Air Quality Atmosphere and Health最新文献

This study presents a comprehensive investigation of 12 heavy metals in atmospheric dustfall from Xi’an, a major city in northwestern China, during 2021–2022. The results revealed severe contamination levels, with Cd being the most heavily contaminated element, exceeding the Shaanxi soil background value by 45.1 times, followed by Zn, Pb, and Cu. Notably, acid-extractable fractions of Zn and Ni showed increasing trends compared to levels from a decade ago, whereas Pb exhibited a decreasing trend. Spatiotemporal variations were more pronounced in acid-extractable fractions than in total metal concentrations. Bioavailability assessments identified Zn, Cd, and Mn as the most bioavailable metals, highlighting their enhanced mobility and potential toxicity. Source apportionment resolved three dominant sources in urban areas-natural sources (35.8%), industrial/traffic emissions (26.5%), and coal combustion (25.6%)-while industrial and coal-related sources predominated (31.1%) in surrounding counties. Health risk assessment underscored Cr as a major concern, presenting notable carcinogenic and non-carcinogenic risks. This work provides novel insights into the bioavailability and evolving trends of metal fractions in dustfall, offering a scientific basis for targeted pollution control in arid and semi-arid urban environments.

The debate over whether mobile or stationary sources are the primary contributors to urban air pollution persists. To accurately assess the specific impact of a coal-fired power plant in Hefei on local air quality, this study was conducted on Hefei Science Island from January to February 2025. Utilising two-dimensional multi-axis differential absorption spectroscopy (2D-MAX-DOAS), the horizontal distribution of NO₂ was observed. The technique was used to measure the differential slant column densities (dSCDs) of NO₂ and O₄ in eight azimuthal directions within ultraviolet spectral window, thereby establishing a spatial distribution data foundation for source apportionment. Based on observational data, the vertical distribution of NO₂ within the atmosphere and the height of the mixing layer were inverted. Considering the exponential distribution characteristic of NO₂ in the inversion results, a correction factor was proposed to adjust the volume mixing ratio of NO₂. Multiplying this corrected value by the mixing layer height yielded the vertical column density of NO₂. Comparisons were made between the mixing layer height and lidar observations, as well as between the vertical column density of NO₂ and TROPOMI satellite data. The results demonstrated high consistency, thereby further validating the reliability of the horizontal NO₂ concentration data. The study indicates that NO₂ concentrations near a power plant in Hefei remain around 20 µg/m³, suggesting a limited contribution to local NO₂ pollution and not constituting a primary source.

Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) were investigated in the atmosphere of Admiralty Bay, Antarctic Peninsula. Sampling was conducted using semi-permeable membrane devices (SPMDs) deployed during the austral summers of 2023 and 2024, and the spring of 2023. Contaminant profiles, temporal variations, and potential sources were evaluated to gain a deeper understanding of pollutant dynamics in this remote region. The presence of atmospheric contaminants was influenced by long-range atmospheric transport (LRAT), local emissions, volatilization from snow, soil, and water, short-term meteorological variations, and degradation processes. Hexachlorobenzene was the most abundant and frequently detected compound (mean: 2.88 ± 0.62 ng g⁻¹ triolein), primarily associated with LRAT. In contrast, other organochlorine pesticides (mean: 0.18 ± 0.22 and 0.27 ± 0.45 ng g⁻¹ triolein for aldrin and dieldrin, respectively) and polybrominated diphenyl ethers (mean: 0.02 ± 0.03 ng g⁻¹ triolein) are likely to have originated from secondary sources. The detection of low-chlorinated polychlorinated biphenyls (mean: 0.42 ± 0.41 ng g⁻¹ triolein) at higher altitudes during spring and summer suggests LRAT as a significant transport mechanism. PAHs (mean: 2.39 ± 2.73 ng g⁻¹ triolein) appeared to be more strongly influenced by local sources, with enhanced volatilization and increased human activity during the summer complicating source attribution. Overall, POPs distribution was predominantly shaped by LRAT, while local processes drove PAHs concentrations. The use of SPMDs proved to be an effective passive sampling approach for assessing organic pollutants in remote polar environments. These findings underscore the need for long-term monitoring and international efforts to control emissions. This study supports the goals of the Madrid Protocol and highlights the vulnerability of polar regions to global contamination.

Unlike symmetric canyons, step-down configurations enhance windward pollutant accumulation, aggravating local air pollution.To address this issue, this study used the computational fluid dynamics (CFD) model, validated through the wind tunnel experiments, to systematically assess the performance of 120^° deflection-angle wind catchers (The direction of the incoming wind is at a 30° angle to the wind-catcher structure) with three different inclination lengths in regulating flow patterns and enhancing vehicle exhaust dispersion within a step-down canyon equipped with green belts or solid walls, under a perpendicular wind condition. Results demonstrate that: (1) the standalone use of solid walls increases the overall pollutant concentration in the canyon by 5.4%, it significantly reduce pollutant levels in health-sensitive areas (e.g., at pedestrian breathing height (PBH) in windward zone, average and maximum pollutant concentrations decreased by 35.6% and 42.9% respectively), while green belts alone are ineffective; (2) wind catchers can significantly intensify the counter-clockwise primary vortex, while eliminating near-ground horizontal flows, leading to substantial reductions in the pollutant concentrations, along with achieving uniform windward-side pollutant distribution along the street axis; and (3) the coupled use of a wind catcher with solid walls provides additional reduction of pollutant concentrations in health-sensitive areas (e.g., under three different wind catcher’s inclination lengths, average and maximum concentrations decreased by 3.5–11.9% and 16.0-22.6% respectively at the windward wall, and by 15.4–24.1% and 15.1–22.0% at PBH in the windward pedestrian area), whereas the wind catcher-green belts system yields no additional benefits. The study highlights the effectiveness of wind catchers, especially when integrated with solid walls, in improving step-down canyon air quality. 

Low air quality is a major contributor to cardiorespiratory disease burden and mortality, particularly in countries with vast territorial, socioeconomic, and demographic diversity such as Brazil. Addressing these health risks requires understanding their spatiotemporal patterns, which has not been fully explored in Brazil. This study integrates meteorological and air pollution data from MERRA-2, emissions, land-use, and human development indices to investigate the spatial variability of hospitalization rates and their associations with environmental drivers using Relative Risk estimates and spatial correlation techniques. Our analysis reveals significant spatial heterogeneity in hospitalization rates and trends across Brazil (2008–2019). The Southern region exhibits the highest median rates and localized increases, while hotspots of high rates and upward trends emerge along the Southeast-Northeast corridor. Positive trends in PM_2.5 and O₃ align with increased hospitalizations, while CO and SO₂ trends vary regionally. SO₂ and humidity are identified as the strongest relative risk factors. The Southeast region concentrates the most significant health threats, with hotspots also detected in the Federal District and along the Northeast coastline, linked to transportation and industrial emissions. Regions with high human development levels face compounded risks and limited adaptive capacity, emphasizing the need for targeted mitigation strategies. This study offers high-resolution insights into the interplay of air pollution, meteorology, and health, providing a critical resource for policymakers to design adaptive public health interventions in resource-constrained settings.

The current study aims to explore the chemical composition and influence of several sources of coarse aerosol fractions (PM₁₀) for the industrial regions of Vapi and Ankleshwar from December 2019 to February 2020. PM₁₀ refers to particulate matter with aerodynamic diameter of 10 micrometres or less. For Ankleshwar and Vapi, the yearly average PM₁₀ concentration is between 100.98 and 225.47 µg/m³ and 115.88 to 226.5 µg/m³. The results of the chemical study for Ankleshwar indicated contributions from EC & OC in the range of 44–48%, WSIs in the range of 21–26%, and elements in the range of 29–31% of PM₁₀ mass. In Vapi, the total carbon constituted 45 to 48% of PM₁₀ mass, WSIs constituted 22 to 26% and elements contributed 26 to 29% of PM₁₀ mass. The significant sources for both Ankleshwar and Vapi are then assessed using PMF. For Ankleshwar, source apportionment using PMF showed the contribution from various sources as 27.73% by crustal or soil dust, 22.94% by burning fossil fuels, 17.94% by vehicular emissions, 13.97% by secondary aerosols, 9.10% by biomass burning, and 8.32% by industrial emissions. Using the PMF receptor model for Vapi, the following sources of effect were identified: combustion (25.75%), crustal or soil dust (22.13%), vehicular emissions (16.95%), biomass burning (14.53%), industrial emissions (11.49%), and secondary aerosols (9.16%). According to the backward trajectory model analysis conducted with HYSPLIT, during the study period, the majority of air mass parcels are observed approaching the Ankleshwar site from the northern regions of Gujarat and Madhya Pradesh, whereas, for Vapi, the impending air parcel is conveyed from the northern region of Maharashtra. The results of this analysis will be used to develop methods for mitigating pollution and enhancing the ambient air quality in the study area. Higher PM₁₀ or PM_2.5 concentrations are reported to be triggered by the combustion of fossil fuels, crustal or oil dust, and vehicle emissions. When developing air pollution control strategies, these sources should be given higher emphasis.

This study analyzed the characteristics and sources of aerosols in the Mt. Everest region from May to October 2022 based on instrumental observations and Potential Source Contribution Function (PSCF) analysis. Aerosols were classified into background-, coarse-, and fine-mode dominated types according to the PM₂.₅/PM₁₀ mass-ratio. Both coarse- and fine-mode aerosol increases were linked to low temperature and humidity, strong winds, and high single-scattering albedo (SSA), with black carbon (BC) showing the strongest positive correlation, indicating enhanced transport and reduced wet removal. The scattering and absorption Ångström exponents (SAE and AAE) effectively describe particle size and absorption feature, showing clear spectral signatures of dust-dominated scattering and carbonaceous absorption. The absorption and scattering coefficients of different aerosol modes decreased with increasing wavelength, whereas SSA increased with increasing wavelength, which was consistent with the optical behavior of dust in this region. PSCF analysis showed distinct source regions for each aerosol mode: coarse-mode aerosols mainly originated from northeastern and central India, whereas fine-mode aerosols were primarily transported from the Bay of Bengal. Although the Mt. Everest atmosphere is generally clean, it is strongly influenced by transboundary aerosols from South Asia. These results provide new insights into the physical, optical, and meteorological mechanisms governing regional and long-range pollution over high-altitude environments of the Tibetan Plateau.

The Salton Sea region faces significant air quality challenges, with particulate matter ≤10 μm (aerodynamic diameter, i.e., PM₁₀) concentrations exceeding regulatory standards for 24-hour mean values established by the US Environmental Protection Agency (150 µg m⁻³) and the State of California (50 µg m⁻³). The lake’s receding shoreline has exposed areas of lakebed, creating potential sources for wind-blown dust. In response, the Salton Sea Management Plan aims to construct habitats and implement dust suppression strategies for areas expected to be exposed by 2028. A key component of this effort is to use roughness elements superposed on the exposed lakebed to mitigate dust emissions by reducing wind shear and inhibiting saltation. This study uses computational fluid dynamics to analyze array effectiveness across multiple wind directions for a defined roughness element size, density (number per hectare), and distribution (nominally a staggered array). In contrast to other studies of roughness arrays, we utilize roughness element locations and orientations from an existing array at the Salton Sea and perform a surface integral over the exposed surface to predict emissions. A relation between mass flux of PM₁₀ and shear stress was used in the post-processing of simulated wind shear on the surface, to estimate the total emissions of PM₁₀ before and after the installation of the roughness array. Our findings demonstrate a significant reduction in both shear stress on the intervening surface and dust emissions compared to the same area without the roughness, a result that is further supported by measurements. This research underscores the potential of engineered roughness arrays to improve air quality in regions affected by dust emissions.

This study investigates how environmental policy interventions influence the Environmental Kuznets Curve (EKC) in India, an emerging economy, using annual data from 1980 to 2023 and the Dynamic Autoregressive Distributed Lag (DARDL) model. It focuses on major initiatives including the Perform, Achieve and Trade (PAT) scheme, the FAME programs, and the National Hydrogen Energy Mission. By incorporating interaction terms between GDP and policy variables, the analysis measures how these policies moderate the impact of economic growth on CO₂ emissions. The results confirm an inverted U-shaped EKC for India, with economic growth initially increasing emissions but declining after a threshold income. Importantly, the policies significantly flatten the curve: a 1% increase in electric vehicle adoption and hydrogen use reduces CO₂ emissions by approximately 1.5% in the short term and 0.16% in the long term. Policy interventions also bring forward the EKC turning point from around USD 28,000 per capita to roughly USD 1,800 per capita, demonstrating that strategic environmental policies can accelerate emission reductions without hindering growth. These findings emphasize that India’s environmental improvements are driven by proactive policy measures rather than market forces alone, offering valuable guidance for policymakers in other emerging economies seeking sustainable growth.

Temperature variability, particularly diurnal temperature range (DTR), has been linked to mortality, yet evidence from low- and middle-income settings remains limited. We analyzed 188,039 deaths in Ningbo, China (2014–2018) using a time-series design with a distributed lag non-linear model. A J-shaped DTR–mortality curve was observed, with a city-specific minimum-mortality DTR (MMDTR) of 15.3 °C. Both low and high DTR increased mortality risk. Cause-specific effects were largest for endocrine, nutritional, and metabolic diseases (higher excess risk 18.9%), followed by circulatory (5.7%) and respiratory (4.2%) deaths. Females and older adults were more vulnerable. Children showed elevated risks that were not statistically significant and were imprecisely estimated (wide confidence intervals). Overall, 22.7% (~42,711) of deaths were attributable to DTR, largely from the common low-to-moderate DTR range (20.4%;~38,369), despite steeper relative risks at the upper tail. Both low- and high-DTR conditions merit attention; preparedness for high-DTR episodes may need to increase with climate change, while routine protection during frequent low-DTR days could yield substantial benefits, especially for females and older adults, and children, who showed high point estimates despite wide confidence intervals.