We apply convolutional neural network (CNN) model for estimating daily 24-h averaged ground-level PM2.5 of the conterminous United States in 2011 by incorporating aerosol optical depth (AOD) data, meteorological fields, and land-use data. Unlike some of the recent supervised learning-based approaches, which only utilized the predictors from the location of which PM2.5 value is estimated, we naturally aggregate predictors from nearby locations such that the spatial correlation among the predictors can be exploited. We carefully evaluate the performance of our method via overall, temporally-separated, and spatially-separated cross-validations (CV) and show that our CNN achieves competitive estimation accuracy compared to the recently developed baselines. Furthermore, we develop a novel predictor importance metric for our CNN based on the recent neural network interpretation method, Layerwise Relevance Propagation (LRP), and identify several informative predictors for PM2.5 estimation.

Recently, chemical compounds containing lanthanides were used in various fields of biology and medicine. It has been described that such compounds can be applied in scanning electron microscopy (SEM) to increase the contrast and simplify the sample preparation process due to the process of replacing calcium with lanthanides in cell. However cell death by different mechanisms under influence of lanthanides seems possible. Here, we described that mummification process is a cell death physiologically realized in time: some time after lanthanide contrasting, the cell remains metabolically active and is able to biochemically transform neodymium-containing contrast, oxidize it and form large agglomerates. A distinctive feature of mummification induced by neodymium-containing contrast (NCC) is the formation of a high-rigid oxygen-containing “shield” on the surface of a neutrophil granulocyte.

In situ immobilization of heavy metals in contaminated soils using industrial by-products is an attractive remediation technique. In this work, titanium gypsum (TG) was applied at two levels (TG-L: 0.15% and TG-H: 0.30%) to simultaneously reduce the uptake of cadmium (Cd), lead (Pb) and arsenic (As) in rice grown in heavy metal contaminated paddy soils. The results showed that the addition of TG significantly decreased the pH and dissolved organic carbon (DOC) in the bulk soil. TG addition significantly improved the rice plants growth and reduced the bioavailability of Cd, Pb and As. Particularly, bioavailable Cd, Pb and As decreased by 35.2%, 38.1% and 38.0% in TG-H treatment during the tillering stage, respectively. Moreover, TG application significantly reduced the accumulation of Cd, Pb and As in brown rice. Real-time PCR analysis demonstrated that the relative abundance of sulfate-reducing bacteria increased with the TG application, but not for the iron-reducing bacteria. In addition, 16S rRNA sequencing analysis revealed that the relative abundances of heavy metal-resistant bacteria such as Bacillus, Sulfuritalea, Clostridium, Sulfuricella, Geobacter, Nocardioides and Sulfuricurvum at the genus level significantly increased with the TG addition. In conclusion, the present study implied that TG is a potential and effective amendment to immobilize metal(loid)s in soil and thereby reduce the exposure risk of metal(loid)s associated with rice consumption.

To compare aquatic organisms’ responses to the toxicity of copper oxide (CuO) nanoparticles (NPs) with those of CuO microparticles (MPs) and copper (Cu) ions, a global metabolomics approach was employed to investigate the changes of both polar and nonpolar metabolites in microalga Chlorella vulgaris after 5-day exposure to CuO NPs and MPs (1 and 10 mg/L), as well as the corresponding dissolved Cu ions (0.08 and 0.8 mg/L). Unchanged growth, slight reactive oxygen species production, and significant membrane damage (at 10 mg/L CuO particles) in C. vulgaris were demonstrated. A total of 75 differentiated metabolites were identified. Most metabolic pathways perturbed after CuO NPs exposure were shared by those after CuO MPs and Cu ions exposure, including accumulation of chlorophyll intermediates (max. 2.4–5.2 fold), membrane lipids remodeling for membrane protection (decrease of phosphatidylethanolamines (min. 0.6 fold) and phosphatidylcholines (min. 0.2–0.7 fold), as well as increase of phosphatidic acids (max. 1.5–2.9 fold), phosphatidylglycerols (max. 2.2–2.3 fold), monogalactosyldiacylglycerols (max. 1.2–1.4 fold), digalactosylmonoacylglycerols (max. 1.9–3.8 fold), diacylglycerols (max. 1.4 fold), lysophospholipids (max. 1.8–3.0 fold), and fatty acids (max. 3.0–6.2 fold)), perturbation of glutathione metabolism induced by oxidative stress, and accumulation of osmoregulants (max. 1.3–2.6 fold) to counteract osmotic stress. The only difference between metabolic responses to particles and those to ions was the accumulation of fatty acids oxidation products: particles caused higher fold changes (particles/ions ratio 1.9–3.0) at 1 mg/L and lower fold changes (particles/ions ratio 0.4–0.7) at 10 mg/L compared with ions. Compared with microparticles, there was no nanoparticle-specific pathway perturbed. These results confirm the predominant role of dissolved Cu ions on the toxicity of CuO NPs and MPs, and also reveal particle-specific toxicity from a metabolomics perspective.

The potential risks of phthalates affecting human and animal health as well as the environment are emerging as serious concerns worldwide. However, the mechanism by which phthalates induce developmental effects is under debate. Herein, we found that embryonic exposure of zebrafish to di-(2-ethylhexyl) phthalate (DEHP) and di-butyl phthalate (DBP) increased the rate of heart defects including abnormal heart rate and pericardial edema. Changes in the transcriptional profile demonstrated that genes involved in the development of the heart, such as tbx5b, nppa, ctnt, my17, cmlc1, were significantly altered by DEHP and DBP at 50 μg/L, which agreed with the abnormal cardiac outcomes. Methylated DNA immunoprecipitation sequencing (MeDIP-Seq) further showed that significant hypomethylation of nppa and ctnt was identified after DEHP and DBP exposure, which was consistent with the up-regulation of these genes. Notably, hypermethylation on the promoter region (<1 kb) of tbx5b was found after DEHP and DBP exposure, which might be responsible for its decrease in transcription. In conclusion, phthalates have the potential to induce cardiac birth defects, which might be associated with the transcriptional regulation of the involved developmental factors such as tbx5b. These findings would contribute to understand the molecular pathways that mediated the cardiac defects caused by phthalates.

Humic acid (HA) plays vital roles in regulating the environmental behaviors of metals and thus their toxicity to biota. However, the inner relation between metal bioavailability to soil organisms and the presence of HA with different molecular weight (Mw) is not well documented. In this study, we separated HAs into four fractions with Mw range of 5-30k Da, and discussed their ability to alleviating the toxicity of Cd and Pb to earthworm. The bioaccumulation capacities (Cₘₐₓ) increased in order of: UF1<UF2<UF3<UF4, which is in line with the variations of bioavailable concentrations of Cd and Pb in soil. Variations of Mw and binding capacities of HA determine the accumulation behavior in soil solution. The unsatisfactory of biotic ligand model fitting and the differences in fractions of the total biotic ligand sites (f) in earthworm bound by Cd and Pb suggested that only free species of Cd could be considered as biological available to earthworm, while the Pb–HAs complexes have potential ability to interact with earthworm membrane. Antioxidant enzymes are effective biomarkers, and HA with lower Mw play more important roles in restricting the toxicity of soil Cd and Pb to earthworm. These results reveal the different mechanism for HA controlling metal bioavailability between Cd and Pb in soil environment.

Clinical or pathological evidence demonstrated that air pollution could undermine other organ systems of human body besides respiratory and circulation systems. Investigations that directly relate hospital outpatient visits for endocrine (ENDO), digestive (DIGE), urological (UROL), and dermatological (DERM) diseases categories with ambient particulate matter (PM) are still lacking, particularly in heavily polluted cities. Here, we conducted a time-series analysis using 812,624, 1,111,342, 539,803, and 741,662 hospital visits for ENDO, DIGE, UROL, and DERM, respectively, in Nanjing, China from 2013 to 2019. A generalized additive model was applied to estimate the exposure-response associations. Results showed that a 10 μg/m³ increase in PM₂.₅ concentration on lag 0 day was significantly associated with 0.59% (95% CI: 0.30%, 0.88%), 0.43% (0.15%, 0.70%), 0.36% (0.06%, 0.66%), and 0.65% (0.42%, 0.87%) increase for ENDO, DIGE, UROL, and DERM hospital visits, respectively. The estimated effects of PM₁₀ were slightly smaller but still statistically significant. The magnitude and significance of the associations between PM and four health outcomes were sensitive to additional adjustment for co-pollutants. Exposure-response relationships were linear for PM concentrations lower than 100 μg/m³ but the curves became nonlinear across the full range of exposures due to a flatten slope at higher concentrations. We also explored the effect modifications by season (cold or warm), age (5–18, 18–64, 65–74, or 75+ years), and sex (male or female). Results showed that the DERM-related population aged 65 years or older was more vulnerable to PM exposure, compared with the 5 to 17-year age group; the DERM-related population aged 75 years or older and 65 years or older was more vulnerable to PM₂.₅ and PM₁₀ exposure, respectively, compared with the 18 to 64-year age group. Our study provided suggestive evidence that ambient PM pollution was associated with ENDO, DIGE, UROL, and DERM outpatient hospital visits in Nanjing, China.

Efficient elimination of As(V) and Sb(V) from wastewater streams has long been a major challenge. Herein, sulfide-modified α-FeOOH adsorbent was fabricated via a simple sulfidation reaction for removing As(V) and Sb(V) from aqueous media. Compared with the pristine α-FeOOH, sulfide-modified α-FeOOH increased the adsorption of As(V) from 153.8 to 384.6 mg/g, and Sb(V) adsorption from 277.8 to 1111.1 mg/g. The enhanced adsorption of both As(V) and Sb(V) was maintained at the pH range from 2 to 11, and was not interfered by various coexisting anions such as Cl⁻, SO₄²⁻, NO₃⁻, SiO₃²⁻ and PO₄³⁻. The adsorption affinity increased from 0.0047 to 0.0915 and 0.0053 to 0.4091 for As(V) and Sb(V), respectively. X-ray photoelectron spectroscopic investigation demonstrated a reductive conversion of As(V) to As(III) during the adsorption process with sulfide-modified α-FeOOH, but with no obvious variation of Sb(V) speciation. While the removal mechanism for As(V) was reduction followed by adsorption via hydroxyl groups, mainly surface complexation was involved in the removal of Sb(V). This study presented a simple strategy to enhance the adsorption capacity and adsorption affinity of α-FeOOH toward As(V)/Sb(V) via sulfide-modification.

Ingestion of lead (Pb) derived from ammunition used in the hunting of game animals is recognised to be a significant potential source of Pb exposure of wild birds, including birds of prey. However, there are only limited data for birds of prey in Europe regarding tissue concentrations and origins of Pb. Eurasian buzzards (Buteo buteo) found dead in the United Kingdom during an 11-year period were collected and the concentrations of Pb in the liver and femur were measured. Concentrations in the liver consistent with acute exposure to Pb were found in 2.7% of birds and concentration in the femur consistent with exposure to lethal levels were found in 4.0% of individuals. Pb concentration in the femur showed no evidence of consistent variation among or within years, but was greater for old than for young birds. The Pb concentration in the liver showed no effect of the birds’ age, but varied markedly among years and showed a consistent tendency to increase substantially within years throughout the UK hunting season for gamebirds. The resemblance of the stable isotope composition of Pb from buzzard livers to that of Pb from the types of shotgun ammunition most widely-used in the UK increased markedly with increasing Pb concentration in the liver. Stable isotope results were consistent with 57% of the mass of Pb in livers of all of the buzzards sampled being derived from shotgun pellets, with this proportion being 89% for the birds with concentrations indicating acute exposure to Pb. Hence, most of the Pb acquired by Eurasian buzzards which have liver concentrations likely to be associated with lethal and sublethal effects is probably obtained when they prey upon or scavenge gamebirds and mammals shot using Pb shotgun pellets.

River sediments contain environmental fingerprints that provide useful ecological information. However, the geochemistry of River Atuwara sediments has received less attention over the years. One hundred and twenty-six sediments from 21 locations were collected over a two-season period from River Atuwara, and a detailed investigation of the land use and land cover (LULC) change between 1990 and 2019, analysis of selected toxic and potentially toxic metal(oid)s (TPTM) (Cu, As, Cd, Pb, Ni, Cr, Zn, Fe, Co and Al) using ICP-OES, pollution index assessment, potential source identification (using center log-transformation approach), potential ecological, and human health risk assessment were conducted. The results of the LULC change revealed that the built-up area increased by 95.58 km², at an average rate of 3.186 km²/year over the past 30 years. The mean concentration of metal(oid)s increased in the order of Cd < As < Cr < Pb < Co < Ni < Cu < Zn < Fe < Al, and Cd < As < Cr < Co < Pb < Ni < Cu < Zn < Fe < Al during the dry and wet seasons, respectively. Meanwhile, the statistical analysis of the data spectrum inferred possible contamination from lithological and anthropogenic sources. According to the pollution load index, 90.48% of the sediment samples are polluted by the metal(oid)s. Potential ecological risk assessment identified Ni, As, and Cd as problematic to the ecological community of River Atuwara. Regarding the metal-specific hazard quotient via ingestion route, the risks are in order of Co ≫ As ≫ Pb > Cr > Cd > Al > Ni > Cu > Zn > Fe for both seasons and the carcinogenic risk for children via ingestion route presented a value higher than the safe limits for As, Cd, Cr, and Ni during both seasons. This outcome highlights the need for prompt action towards the restoration of environmental quality for communities surrounding River Atuwara.