Air Quality Atmosphere and Health最新文献

This paper aims to assess the impact of individual measures for NOx emission reduction on NO₂ concentrations at very high spatial resolution in an urban district of Madrid City (Spain). A methodology based on a set of Computational Fluid Dynamics simulations for 16 meteorological scenarios combined with the CHIMERE model for background pollution is used to obtain annual NO₂ concentration maps. Two scenarios included in the Spanish National Air Pollution Control Programme are investigated: NOx emission reductions from the installation of more efficient boilers for domestic heating (ECOBOIL) and from the partly substitution of passenger cars with combustion engines by electric cars (EC). This analysis is extended to 9 additional scenarios of more ambitious implementation of electric vehicles in order to determine what the NOx emission reduction required for the annual mean NO₂ concentration EU limit value not being exceeded is. The ECOBOIL scenario has a very weak impact on the NO₂ concentrations. However, the EC scenario implies a more significant reduction of the NO₂ concentrations, but not enough to fully remove NO₂ limit value exceedances in the study area. A small additional (compared with the EC scenario) implementation of electric vehicles seems to fulfil that the spatially averaged NO₂ concentration be lower than the EU limit value, but the area with exceedances is still very large. However, stronger traffic emission reductions (80%) corresponding to the most ambitious scenarios are needed in order to reach that at least 95% of the domain is free of EU limit value exceedances.

Indoor air pollution is a critical health issue. We studied particle emissions, concentration changes and size distribution mechanisms using an indoor space with air quality monitors, incense stick burning, and ventilation. Temporal changes in the concentrations of particles with sizes of 10 nm to 10 µm were monitored. Our findings show that particles affecting particle number concentration (PNC) were mainly in the Aitken mode (50–100 nm) and accumulation mode I (100–200 nm). Particle surface area concentration (PAC) was primarily in the 100–300 nm range, while particle volume concentration (PVC) was in the 100–200 nm and 300–1000 nm ranges. After extinguishing the incense sticks, ventilation was initiated. The ventilation period was split into FAO_1–3 (i.e., the first 3 min, 1–3 min of ventilation system operation) and FAO_4–15 (i.e., the last 12 min, 4–15 min of ventilation system operation). During FAO_1–3, particle concentrations increased by 18.3 to 21.5%. This rise was due to the initial activation of the ventilation system, dispersing settled particles (mostly ≥ 41.2 nm) into the air. The FAO_4–15/FAO_1–3 ratio for 12.3−2489.3 nm particles was always < 1, indicating that as the ventilation continued, it effectively removed particles of < 2.5 μm. After subsequent ventilation of 15-min operation, total PNC, PAC, and PVC were 70.3%, 70.0%, and 67.8% lower than during FAO_1–3 and the particle number mode diameter was 106.0 nm, with geometric standard deviations of 1.50 and 1.51 (left and right), indicating that the ventilation system was successful in removing smoke particles of all sizes simultaneously and evenly and achieved an approximate total removal efficiency of 70%, effectively filtering particles and reducing indoor air pollution.

Graphical abstract

Exposure to air pollutants especially fine particulate matter (PM_2.5) poses serious risks to human health including cytotoxic and genotoxic effects. However, depending on the meteorological conditions and emission sources, chemical composition of PM_2.5 and consequently related adverse health effects may vary in different locations. In this study, cytotoxic and genotoxic effects of water-soluble and organic fraction of ambient air PM_2.5 of Isfahan city, Iran, were evaluated using the MTT and comet assay, respectively. Concentrations of polycyclic aromatic hydrocarbons (PAHs) as important toxic agents of organic fraction of particles were also determined. The results showed that both fraction of PM_2.5 especially organic fraction induce cytotoxic and genotoxic effects at tested concentrations. Analysis of PAHs showed a concentration of 1.5–18.6 ng/m³ of total PAHs and 0.99–11.2 ng/m³ for carcinogenic PAHs, respectively, with an important role on the toxic effect of PM_2.5 organic fraction. Overall, our results showed a considerable cytotoxic effect (0–64%) of organic fraction of fine particles at all times of the year which may be related to the vehicular emission. In addition, the results showed more cytotoxicity of water-soluble fraction of PM_2.5 in dust events. The results of study highlight the need to reduce PM_2.5 pollution especially through controlling of PAH emission sources such as vehicles. However, further research is needed to improve our knowledge about the PM chemical composition and related emission sources to manage air pollution-associated health effects.

The Central-West region of Brazil presents three important and large ecosystems: the Amazon, the Cerrado, and the Pantanal biomes. Different anthropogenic activities (e.g., biomass burning and land use) affect this area, emitting particulate matter (PM) that can be transported to urban sites, adding to the local vehicular sources. Sampling of atmospheric particulate material with a size less than and equal to 10 μm (PM₁₀) was carried out in the medium-sized city of Cuiabá (Brazil), between 2008 and 2014. The maximum concentrations of PM₁₀ were found in the dry season, surpassing the recommended levels by the World Health Organization. A slight seasonal variation was found between the concentrations of organic carbon, elemental carbon, elements, and water-soluble ions (WSI), with higher levels in the dry season, enhanced by biomass burning and dust resuspension. Polycyclic aromatic hydrocarbons, their nitrated and oxygenated derivatives (nitro and oxy-PAHs), and some n-alkanes showed similar behaviors in the dry and rainy seasons, with higher abundance of carcinogenic PAHs compared to the rest of the polyaromatics. Total incremental lifetime cancer risks due to exposure to PAHs were found to exceed the safety level. Based on the application of diagnostic ratios and the positive matrix factorization receptor model, biomass burning, soil and road dust resuspension, vehicular exhaust, and mining activities were pointed out as emission sources. These results allow us to better understand the aerosol sources that contribute to the worsening of air quality in a growing urban area.

In Bangladesh, particularly in Dhaka, gridlock in the transportation network is such a typical occurrence that it is critical to have a thorough understanding of the magnitude of carcinogenic airborne toxins like polycyclic aromatic hydrocarbons (PAHs) along the city’s busy streets. In this study, we investigated the airway deposition of PM_2.5- and PM₁₀-bound 16 USEPA (United States Environmental Protection Agency) designated priority PAHs, their potential sources, and associated health risk. The samples were collected over seven high-traffic congestion areas in Dhaka during the monsoon (June–September 2021) and winter (December–February 2022) seasons and analyzed by gas chromatography–mass spectrometry (GC-MS). The winter season exhibited 2.7 and 2.3 times more PM_2.5- and PM₁₀-bound PAHs than the monsoon. The positive matrix factorization (PMF) identified vehicular emissions as the primary PAHs source, followed by biomass and coal combustion. The transboundary incursion of pollutants was predominant during winter, as almost 91% of the trajectories for air mass came from the neighboring country. An adult inhaled 9.70 μg of PAHs per day during winter, of which 1.22 μg entered the alveolar region of the pulmonary tract via PM_2.5 inhalation. The total B[a]P_eq values ranged from 31.0 to 145.1 ng/m3, substantially exceeding the WHO recommended limit (1 ng/m3). Lifetime lung cancer risk (LLRC) and incremental lifetime cancer risk (ILCR) for different age groups revealed that adults had a higher potential cancer risk due to long-term exposure. Overall, prolonged traffic emission increased the risk of lung cancer due to the deposition of carcinogenic B[a]P in the alveolar region (0.72–3.48 ng/h).

Graphical abstract

The increasing amount of ozone (O₃) pollution in China is attracting extensive scientific attention globally. This study presents direct evidence that high concentrations of volatile sulphur compounds (VSCs) accelerate the photochemical production of O₃. We analysed three high O₃ cases (Cases I, II, and III) in which the O₃ concentrations were high but the compositions of O₃ precursors differed. An analysis of the O₃ precursors and the magnitudes of the associated ROx (ROx = ·OH + ·HO₂ + ·RO₂) reactivities amongst three cases revealed that VSCs may play an important role in O₃ production. Case I showed high loadings of VSCs, mainly dimethyl sulphide (DMS), and the simulated diurnal average concentration of radicals and the net O₃ production rate were higher than those in Cases II and III, reflecting the higher photochemical reactivity and oxidation capacity of Case I. Although O₃ was mainly produced from the oxidation of aromatics in all cases, the oxidation of DMS was an important contributor to O₃ formation in Case I (14%) and Case III (25%). The combined analyses indicated the contribution of DMS to O₃ production in industrial areas and suggested the urgent need to measure related VSCs during field campaigns in another atmospheric environment to verify this phenomenon.

Turkey is under the influence of long-range dust transport from the Sahara Desert in the spring and fall seasons. Studies in the literature reported that high levels of particulate matter (PM₁₀) concentrations were observed in Turkish cities due to dust events, which often occur in April. This study aims to reveal the impact of dust transport events on PM₁₀ concentrations on the western coast of Turkey (26–28 E, 37–41 N) during April 2022. Another purpose of this study is to suggest a proper location for the monitoring station to observe dust transport. Daily measurements of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard Terra and Aqua satellites were examined for dust transport from the Sahara Desert. Three dust events (AOD > 0.5) were detected on the 1^st, 5^th, and 22^nd days of April 2022 according to Terra MODIS data. The impact of these events on PM₁₀ concentrations was analyzed by using measurements of 47 ground air quality monitoring stations in Aydın, Balıkesir, Çanakkale, İzmir, Muğla, and Manisa. The correlations between AOD and PM₁₀ ranged from 0.13 to 0.81. High positive correlations were observed over the southern part of the study area (Muğla and Aydın provinces) which could be considered as a proper location for an air quality monitoring station to observe dust transport to Turkey.

Air pollution is a regional issue, influenced not only by local emission sources but also by regional transport. This study excavated the pollution variation of PM_2.5 and O₃ from 2014 to 2020 through statistical analysis in the megacity-Chengdu. Then, based on backward trajectory calculation and trajectory clustering, the long-term air mass transport pathways were explored, and the Potential Source Contribution Function (PSCF) model and Concentration Weighted Trajectory (CWT) analysis method were combined to further quantitatively identify the potential source areas affecting PM_2.5 and O₃ from an annual perspective. Finally, suggestions and measures for synergistic control of O₃ and PM_2.5 are put forward. The results showed that the CWT simulation results were basically consistent with the PSCF simulations, and there were significant inter-annual differences in the potential contributing source areas of pollutants. PM_2.5 and O₃ concentrations are not only affected by local source emissions, but regional transport (Chongqing, Lanzhou, Xi’an) is also an important source of contribution. In addition, the proportion of PM_2.5 pollution trajectories decreased from 30% in 2015 to 12% in 2020, while the proportion of O₃ pollution trajectories fluctuated. This study provides more detailed information on potential source regions of pollutants in typical megacities, better captures their spatial heterogeneity, and highlights the role of local sources and transboundary transport. More importantly, it also accumulated some experience for regional joint prevention and control air pollution in China’s megacities and other similar situations in the world.

Graphical Abstract

Heavy metals (HMs) in indoor dust are among the most toxic micropollutants and have attracted mainly the attention of researchers in the last three decades concerning the environmental and human health perspectives. Hence, a thorough literature-based bibliometric analysis was inevitably needed to identify the research trend for the prevalence of HMs in indoor environments and their toxicological aspects. Accordingly, exploring publications on the Web of Science Core Collection database to identify the articles published on HM pollution in indoor dust environments revealed several peculiar findings. The review article indicates that the majority of studies conducted in this field are monitoring-based, utilizing “HMs (n = 79) ,” “contaminations (n = 49) ,” “lead (n = 49),” and “health” as primary keywords in the published articles. Among the countries, China emerged as the most active investigator in this area, followed by the USA, Middle East, Turkey, Korea, and India. Additionally, China has established collaborations with ~150 and >90 countries, respectively, solidifying its leading position in publications. Studies on HM pollution in indoor dust have evolved from initial exposure analyses in the 1990s to encompass bioavailability, bioaccessibility, exposure, risk assessment, speciation, and source apportionment assessments. Metal pollution in residential and commercial areas (schools/offices) primarily originates from in-house sources and vehicle emissions, while industrial areas, driven by anthropogenic activities (e-waste recycling/mining), face metal pollution from different sources. The analysis underscores that studies predominantly focus on risk assessment of significant metals, their bioaccessibility/bioavailability, and source apportionments. This study’s exploration of HMs in indoor dust provides explicit content and trends, offering valuable insights for researchers delving into this field. It not only suggests remedial measures but also contributes to the development of forecasting models.

This study aimed to investigate the causes of contrasting ozone (O₃) trends in Spanish O₃ hotspots between 2008 and 2019, as documented in recent studies. The analysis involved data on key O₃ precursors, such as nitrogen oxides (NOx) and volatile organic compounds (VOCs), among other species, along with meteorological parameters associated with O₃. The dataset comprised ground-level and satellite observations, emissions inventory estimates, and meteorological reanalysis.

The results suggest that the increasing O₃ trends observed in the Madrid area were mostly due to major decreases in NOx emissions from the road transport sector in this urban VOC-limited environment, as well as variations in meteorological parameters conducive to O₃ production. Conversely, the decreasing O₃ trends in the Sevilla area likely resulted from a decrease in NOx emissions in a peculiar urban NOx-limited regime caused by substantial VOC contributions from a large upwind petrochemical area. Unchanged O₃ concentrations in other NOx-limited hotspots may be attributed to the stagnation of emissions from sectors other than road transport, coupled with increased emissions from certain sectors, likely due to the economic recovery from the 2008 financial crisis, and the absence of meteorological variations favorable to O₃ production.

In this study, the parameters influencing O₃ varied distinctively across the different hotspots, emphasizing the significance of adopting an independent regional/local approach for O₃ mitigation planning. Overall, our findings provide valuable insights into the causes of contrasting O₃ trends in different regions of Spain, which can be used as a basis for guiding future measures to mitigate O₃ levels.