The short-term alteration of peripheral cytokines may be an early adverse health effect of PM₂.₅ exposure and may be further associated with cardiovascular disease. We conducted a randomized, double-blind crossover trial using true or sham air filtration among 54 healthy college students in Beijing to investigate the potential benefits of short-term indoor air filtration and the adverse health effects of time-weighted personal PM₂.₅ exposure through inflammatory cytokines. The participants randomly received true or sham air filtration intervention for a week, and the treatment was changed after a two-week washout period. Peripheral blood samples were collected after each intervention period to measure 38 inflammatory cytokines. A linear mixed-effects model was applied to estimate the impacts of air purification or a 10 μg/m³ PM₂.₅ exposure increase on cytokines. Lag effects of PM₂.₅ exposure were analyzed using single-day and moving average lag models. Air filtration reduced indoor and time-weighted average personal PM₂.₅ concentrations by 69.0% (from 33.6 to 10.4 μg/m³) and 40.3% (from 40.6 to 24.3 μg/m³), respectively. We observed a significant association of PM₂.₅ exposure with growth-regulated alpha protein (GRO-α) of −11.3% (95%CI: 17.0%, −5.4%). In the lag models, significant associations between personal PM₂.₅ exposure and interleukin-1 receptor antagonist (IL-1Ra), monocyte chemotactic protein (MCP-1), and eotaxin were obtained at lag0, while associations with cytokines including vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), fibroblast growth factor-2 (FGF-2), granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein-1β (MIP-1β), IL-4, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were noted at relatively long lagged exposure windows (lag5-lag6). No significant alteration in cytokines was observed under true air filtration intervention. Our study indicates the effectiveness of air filtration on indoor PM₂.₅ reduction. PM₂.₅ exposure may decrease GRO-α levels and change different cytokine levels time-varyingly. Further study is still needed to explore the mechanisms of PM₂.₅ exposure on the inflammatory response.

Coastal water quality in China has been impacted by direct discharge of industrial wastewater, and various kinds of AOX pollutants have been detected in the seawater and sediment. As the dominant pollution source of Hangzhou Bay, a typical fine chemical industry park “HSEDA” was selected as the study area in this research. The AOX in both wastewater and sludge phases from 22 large-scaled enterprises were simultaneously investigated. The results quantitatively illustrated the AOX flows from engineered wastewater and sludge treatment systems to natural environment. It can be seen that industrial enterprises discharged at least 160 t AOX every year, and about 105.4 t/a AOX eventually entered the natural environment. The dye manufacturing industry, which accounted for more than 60% of the total AOX emission load in HSEDA, was identified as the AOX pollution-intensive sector. The occurrence, characteristic pollutants and fate of AOX in dye wastewater were discussed, on the basis of which the improvements of cleaner production and wastewater treatment technologies have been put forward.

Nanotechnology has been recognized as the emerging field for the synthesis, designing, and manipulation of particle structure at the nanoscale. Its rapid development is also expected to revolutionize industries such as applied physics, mechanics, chemistry, and electronics engineering with suitably tailoring various nanomaterials. Inorganic nanoparticles such as silver nanoparticles (Ag-NPs) have garnered more interest with their diverse applications. In correspondence to green chemistry, researchers prioritize green synthetic techniques over conventional ones due to their eco-friendly and sustainable potential. Green-synthesized NPs have proven more beneficial than those synthesized by conventional methods because of capping by secondary metabolites. The present study reviews the various means being used by the researchers for the green synthesis of Ag-NPs. The morphological characteristics of these NPs as obtained from numerous characterization techniques have been explored. The potential applications of bio-synthesized Ag-NPs viz. Antimicrobial, antioxidant, catalytic, and water remediation along with the plausible mechanisms have been discussed. In addition, toxicity analysis and biomedical applications of these NPs have also been reviewed to provide a detailed overview. The study signifies that biosynthesized Ag-NPs can be efficiently used for various applications in the biomedical and industrial sectors as an environment-friendly and efficient tool.

Urban tree canopies are a significant sink for atmospheric elemental carbon (EC)––an air pollutant that is a powerful climate-forcing agent and threat to human health. Understanding what controls EC deposition to urban trees is therefore important for evaluating the potential role of vegetation in air pollution mitigation strategies. We estimated wet, dry, and throughfall EC deposition for oak trees at 53 sites in Denton, TX. Spatial data and airborne discrete-return LiDAR were used to compute predictors of EC deposition, including urban form characteristics, and meteorologic and topographic factors. Dry and throughfall EC deposition varied 14-fold across this urban ecosystem and exhibited significant variability from spring to fall. Generalized additive modeling and multiple linear regression analyses showed that urban form strongly influenced tree-scale variability in dry EC deposition: traffic count as well as road length and building height within 100–150 m of trees were positively related to leaf-scale dry deposition. Rainfall amount and extreme wind-driven rain from the direction of major pollution sources were significant drivers of throughfall EC. Our findings indicate that complex configurations of roads, buildings, and vegetation produce “urban edge trees” that contribute to heterogeneous EC deposition patterns across urban systems, with implications for greenspace planning.

Microplastics (MPs) are an emerging pollutant and a worldwide issue. A wide variety of MPs and tyre wear particles (TWPs) are entering and spreading in the environment. TWPs can reach waterbodies through runoff, where main contributing particulate matter comes from impervious areas. In this paper, TWPs and other types of MPs that were transported with the runoff of a high populated-impervious urban area were characterised. Briefly, MPs were sampled from sediments in a stormwater detention reservoir (SDR) used for flood control of a catchment area of ∼36 km², of which 73% was impervious. The sampled SDR is located in São Paulo, the most populated city in South America. TWPs were the most common type of MPs in this SDR, accounting for 53% of the total MPs; followed by fragments (30%), fibres (9%), films (4%) and pellets (4%). In particular, MPs in the size range 0.1 mm–0.5 mm were mostly TWPs. Such a profile of MPs in the SDR is unlike what is reported in environmental compartments elsewhere. TWPs were found at levels of 2160 units/(kg sediment·km² of impervious area) and 87.8 units/(kg sediment·km street length); MP and TWP loadings are introduced here for the first time. The annual flux of MPs and TWPs were 7.8 × 10¹¹ and 4.1 × 10¹¹ units/(km²·year), respectively, and TWP emissions varied from 43.3 to 205.5 kg/day. SDRs can be sites to intercept MP pollution in urban areas. This study suggests that future research on MP monitoring in urban areas and design should consider both imperviousness and street length as important factors to normalize TWP contribution to urban pollution.

As a redox-sensitive element, manganese (Mn) plays a critical role in Cd mobilization, especially in paddy soil. In an anoxic environment, the precipitation of Mn(II)-hydroxides specifically favors Cd retention, while draining the paddy fields results in substantial remobilization of Cd. However, how the change in Mn redox states during the periodical transit of anoxic to oxic systems affects Cd mobility remains unclear. In this study, we demonstrate that the radical effect generated during the oxidation of Mn(II)-hydroxides exerts a significant effect on the oxidative dissolution of Cd during the aeration of paddy soils. The extractable Cd concentration decreased rapidly during the reduction phases but increased upon oxidation, while Cd availability produced the opposite effect with soil pe + pH and the extractable Mn concentration. Inhibiting the oxidation of Mn(II)-containing phases by microbes suppressed the production of hydroxyl free radicals (•OH) and Cd mobilization in the drainage phase. Analysis of X-ray absorption spectroscopy and sequential extraction demonstrated that the transformation from the Mn phase of Mn(II) to Mn(III/IV) determines Cd solubility. Altogether, the oxidization of Mn(II)-hydroxides was associated with the generation of significant amounts of •OH. The dissolution of Mn(II)- incorporating phases lead to a net release of Cd into soils during soil aeration.

Electronic waste (e-waste) pollution is of great concern due to the release of hazardous chemicals during the improper e-waste disposal. Many chemicals leached from e-waste were reported to pose estrogenic effects. To date, little is known regarding the occurrence and biological effects of estrogenic chemicals in sediments near an e-waste area. In this study, an effect-directed analysis (EDA) is applied to determine the estrogenic chemicals in sediments of four sites collected from a typical e-waste recycling city in China. Following screening with the ER-CALUX assay, the extract of sample with the most potent effect was subjected in fractionation using reverse phase liquid chromatography. Based on a target analysis for the active fractions, four compounds, including estrone, 17β-estradiol, 17α-ethinylestradiol and bisphenol A, were identified, and these contributed to 17% of the total toxic effects in the sample. A further nontarget analysis screened four candidates, namely diethylstilbestrol (DES), hexestrol (HES), nandrolone and durabolin, and the total contribution was found to be 48% from the active sample. Specifically, DES and HES were only detected in the active sample and were found to be the primary drivers of estrogenic effects. An examination of the identified chemicals in the four sites indicated that these estrogenic chemicals may originate from e-waste recycling, livestock excretion and domestic waste. These findings uncovered the estrogenic pollutants in sediments from an e-waste area. Considering single endpoint in biological assay is not abundant to screen chemicals with different toxic effects, further EDA studies with multiple endpoints are required to better understand the occurrence of representative or unknown chemicals in e-waste-polluted areas.

Surface water is one of the primary sources of irrigation water for produce production; therefore, its contamination by foodborne pathogens, such as Salmonella, may substantially impact public health. In this study, we determined the presence of Salmonella in surface water and characterized the relationship between Salmonella detection and environmental and anthropogenic factors. From April 2019 to February 2020, 120 samples from 30 sites were collected monthly in four watersheds located in two different central Chile agricultural regions (N = 1080). Water samples from rivers, canals, streams, and ponds linked to each watershed were obtained. Surface water (10 L) was filtrated in situ, and samples were analyzed for the presence of Salmonella. Salmonella was detected every month in all watersheds, with a mean detection percentage of 28% (0%–90%) across sampling sites, regardless of the season. Overall, similar detection percentages were observed for both regions: 29.1% for Metropolitan and 27.0% for Maule. Salmonella was most often detected in summer (39.8% of all summer samples tested positive) and least often in winter (14.4% of winter samples). Random forest analysis showed that season, water source, and month, followed by latitude and river, were the most influential factors associated with Salmonella detection. The influences of water pH and temperature (categorized as environmental factors) and factors associated with human activity (categorized as anthropogenic factors) registered at the sampling site were weakly or not associated with Salmonella detection. In conclusion, Salmonella was detected in surface water potentially used for irrigation, and its presence was linked to season and water source factors. Interventions are necessary to prevent contamination of produce, such as water treatment before irrigation.

Benefiting from the pollution controls implemented by the Chinese government, the concentrations of PM₂.₅, SO₂, NO₂ and CO showed a significant decrease in Beijing during 2013–2017. In this study, an observation-based method was employed to estimate the relative contributions of regional transport (MaxRTC) and local emissions (MinLEC) to air pollutant levels during 2013–2017 in Beijing. The results showed that the MaxRTC to SO₂ and PM₂.₅ increased significantly over the five years, while those to CO and NO₂ changed little. Furthermore, the difference in the emissions control efficiency (ΔECE) between Beijing (receptor region) and Shijiazhuang (source region), which refers to the concentration changes corresponding to unit emission changes of a certain air pollutant between the two regions, was introduced to verify the estimated variation in MaxRTC and MinLEC over 2013–2017. The negative value of ΔECE found for PM₂.₅ and SO₂ supports the conclusion of an increasing effect of regional transport. This implies that local emissions control alone is not adequate for mitigating Beijing's air pollution, especially with the demand for continuously improving air quality. Joint prevention and control with regard to air quality on a regional scale is more important and urgent in the next Five-Year Plan.

The gravity of the impending threats posed by microplastics (MPs) pollution in the environment cannot be over-emphasized. Several research studies continue to stress how important it is to curb the proliferation of these small plastic particles with different physical and chemical properties, especially in aquatic environments. While several works on how to monitor, detect and remove MPs from the aquatic environment have been published, there is still a lack of explicit regulatory framework for mitigation of MPs globally. A critical review that summarizes recent advances in MPs research and emphasizes the need for regulatory frameworks devoted to MPs is presented in this paper. These frameworks suggested in this paper may be useful for reducing the proliferation of MPs in the environment. Based on all reviewed studies related to MPs research, we discussed the occurrence of MPs by identifying the major types and sources of MPs in water bodies; examined the recent ways of detecting, monitoring, and measuring MPs routinely to minimize projected risks; and proposed recommendations for consensus regulatory actions that will be effective for MPs mitigation.