEN on aging process is not fully elucidated. Thus, the present study applied the Caenorhabditis elegans model to investigate the aging-related toxic effect and possible underlying mechanisms under prolonged and chronic ZEN exposure. Our results showed that locomotive behaviors significantly decreased in ZEN (0.3, 1.25, 5, 10, 50 μM) treated C. elegans. In addition, lifespan and aging markers including pharyngeal pumping and lipofuscin were also adversely affected by ZEN (50 μM). Furthermore, ZEN (50 μM) increased ROS level and downregulated antioxidant genes resulted from inhibition of nuclear DAF-16 translocation in aged C. elegans, which was further confirmed by more significant aging-related defects observed in ZEN treated daf-16 mutant. In conclusion, our findings suggest that the aging process and aging-related decline were induced by long-term exposure of ZEN in C. elegans, which is associated with oxidative stress, inhibition of antioxidant defense, and transcription factor DAF-16/FOXO.

PM₂.₅ (particles matter smaller aerodynamic diameter of 2.5 μm) exposure, a major environmental risk factor for the global burden of diseases, is associated with high risks of respiratory diseases. Heme-oxygenase 1 (HMOX1) is one of the major molecular antioxidant defenses to mediate cytoprotective effects against diverse stressors, including PM₂.₅-induced toxicity; however, the regulatory mechanism of HMOX1 expression still needs to be elucidated. In this study, using PM₂.₅ as a typical stressor, we explored whether microRNAs (miRNAs) might modulate HMOX1 expression in lung cells. Systematic bioinformatics analysis showed that seven miRNAs have the potentials to target HMOX1 gene. Among these, hsa-miR-760 was identified as the most responsive miRNA to PM₂.₅ exposure. More importantly, we revealed a “non-conventional” miRNA function in hsa-miR-760 upregulating HMOX1 expression, by targeting the coding region and interacting with YBX1 protein. In addition, we observed that exogenous hsa-miR-760 effectively elevated HMOX1 expression, reduced the reactive oxygen agents (ROS) levels, and rescued the lung cells from PM₂.₅-induced apoptosis. Our results revealed that hsa-miR-760 might play an important role in protecting lung cells against PM₂.₅-induced toxicity, by elevating HMOX1 expression, and offered new clues to elucidate the diverse functions of miRNAs.

The accuracy of the nitrogen (N) budget is of great importance for evidence-based decision-making to address both food security and environmental protection challenges. This study attempts to advance understanding of uncertainties in China's N budget using the Coupled Human And Natural Systems (CHANS) model and Monte Carlo simulation from 1980 to 2018. Results show that the spatial and temporal variations in agricultural and industrial activities and insufficient knowledge on N cycling parameterization are the two dominant causes of uncertainties in the N budget in China. Uncertainties of N inputs generally are <10%, while they are <30% for N outputs and >30% for N accumulations. Uncertainty of nitrogen oxides emission is more sensitive to energy consumption due to the large contributions from industry and transportation. While the uncertainty of ammonia emission is predominantly affected by agricultural activity. Combining surface measurements, satellite observations, and atmospheric simulation models enables cross-check of N fluxes in multiple systems and reduces uncertainties of N budget.

Sete Cidades Lake (São Miguel Island, Portugal) is subdivided into two interconnected branches: the Green Lake and Blue Lake. The lake has an area and maximum depth of 4.39 km² and 29.5 m (Blue Lake), respectively, with evidence of eutrophication, particularly in the northern area of the Green Lake. In this study, we conducted a sampling survey during January 2017 to measure CO₂ fluxes from the lake using a floating accumulation chamber. We also produced two hydrogeochemical profiles for each of the lake’s branches. A total of 1760 CO₂ flux measurements were taken along the lake’s surface. The lake water was relatively cold (14.0 °C on average) and weakly mineralised (average electrical conductivity of 116 μS cm⁻¹) with a neutral pH (7.7 on average). The relative composition of major ions occurred in the following decreasing order: Na⁺ > Mg²⁺ > Ca²⁺ > K⁺ for cations and Cl⁻ > HCO₃⁻ > SO₄²⁻ for anions. The lake water was mainly the Na–Cl type due to sea salt input from seawater spraying. CO₂ fluxes ranged from 0.3 to 17.2 g m⁻² d⁻¹ and from 2.1 to 17.9 g m⁻² d⁻¹ for the Blue and Green Lakes, respectively. Highest CO₂ degassing occurred in areas dominated by macrophytes and algal blooms. The measured values suggest that the CO₂ was predominantly biogenically sourced, which was further supported by the δ¹³C isotopic data. The estimated total CO₂ emissions varied between 5.8 t d⁻¹ (Green Lake; area = 0.81 km²) and 24.9 t d⁻¹ (Blue Lake; area = 3.58 km²). This study further elucidates the lake’s trophic and chemical pollution status and has major implications for lacustrine CO₂ emissions to the atmosphere. Our study also provides a reference for understanding potential future variations in volcanic activity.

Recent studies suggests that air pollution, from among others road traffic, can influence growth and development of the human foetus during pregnancy. The effects of air pollution from heavy industry on birth outcomes have been investigated scarcely.Our aim was to investigate the associations of air pollution from heavy industry on birth outcomes.A cross-sectional study was conducted among 4488 singleton live births (2012–2017) in the vicinity of a large industrial area in the Netherlands. Information from the birth registration was linked with a dispersion model to characterize annual individual-level exposure of pregnant mothers to air pollutants from industry in the area. Associations between particulate matter (PM₁₀), nitrogen oxides (NOX), sulphur dioxide (SO₂), and volatile organic compounds (VOC) with low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA) were investigated by logistic regression analysis and with gestational age, birth weight, birth length, and head circumference by linear regression analysis.Exposures to NOX, SO₂, and VOC (per interquartile range of 1.16, 0.42, and 0.97 μg/m³ respectively) during pregnancy were associated with LBW (OR 1.20, 95%CI 1.06–1.35, OR 1.20, 95%CI 1.00–1.43, and OR 1.21, 95%CI 1.08–1.35 respectively). NOX and VOC were also associated with PTB (OR 1.14, 95%CI 1.01–1.29 and OR 1.17, 95%CI 1.04–1.31 respectively). Associations between exposure to air pollution and birth weight, birth length, and head circumference were statistically significant. Higher exposure to PM₁₀, NOX, SO₂ and VOC (per interquartile range of 0.41, 1.16, 0.42, and 0.97 μg/m³ respectively) was associated with reduced birth weight of 21 g to 30 g.The 90th percentile industry-related PM₁₀ exposure corresponded with an average birth weight decrease of 74 g.