Aerosol Science and Engineering最新文献

Due to concern with the health and environmental impacts of allergic pine pollen on an urban community in Las Vegas, Nevada, a computation fluid dynamics (CFD) modeling framework was established for investigating the dispersion and deposition of pollen emitted from inventoried pine trees. The framework employs a Eulerian–Lagrangian approach with mesh grids of < 10 m to simulate wind flows and track pollen particle movements around real-world building blocks. The initial assessment focused on a spring pollen episode and a low period following the episode. Model results highlighted that building structures constrained pollen transportation by reducing wind speeds, especially during the low period, and altered pollen distributions, creating hot spots and cold spots at the windward and leeward sides of buildings, respectively, on the pollen trajectories. The majority of pollen particles appear to deposit onto the ground or buildings 1–3 km downwind from the sources through gravitational settling. Multiple model validations are presented, while limitations and potential applications are discussed.

Occurrence, distribution, ecological risk and health risk of chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), arsenic (As) and cadmium (Cd) in PM2.5 of indoor dusts from Xi’an were determined. All the target elements were detected in the samples, and the maximum Cr, Mn, Ni, Cu, Zn, Pb, As and Cd contents in PM2.5 of dusts were 458, 1005, 115, 604, 2845, 1778, 122.6, and 21.1 mg/kg, respectively. Human activities, industrial produce and traffic could be the main reason for the detection of heavy metals in PM2.5. Cd exhibited significantly high potential ecological risk, which suggested that more attention should be paid to the ecological and environmental effects of Cd pollution. Health risk analysis shows that ingestion of dust particles is the route of exposure for metals in dust, followed by dermal adsorption and inhalation. For children, hazard indexes (HIs) for metals As and Pb were lager than 1, indicating the adverse non-carcinogenic risk for children. Overall, this study provides fundamental information regarding the occurrence, distribution, ecological risk and health risk of heavy metals, which could be helpful for further investigating the health risks of heavy metals in atmospheric environments.

Ambient air quality measurements were carried out between November 2018 and October 2019 along high- and low-traffic density routes in Lagos and Ile-Ife in southwestern Nigeria in order to evaluate the air pollution loads at each airshed. Four sampling points were established during dry and wet season periods over an averaging period of 24 h, while meteorology and ambient measurements were carried out simultaneously at each of the sampling points. Particulate matter (PM_2.5) concentrations were measured using air metric particulate matter sampler, while ambient gaseous concentrations of carbon monoxide (CO), nitrogen oxides (NO₂)_, sulfur dioxide (SO₂), ozone, and volatile organic compounds (VOC) were measured using CO data logger, Ogawa sampler, and 3 M air monitor badge. The samples collected using the Ogawa sampler and 3 M air monitor badge were analyzed using ion chromatography and gas chromatography. The measured ambient mean PM_2.5 concentration in Lagos was 152.6 ± 61.7 µg/m³, while that of Ile-Ife was 93.1 ± 2.2 µg/m³. The measured concentrations of NO₂ in Lagos ranged from 22.0 to 65.0 µg/m³ and that for Ile-Ife ranged from 10.0 to 55.0 µg/m³. SO₂ concentration ranged from 20.6 to 58.1 µg/m³ in Lagos and 16.4 to 60.7 µg/m³ in Ile-Ife. CO concentrations in Ile-Ife sampling points ranged from 1030.7 to 3000.4 µg/m³, while that of Lagos sampling points ranged from 1030.7 to 3664.6 µg/m³. Higher average level (40.0 ± 8.5 µg/m³) of VOC was recorded in Lagos than Ile-Ife with an average value of 17.3 ± 5.5 µg/m³. All ambient pollutant values were below Federal Ministry of Environment and World Health Organization limits except PM_2.5 and SO₂. Therefore, toxicity potential data are useful for better air quality management in compliance with local statutory limit.

Air pollution is one of the major concerns of India as it is the second leading risk factor, with pollutants being released faster than they can be absorbed and dispersed, contributing to one-quarter of the global disease burden. Both urban and semi-urban regions face pollution due to increased private transportation, resource exploration, industrial development, and improved living standards but studies have only focused on outdoor air pollution in urban areas, while the entire country of India is not merely urban, it also affects the nonurban areas just as much as the urban location. The current study was an attempt to measure ambient air quality in terms of PM_2.5 and associated heavy metals (Al, Ca, Co, Cu, Cr, Fe, Mn, Pb, Ni, and K) collected from two different locations (semi-urban and urban) near very busy crossing on National Highway with the help of fine particulate dust sampler (APM-550) during the study period July and August 2020. From the outcomes, it was determined that the influence of PM_2.5 concentrations was greater at the semi-urban than at urban sites. Concentrations of PM_2.5 have been compared with World Health Organization, National Ambient Air Quality Standards, and United States Environmental Protection Agency (USEPA) standards and were found to be exceeded the prescribed limit. The correlation was done between the fine particulate concentrations and meteorological parameters which shows an inverse relation in both sites. Among analyzed heavy metals, Ca (11.65 µg/m³) showed the highest concentration due to various construction materials, such as cement, brick lime, and concrete as well as road dust, accompanied by Al (1.39 µg/m³) and Fe (0.97 µg/m³). The enrichment factor (EF) values concluded that Al, K, Fe, and Mn is less enriched (EF < 10), while Co and Pb had been classified as very highly enriched (EF > 100). Risk characterization for non-carcinogenic and carcinogenic effects was evaluated through ingestion, dermal contact, and inhalation pathway posed by heavy metals in fine particulate matter, the results showed that Co showed non-carcinogenic risk at both urban and semi-urban locations from different pathways (USEPA in Part A, Human health evaluation manual; Part E, Supplemental Guidance for dermal risk assessment; Part F, Supplemental Guidance for inhalation risk assessment 1. Part E Access available online—risk assessment guidance for superfund (RAGS): Part E|US EPA, Part F, Risk assessment guidance for superfund (RAGS): Part F|US EPA, 2011), whereas Ni from the different sites showed an insignificant health risk for both children and adults (HQ ≤ 1) while, Cr, Pb, and Co cause the highest carcinogenic as exceeding the benchmark limit of 1 × 10^–6 as prescribed by USEPA (2011), but Ni was found to be safe at both locations.

The degradation of air quality remains one of the most pressing environmental issues as exposure to air pollutants is extensively associated with various health problems including respiratory and cardiovascular diseases. The present study aims to (1) reveal the annual and periodic variations of PM_2.5, total suspended particles, and selected gaseous pollutants (SO₂, CO, NO₂, HF) in Astana, Kazakhstan by analyzing 2-year air pollution monitoring data (October 2018–September 2020) divided into two study cycles (October 2018–September 2019 and October 2019–September 2020, respectively); and to (2) identify potential air pollution sources in the region using conditional bivariate probability function (CBPF). Annual concentrations of PM_2.5 and other gaseous pollutants were generally high, exceeding World Health Organization air quality guidelines and nationally adopted air quality standards, with heating periods (October–April) characterized, on average, by higher ambient concentrations than non-heating periods. Notably, the concentrations of observed pollutants were higher during the 2018–2019 study cycle than in 2019–2020. Obtained results are useful for subsequent estimation of the burden of respiratory and cardiovascular diseases in the region. The CBPF analysis of PM_2.5 data suggested a general contribution of the coal-fired power plants as well as residential heating activities to the air pollution in the city, while a joint contribution of vehicular emissions and power plant activity was identified as the pollution source of SO₂. Control measures for PM_2.5 and SO₂ emissions specifically arising from the coal-fired power plants need to be urgently implemented.

COVID-19 had such a devastating effect on humanity that several governments worldwide were forced to establish regional and national level Lockdowns in an attempt to reduce the severity of the infection. The nationwide lockdown had been implemented on 24 March 2020 in India with the inevitable restrictions. Along with the effect on the population of more than 1.3 billion people, unprecedented variations in air pollution levels across the country have been witnessed. This Geographic Information System (GIS) approach aims to provide a detailed analysis of spatiotemporal variations in pollution levels prior to, during, and after the Lockdown at multiple locations in Delhi using pollution data from ground monitoring stations under the supervision of the Central Pollution Control Board (CPCB). The monthly contributions of toxic pollutants were determined using several statistical methods, among which the exponential averaging method demonstrated the most favorable outcomes. The interpolation techniques were used to estimate the spatial pollution extent. The study reveals that the residential areas and the commercial complexes had a significant reduction in the pollutant levels in the presence of the lockdown and again a sudden increase in pollution after the relaxation of the curbs. Furthermore, a site suitability analysis was utilized to tackle the growing pollutants level by choosing specific points wherein air quality purifiers can be installed.