Open waste burning emissions constitute a significant source of air pollution affecting human health in India. In regions where cleaner fuels have displaced solid biofuel usage, open waste burning is rapidly becoming one of the largest sources of airborne human class-I-carcinogens and particulate matter. As the establishment of waste management infrastructure in rural India is likely to take years, we explore whether health-relevant emissions can be reduced by legalizing the burning of dry non-biodegradable waste in improved devices. We measure the emission factors of 76 VOCs, CH₄, CO, and CO₂ from different types of waste burned in two different improved devices, a burn basket and a local water heater. Based on our experiments, we create four “what-if” intervention scenarios to assess the improvement of air quality due to the emission reductions that can be accomplished by four management strategies. We find that substituting the traditional, more polluting water heating fuels with dry plastic waste across rural India can reduce primary emissions (e.g., −29 Ggy⁻¹ for benzene) and ozone formation potential (−2960 Ggy⁻¹) from open waste burning. When dry waste is used in lieu of more polluting fuels, and its burning serves a purpose, the net class-I-carcinogen benzene emissions, would be halved compared to the present. The change in emissions for the class-I carcinogen 1,3-butadiene would become net negative. This happens because the emissions avoided when part of the solid biofuel currently used in rural India is replaced by plastic waste (4.1 (1.2–4.1) Ggy⁻¹) exceed the waste burning emissions of this compound (3 (1.2–3.7) Ggy⁻¹) by so much, that residential sector emission reductions offset all waste burning emissions including those of landfill fires. Our study demonstrates that India's air quality can be improved by permitting and promoting the use of dry packaging waste in lieu of traditional biofuels and by promoting improved burning devices.

The adverse health effects associated with the inhalation and ingestion of naturally occurring radon gas produced during the uranium decay chain mean that there is a need to identify high-risk areas. This study detected radon-prone areas using a geographic information system (GIS)-based probabilistic and machine learning methods, including the frequency ratio (FR) model and a convolutional neural network (CNN). Ten influencing factors, namely elevation, slope, the topographic wetness index (TWI), valley depth, fault density, lithology, and the average soil copper (Cu), calcium oxide (Cao), ferric oxide (Fe₂O₃), and lead (Pb) concentrations, were analyzed. In total, 27 rock samples with high activity concentration index values were divided randomly into training and validation datasets (70:30 ratio) to train the models. Areas were categorized as very high, high, moderate, low, and very low radon areas. According to the models, approximately 40% of the study area was classified as very high or high risk. Finally, the radon potential maps were validated using the area under the receiver operating characteristic curve (AUC) analysis. This showed that the CNN algorithm was superior to the FR method; for the former, AUC values of 0.844 and 0.840 were obtained using the training and validation datasets, respectively. However, both algorithms had high predictive power. Slope, lithology, and TWI were the best predictors of radon-affected areas. These results provide new information regarding the spatial distribution of radon, and could inform the development of new residential areas. Radon screening is important to reduce public exposure to high levels of naturally occurring radiation.

The catalytic hydrogenolysis of a typical model compound of mulching film waste, polyethylene, was investigated as a potential way to improve economic efficiency of mulching film recycling. Nickel-based heterogeneous catalysts are proposed for polyethylene hydrogenolysis to produce liquid hydrocarbons. Among catalysts supported on various carriers, Ni/SiO₂ catalyst shows the highest activity which may due to the interactions between nickel and silica with the formation of nickel phyllosilicate. As high as 81.18% total gasoline and diesel range hydrocarbon was obtained from the polyethylene hydrogenolysis at relatively mild condition of 280 °C, and 3 MPa cold hydrogen pressure. The result is comparable to what have been reported in previous studies using noble metal catalysts. The gasoline and diesel range hydrocarbon are n-alkanes with a distribution at a range of C₄–C₂₂. The gas products are primarily CH₄ along with a small amount of C₂H₆ and C₃H₈. High yield of CH₄ as much as 9.68% was observed for the cleavage of molecule occurs along the alkane chain.

The combined effects of emerging pollutants and ocean acidification (OA) on marine organisms and marine ecosystems have attracted increasing attention. However, the combined effects of tralopyril and OA on marine organisms and marine ecosystems remain unclear. In this study, Crassostrea gigas (C. gigas) were exposed to tralopyril (1 μg/L) and/or OA (PH = 7.7) for 21 days and a 14-day recovery acclimation. To investigate the stress response and potential molecular mechanisms of C. gigas to OA and tralopyril exposure alone or in combination, as well as the effects of OA and/or tralopyril on bivalve biomineralization and marine carbon cycling. The results showed that the combined toxicity was between that of acidification and tralopyril alone. Single or combined exposure activated the general stress defense responses of C. gigas mantle, affected energy metabolism and biomineralization of the organism and the carbon cycle of the marine ecosystem. Moreover, acidification-induced and tralopyril-induced toxicity showed potential recoverability at molecular and biochemical levels. This study provides a new perspective on the molecular mechanisms of tralopyril toxicity to bivalve shellfish and reveals the potential role of tralopyril and OA on marine carbon cycling.

Microbial remediation is a potential remediation method for petroleum-contaminated soil. In order to explore the petroleum degradation mechanism by microorganisms, the oilfield soil was remedied by Acinetobacter baumannii combined with Talaromyces sp. The degradation mechanism was studied by analyzing soil microbial community and functional genes through metagenomics during the degradation process. The result showed the degradation rate of petroleum was 65.6% after 28 days. The concentration of petroleum decreased from 1220 mg/kg to 420 mg/kg. In the co-culture group, Acinetobacter baumannii became the dominant species, the annotated genes of it at the species level accounted for 7.34% while that of Talaromyces sp. accounted for only 0.34%. Meanwhile, the annotated genes of Bacillus, Halomonas, and Nitriliruptor at the genus level were up-regulated by 1.83%, 0.90%, and 0.71%, respectively. In addition, large functional genes were significantly up-regulated, including the peroxisome, P450 enzyme (CYP53, CYP116, CYP102, CYP645), and biofilm formulation, promoting the oxidation and hydroxylation, and catalyzing the epoxidation of aromatic and aliphatic hydrocarbons. Meanwhile, the degrading genes of alkanes and aromatic hydrocarbons were expressed promotionally, and degradation pathways were deduced. In conclusion, the inoculation of Acinetobacter baumannii combined with Talaromyces sp. accelerated the degradation of petroleum in oilfield soil and improved the growth of indigenous petroleum-degrading bacteria. Many functional genes related to petroleum degradation were promoted significantly. These results proved the co-culture of bacteria-fungi consortium contributes to the bioremediation of petroleum-contaminated soil.

Petroleum hydrocarbon pollution is a global problem. However, the effects of different petroleum pollution levels on soil microbial communities and ecological functions are still not clear. In this study, we analyzed the changes in microbial community structures and carbon and nitrogen transformation functions in oil-contaminated soils at different concentrations by chemical analysis, high-throughput sequencing techniques, cooccurrence networks, and KEGG database comparison functional gene annotation. The results showed that heavy petroleum concentrations (petroleum concentrations greater than 20,000 mg kg⁻¹) significantly decreased soil microbial diversity (p = 0.01), soil microbiome network complexity, species coexistence patterns, and prokaryotic carbon and nitrogen fixation genes. In medium petroleum contamination (petroleum concentrations of between 4000 mg kg⁻¹ and 20,000 mg kg⁻¹), microbial diversity (p > 0.05) and carbon and nitrogen transformation genes showed no evident change but promoted species coexistence patterns. Heavy petroleum contamination increased the Proteobacteria phylum abundance by 3.91%–57.01%, while medium petroleum contamination increased the Actinobacteria phylum abundance by 1.69%–0.26%. The results suggested that petroleum concentrations played a significant role in shifting soil microbial community structures, ecological functions, and species diversities.

People who relocate to a new environment may experience health effects from a change in ambient air pollution. We undertook a literature review of studies of such relocations and health effects and report the results as a narrative analysis. Fifteen articles of heterogeneous designs met the inclusion criteria. Four short-term (relocation duration less than six months) and three long-term (relocation duration six months or greater) studies reported evidence of the effect of relocation on physiological outcome, biomarkers or symptoms. All had potential weaknesses of design or analysis but, as a whole, their results are broadly consistent in suggesting short-term adverse effects of air pollutants or their reversibility. One long-term study provided evidence that changes in air pollution exposure during adolescence have a measurable effect on lung function growth. Four cohort studies were also identified that used relocation to strengthen evidence of air-pollution-exposure relationships by using a design that incorporates effective randomization of exposure or the use of relocation to improve exposure classification. However, three studies of relocation during pregnancy provided limited evidence to conclude an effect of relocation-related change in exposure on pregnancy outcome. Overall, most relocation studies are consistent with short- or long-term adverse effects of air pollution on biological function or mortality, but many studies of change in exposure have design weaknesses that limit the robustness of interpretation. We outline principles for improved design and analysis to help strengthen future studies for the insights they can provide from their quasi-experimental designs, including on the nature and timing of functional changes of relocation-related changes in exposure to ambient air pollution.

In recent years, the cardiovascular toxicity of urban fine particulate matter (PM₂.₅) has sparked significant alarm. Mitochondria produce 90% of ATP and make up 30% of the volume of cardiomyocytes. Thus knowledge of myocardial mitochondrial dysfunction due to PM₂.₅ exposure is essential for further cardiotoxic effects. Here, the mechanism of PM₂.₅-induced cardiac hypertrophy through calcium overload and mitochondrial dysfunction was investigated in vivo and in vitro. Male and female BALB/c mice were given 1.28, 5.5, and 11 mg PM₂.₅/kg bodyweight weekly through oropharyngeal inhalation for four weeks and were assigned to low, medium, and high dose groups, respectively. PM₂.₅-induced myocardial edema and cardiac hypertrophy were detected in the high-dose group. Mitochondria were scattered and ruptured with abnormal ultrastructural morphology. In vitro experiments on human cardiomyocyte AC16 showed that exposure to PM₂.₅ for 24 h caused opened mitochondrial permeability transition pore --leading to excessive calcium production, decreased mitochondrial membrane potential, weakened mitochondrial respiratory metabolism capacity, and decreased ATP production. Nevertheless, the administration of calcium chelator ameliorated the mitochondrial damage in the PM₂.₅-treated group. Our in vivo and in vitro results confirmed that calcium overload under PM₂.₅ exposure triggered mTOR/AKT/GSK-3β activation, leading to mitochondrial bioenergetics dysfunction and cardiac hypertrophy.

Dioecious plants show sexual differences in resistance traits to abiotic stresses. However, the effects of exogenous pesticide application on female and male plant growth and their associated adaptation mechanisms are unclear. Our study investigated the effects of the broad-spectrum pesticide lambda-cyhalothrin (λ-CY) on dioecious Populus cathayana growth and explored the factors through which λ-CY changed the rhizosphere bacterial community and physicochemical soil properties via sex-specific metabolomics. The sequential application of λ-CY significantly suppressed male shoot- and root biomass, with little effect on the growth of females. Females possessed a higher intrinsic chemo-diversity within their root exudates, and their levels of various metabolites (sugars, fatty acids, and small organic acids) increased after exposure to λ-CY with consequences on bacterial community composition. Maintaining high bacterial alpha diversity and recruiting specific bacterial groups slowed down the loss of rhizosphere nutrients in females. In contrast, the reduction in bacterial alpha diversity and network structure stability in males was associated with lower rhizosphere nutrient availability. Spearman's correlation analysis revealed that several bacterial groups were positively correlated with the root secretion of lipids and organic acids, suggesting that these metabolites can affect the soil bacterial groups actively involved in the nutrient pool. This study provided novel insights that root exudates and soil microbial interactions may mediate sex-specific differences in response to pesticide application.

Almost 81% of nitrogen fertilizers are applied in form of urea but most of it is lost due to volatilization and leaching leading to environmental pollution. In this regard, slow-release nano fertilizers can be an effective solution. Here, we have synthesized different Fe₃O₄-urea nanocomposites with Fe₃O₄ NPs: urea ratio (1:1, 1:2, 1:3) ie. NC-1, 2, and 3 respectively, and checked their efficacy for growth and yield enhancement. Oryza sativa L. cv. Swarna seedlings were treated with different NCs for 14 days in hydroponic conditions and significant up-regulation of photosynthetic efficiency and nitrogen metabolism were observed due to increased availability of nitrogen and iron. The discriminant functional analysis confirmed that the NC3 treatment yielded the best results so further gene expression studies were performed for NC-3 treated seedlings. Significant changes in expression profiles of ammonia and nitrate transporters indicated that NC-3 treatment enhanced nitrogen utilization efficiency (NUE) due to sustained slow release of urea. From pot experiments, we found significant enhancement of growth, grain nutrient content, and NUE in NC supplemented sets. 1.45 fold increase in crop yield was achieved when 50% N was supplemented in form of NC-3 and the rest in form of ammonium nitrate. NC supplementation can also play a vital role in minimizing the use of bulk N fertilizers because, when 75% of the recommended N dose was supplied in form of NC-3, 1.18 fold yield enhancement was found. Thus our results highlight that, slow-release NC-3 can play a major role in increasing the NUE of rice.