The measurement of aerosols (PM₁.₀ and PM₂.₅) was conducted during 2016 and 2017 in Beijing, Tangshan and Shijiazhuang, investigating the spatial and temporal variations of aerosols and major chemical components. The WRF-Chem model was applied to simulate the impacts of aerosol direct and semi-direct feedbacks on meteorological factors and identify the source of PM₂.₅. The results showed that the average annual concentrations were 63.3–88.7 μg/m³ for PM₁.₀ and 81.3–112 μg/m³ for PM₂.₅ at the three study cities, and the average seasonal concentration ratios of PM₁.₀/PM₂.₅ ranged from 64.3% to 86.0%. PM₁.₀ and PM₂.₅ showed a good correlation that the squared correlation coefficients were all higher than 0.9, indicating both mainly came from the same emission sources. Water-soluble inorganic ions and carbonaceous components were major chemical species in PM₁.₀ and PM₂.₅, accounting for 48.9%–54.1% and 25.6%–27.8% in PM₁.₀, 48.1%–52.3% and 22.7%–24.7% in PM₂.₅. Those chemical species showed spatially similar characteristics but pronounced seasonal differences, with higher concentrations in autumn and winter, lower in spring and summer. Aerosol feedbacks had different effects on various meteorological factors. Three study cities monthly-mean incoming solar radiation decreased by 40.6 W/m², 82.2 W/m², 38.4 W/m², and 49.9 W/m²; planetary boundary layer height reduced by 54.0 m, 109 m, 32.2 m and 85.2 m; temperature at 2 m decreased by 0.5 °C, 0.8 °C, 0.5 °C and 1.3 °C; relative humidity increased by 1.5%, 2.6%, 1.3% and 4.7% in April, July, October and January, respectively, while wind speed changes were relatively smaller than above factors. Additionally, the major sources of PM₂.₅ in January were identified as transportation in Beijing, while industrial and domestic sources in Tangshan and Shijiazhuang. The obtained results will provide more in-depth and comprehensive understanding of aerosol pollution and management strategies.

Application of controlled release urea (CRU) is recommended to reduce the undesirable environmental effects resulting from urea application. However, the overall effects of CRU on maize productivity and reactive nitrogen (N) losses remain unclear. Our global meta-analysis based on 866 observations of 120 studies indicated that application of CRU instead of urea (same N rate) increased maize yield by 5.3% and nitrogen use efficiency (NUE) by 24.1%, and significantly decreased nitrous oxide (N₂O) emission, N leaching and ammonia (NH₃) volatilization by 23.8%, 27.1% and 39.4%, respectively. The increase of NUE and reduction of N₂O emission by CRU application were greater with medium and high N rates (150 ≤ N < 200 and N ≥ 200 kg N ha⁻¹) than with low N rates. The reduction in N₂O emission and N leaching with CRU application were enhanced when soil organic carbon (SOC) content was <15.0 g kg⁻¹, and soil texture was medium or coarse. The reduction in N₂O emission and NH₃ volatilization with CRU were greater in soils with pH ≥ 6.0. We concluded that use of CRU should be encouraged for maize production, especially on light-textured soils with low organic matter content.

Dairy cattle of different ages experience different living conditions and varied frequency of antibiotic administration that likely influence the distribution of microbiome and resistome in ways that reflect different risks of microbial transmission. To assess the degree of variance in these distributions, fecal and soil samples were collected from six distinct housing areas on commercial dairy farms (n = 7) in Washington State. 16S rRNA gene sequencing indicated that the microbiota differed between different on-farm locations in feces and soil, and in both cases, the microbiota of dairy calves was often distinct from others (P < 0.05). Thirty-two specific antibiotic resistance genes (ARGs) were widely distributed on dairies, of which several clinically relevant ARGs (including cfr, cfrB, and optrA) were identified for the first time at U.S. dairies. Overall, ARGs were observed more frequently in feces and soil from dairy calves and heifers than from hospital, fresh, lactation and dry pens. Droplet-digital PCR demonstrated that the absolute abundance of floR varied greatly across housing areas and this gene was enriched the most in calves and heifers. Furthermore, in an extended analysis with 14 dairies, environmental soils in calf pens had the most antibiotic-resistant Escherichia coli followed by heifer and hospital pens. All soil E. coli isolates (n = 1,905) are resistant to at least 4 different antibiotics, and the PFGE analysis indicated that florfenicol-resistant E. coli is probably shared across geographically-separated farms. This study identified a discrete but predictable distribution of antibiotic resistance genes and organisms, which is important for designing mitigation for higher risk areas on dairy farms.

While wastewater treatment plants have been identified as the most prominent source of emerging micropollutants in surface waters, prediction of their ambient concentrations remains a challenge. This is due to the variability of loads entering individual treatment plants and of the elimination capacity by the latter as well as potential attenuation in the river network. Although geospatially detailed models exist, they suffer from the same data input uncertainties. Here, we investigated the concentration profiles of 20 emerging pollutants in different river stretches in Luxembourg with variable sanitary pressures. Using carbamazepine as a recalcitrant wastewater indicator, the correlation of the compounds to the latter revealed source and fate variability as well as specific emitters. Relating carbamazepine to sanitary pressure, expressed as the sum of population equivalents in a catchment divided by its surface [PE ha⁻¹] allowed predicting the impact of emerging pollutants on the entire river network. The limited variability of the pollutant profiles allowed for prioritization of impacted stretches depending on the different sanitary pressures at risk quotient exceedance. The main drivers of impact were triclosan, diclofenac, clarithromycine and diuron.

Glyphosate, as a broad-spectrum herbicide, is frequently detected in water and several studies have investigated its effects on several freshwater aquatic organisms. Yet, only few investigations have been performed on marine macroalgae. Here, we studied both the metabolomics responses and the effect on primary production in the endemic brown algae Fucus virsoides exposed to different concentration (0, 0.5, 1.5 and 2.5 mg L⁻¹) of a commercial glyphosate-based herbicide, namely Roundup®. Our results show that Roundup® significantly reduced quantum yield of photosynthesis (Fᵥ/Fₘ) and caused alteration in the metabolomic profiles of exposed thalli compared to controls. Together with the decrease in the aromatic amino acids (phenylalanine and tyrosine), an increase in shikimate content was detected. The branched-amino acids differently varied according to levels of herbicide exposure, as well as observed for the content of choline, formate, glucose, malonate and fumarate. Our results suggest that marine primary producers could be largely affected by the agricultural land use, this asking for further studies addressing the ecosystem-level effects of glyphosate-based herbicides in coastal waters.

Light at night (LAN) negatively impacts the behaviour and physiology; however, very little is known about molecular correlates of LAN-induced effects in diurnal animals. Here, we assessed LAN-induced effects on behaviour and physiology, and examined molecular changes in the liver of diurnal zebra finches (Taeniopygia guttata). Birds were exposed to dim LAN (dLAN: 12L = 150 lux: 12D = 5 lux), with controls on 12L (150 lux): 12D (0 lux). dLAN altered daily activity-rest and eating patterns, induced nocturnal eating and caused body fattening and weight gain, and reduced nocturnal melatonin levels. Concomitant increased nighttime glucose levels, decreased daytime thyroxine and triglycerides levels, and hepatic lipid accumulation suggested the impairment of metabolism under dLAN. Transcriptional assays evidenced dLAN-induced negative effects on metabolism in the liver, the site of metabolic homeostasis. Particularly, increased g6pc and foxo1 mRNA expressions suggested an enhanced gluconeogenesis, while increased egr1 and star expressions suggested enhanced cholesterol biosynthesis and lipid metabolism, respectively. Similarly, overexpressed sirt1 indicated protection from the metabolic damage due to elevated gluconeogenesis and cholesterol biosynthesis under dLAN. However, no effect on genes involved in lipogenesis (fasn) and insulin signalling pathway (socs3 and insig1) might indicate for the post transcriptional/post translational modification effects or the involvement of other genetic pathways in LAN-induced effects. We also found daily rhythm in the hepatic expression of selected clock and clock-controlled genes (per2, bmal1 and reverb-beta), with an elevated mesor and amplitude of per2 oscillation, suggesting a role of per2 in the liver metabolism. These results demonstrate dLAN-induced negative effects on the behaviour and physiology, and provide molecular insights into metabolic risks of the exposure to illuminated nights to diurnal animals including humans in an urban setting.

Few studies have reported the association between greenspace and academic performance at school level. We examined associations between both residential and school greenspace and individual school grades in German adolescents.German and maths grades from the latest school certificate, residential and school greenspace, and covariates were available for 1351 10 and 15 years old Munich children and 1078 Wesel children from two German birth cohorts – GINIplus and LISA. Residential and school greenspace was assessed by the Normalized Difference Vegetation Index (NDVI), tree cover, and (in Munich only) proportion of agricultural land, forest, and urban green space in 500-m and 1000-m circular buffers. Longitudinal associations between each exposure-outcome pair were assessed by logistic mixed effects models with person and school as random intercepts and adjusted for potential confounders.No associations were observed between any of the greenspace variables and grades in Wesel children. Several statistically significant associations were observed with German and maths grades in Munich children, however associations were inconsistent across sensitivity analyses.There is no evidence of an association of higher greenspace at residence, school or combined with improved academic performance in German adolescents from the GINIplus and LISA longitudinal studies.

Sulfide-rich tailings produced by mineral processing are prone to oxidation and cause many pollution problems in the surrounding environment; therefore, this issue has become a focus of attention. The Tongling Shuimuchong tailings reservoir contains a large amount of sulfide minerals, especially pyrrhotite and pyrite. This reservoir features obvious oxidation in the surface layer, and the slab is very hard. Mineralogical and environmental geochemical analyses were performed on tailings with different degrees of oxidation in the Shuimuchong tailings reservoir to investigate the influence of the formation of the hard oxidized layer on environmental pollution in the tailings pond. The samples were first subjected to particle-size analysis. The shallow tailings were mainly composed of medium particle; the proportions of coarse particle and fine tailings particles were equal; and the proportions of clay and silt were less than those of the other size fractions. Mineralogical analysis showed that pyrrhotite and pyrite were replaced by residual structures in the oxide layer. The secondary minerals goethite, hematite and jarosite were attached to the edges and fractures of sulfide minerals. The samples were geochemically analyzed to determine the total concentrations of 5 elements, the pH and the major anions. The maximum SO₄²⁻ concentrations of 33,970 and 32,749 mg/kg were observed at a depth of 40 cm in profiles 1 and 2, respectively. Metal sulfide mineral oxidation in the tailings lowered the pH of the materials to values less than 4. The concentration of HCO₃⁻ (122–635 mg/kg) in the tailings samples was very low, and the concentration of CO₃²⁻ was zero. As (53.2–133.7 mg/kg), Pb (24.2–307.5 mg/kg) and Hg (0.03–0.06 mg/kg) were concentrated in the highly oxidized layer at the surface; the Cd content (0.23–10.5 mg/kg) increased with decreasing oxidation degree of the tailings; and the Cr content (38.0–54.9 mg/kg) fluctuated around a certain value.

Data from National Health and Nutrition Examination Survey for 2013–2016 were used to compare observed levels of cadmium, lead, and total mercury in blood among US residents aged ≥12 years who were users of cigars, cigarettes, cigars and cigarettes, e-cigarettes and dual users of cigarettes and e-cigarettes. Total sample size available for analysis was 1139. Adjusted geometric means (AGM) among cigarette, cigar, e-cigarette, cigarette and cigar, and cigarette-e-cigarette users were comparable for blood cadmium lead, and total mercury. Cigar only users had lower AGM than cigar and cigarette users for total mercury (0.56 vs. 0.97 μg/L, p = 0.03). There is no evidence yet that can show concentrations of blood and urine cadmium, lead, and mercury among e-cigarette users are any different than among cigarette and/or dual users of cigarettes and e-cigarettes.

Heavy metal stress in soil accelerates the plant root exudation of organic ligands. The degradation of exudate ligands can be fundamental to controlling the complexation of heavy metals. However, this process remains poorly understood. Here, we investigated the relationship between the transformation of glycine, a representative amino acid exudate, and cadmium/lead mobility in soils. Two 48-h incubation experiments were conducted after glycine addition to the soils. Parameters related to glycine distribution and degradation, Cd/Pb mobility, and the formation of glycine-Cd complex were analyzed. Glycine addition gradually decreased the Cd and Pb mobility throughout the 48-h incubation. By the end of the experiment, the CaCl₂-extracted Cd and Pb concentrations decreased by 63.5% and 43.6%, respectively. The glycine mineralization was strong in the first 6 h, as indicated by a sharp decrease in CO₂ efflux rates from 10.04 ± 0.62 to 3.51 ± 0.07 mg C–CO₂ kg⁻¹ soil h⁻¹. The mineralization rates notably decreased after 6 h. The comparisons of dissolved organic carbon and hydrolyzable amino acid contents indicated that glycine mineralization in solution (95.6%) was much stronger than that in soil solids (49.3%). At the end of incubation, 0.22 mmol kg⁻¹ glycine remained in soil solids. The remaining glycine provided sufficient sorption sites for Cd²⁺ and Pb²⁺, resulting in enhanced metal fixation via complexation. Comparisons of zeta potentials supported the formation of the glycine-Cd complex. The Cd and Pb immobilization processes could be attributed to metal-glycine complex formation, sorption re-equilibrium, and glycine degradation. These findings emphasize that the biogeochemical processes of glycine, derived from root exudates or protein degradation products, increased the sorption of heavy metals to soils and thus reduced their toxicity to plants.