环境科学与技术最新文献

The occurrence and accumulation of novel perfluoroalkyl and polyfluoroalkyl substances (PFAS) have emerged as a scientific concern in recent years. While numerous studies have identified elevated concentrations of certain emerging PFAS, the sources and environmental accumulation differences of many homologues remain insufficiently characterized. In this study, we employed suspect and nontarget screening to characterize both legacy and emerging PFAS across environmental matrices, including water, sediment, and soil, surrounding an industrial park with predominant perfluoroalkyl carboxylic acids (PFCAs) contamination. A total of 32 classes comprising 112 compounds were identified, including 80 emerging PFAS detected through the screening approach. In addition to PFCAs, emerging PFAS, including perfluoroalkyl ether carboxylic acids (PFECAs), perfluoroalkyl alcohols (PFAs), and PFA derivatives, were frequently detected in the study area, primarily in water and sediment samples. In contrast, the contamination profile was less complicated in soil samples, where PFCAs were the predominant homologues. The median total concentrations of target PFAS in water, sediment, and soil samples were 427 ng/L, 4.17 ng/g of dw, and 3.92 ng/g of dw, respectively. Predicted risk assessment further indicated that these emerging PFAS with high concentrations pose non-negligible risks to both ecological and human health, underscoring the need for further investigation into their potential impacts.

Dimethyl selenide (DMSe) is the simplest volatile organoselenium compound that can undergo atmospheric oxidation to form secondary aerosols. While the oxidative potential of DMSe-derived aerosols has been shown to be greater compared to that of ambient aerosols from various sources, the role of selenium (Se) in processes governing reactive oxygen species (ROS) production remains unclear. Utilizing dimethyl sulfide (DMS) as a chemical analogue and mechanistic control of DMSe, we detected, quantified, and contrasted ROS produced by DMSe- and DMS-derived aerosols in aqueous solutions and confirmed the changes in Se oxidation state after dissolution. DMSe- and DMS-derived aerosols produced 9.0 ± 2.1 nmol ·OH/μg-aerosol and 0.29 nmol ± 0.11 ·OH/μg-aerosol, respectively. The average 33-fold difference in ·OH produced in these systems implies different dominating mechanisms of formation. DMS-derived aerosols can generate ·OH through organic hydroperoxide decomposition, whereas DMSe-derived aerosols are additionally capable of producing ·OH through Fenton-like reactions by cycling among Se(0), Se(IV), and Se(VI). Selenate (SeO₄^2-), selenite (SeO₃^2-), selenium dioxide (SeO₂), and methane seleninic acid (CH₄O₂Se) were redox-active compounds confirmed within DMSe-derived aerosols. This study highlights the redox cycling of particulate Se and the production of aqueous ·OH, which have important implications for atmospheric aqueous chemistry and Se biogeochemical cycles.

Decarbonizing the iron and steel industry (ISI) reduces air pollutant emissions, yielding substantial public health cobenefits. Existing assessments fail to account for plant-level heterogeneity in production routes and geographic settings─critical determinants of health impacts─hindering the formulation of targeted decarbonization strategies that maximize health gains. Here, by integrating a facility-level emission inventory with inverse atmospheric modeling, we estimate that the Chinese ISI emits 1.56 Pg of CO₂ and 0.85 Tg of PM_2.5 annually, with 147,000 (IQR: 121,000-184,000) annual PM_2.5-attributable premature deaths linked to ISI emissions, and the health burdens varying by 77,500-fold across individual plants. Blast furnace-basic oxygen furnace (BF-BOF) processes impose 3.8 times higher mortality intensity than electric arc furnaces (EAFs) (172 vs 45 deaths per 1000 Gg steel produced), with 80% of mortality concentrated in 21% of plants─predominantly large BF-BOF complexes in densely populated eastern China. Strategically relocating 30 Tg eastern BF-BOF capacity (3.6% of the national total) to scrap-based EAFs in low-carbon southwestern power grids could prevent 12,300 (IQR: 9500-16,100) annual deaths (8.4% reduction), generating USD 24.5 (IQR: 20.0-30.4) billion in combined climate-health benefits. Natural gas-based direct reduced iron-electric arc furnace (DRI-EAF) integration offers a scrap-independent alternative, achieving ∼50% lower mortality than BF-BOF. These findings advance targeted strategies to optimize health outcomes during ISI decarbonization in China.