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1.
Toxics ; 12(3)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38535935

RESUMO

Black carbon (BC) aerosols are important for absorbing aerosols, affecting global climate change and regional air quality, and potentially harming human health. From March to May 2023, we investigated black carbon aerosol levels and air pollution in Beijing. Employing methods such as linear regression, Potential Source Contribution Function (PSCF) and Concentration-Weighted Trajectory (CWT), we analyzed the characteristics and sources of black carbon aerosols in the region. Results indicate that the light absorption coefficients of BC and BrC decrease with increasing wavelength, with BrC accounting for less than 40% at 370 nm. Daily variations in BC and PM2.5 concentrations exhibit similar trends, peaking in March, and BC displays a distinct bimodal hourly concentration structure during this period. Aethalometer model results suggest that liquid fuel combustion contributes significantly to black carbon (1.08 ± 0.71 µg·m-3), surpassing the contribution from solid fuel combustion (0.31 ± 0.2 µg·m-3). Furthermore, the significant positive correlation between BC and CO suggests that BC emissions in Beijing predominantly result from liquid fuel combustion. Potential source area analysis indicates that air masses of spring in Beijing mainly originate from the northwest (40.93%), while potential source areas for BC are predominantly distributed in the Beijing-Tianjin-Hebei region, as well as parts of the Shandong, Shanxi and Henan provinces. Moreover, this study reveals that dust processes during spring in Beijing have a limited impact on black carbon concentrations. This study's findings support controlling pollution in Beijing and improving regional air quality.

2.
Artigo em Inglês | MEDLINE | ID: mdl-36293595

RESUMO

In this study, a large construction waste dump in Beijing, China, was used as the study area. Nineteen effective atmospheric dust samples were collected. The mass fractions of 14 metal elements (Ca, Fe, Al, Mg, Mn, Zn, Cr, Cu, V, Pb, Ni, As, Co, and Cd) were determined for the samples using ICP-MS. The pollutants and the potential ecological risk levels of 10 different heavy metals were evaluated using the enrichment factor, geo-accumulation index, and a potential ecological risk assessment method. The results showed that the Ca, Fe, Al, and Mg contents in the dust fall were considerably high and accounted for 98.81% of the total mass of the analysed metals. Cd and Zn were the main metal contaminants in the dust fall in the vicinity of the construction waste dump, followed by Cu and Mn. The Cd, Zn, Cu, and Mn contents in the construction waste had a significant impact on atmospheric pollution within 250 m of the dump. Moreover, Cd had the largest contribution to the comprehensive ecological risk posed by the heavy metals in the dust fall and was determined to be the primary ecological risk factor in the atmospheric environment in the vicinity of the construction waste dump.


Assuntos
Poluentes Ambientais , Metais Pesados , Poeira/análise , Pequim , Monitoramento Ambiental/métodos , Cádmio/análise , Chumbo/análise , Metais Pesados/análise , Medição de Risco , Instalações de Eliminação de Resíduos , China , Poluentes Ambientais/análise
3.
Huan Jing Ke Xue ; 42(1): 38-44, 2021 Jan 08.
Artigo em Zh | MEDLINE | ID: mdl-33372455

RESUMO

To reveal the pollution characteristics and the health risks of the trace heavy metals in the atmospheric particles in Baoding, Hebei province, PM2.5 samples were collected using a middle volume sampler, and the mass concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in the samples were determined by microwave digestion-inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the PM2.5 concentration in Baoding ranged from 16.84-476.2 µg·m-3. During sampling, 65 samples were above the second-level standard of the Ambient Air Quality Standards (GB 3095-2012) by 54.2%. The most heavy metal elements showed higher levels in nighttime than during the daytime, except for except for Ni, Mn, and Co. Obvious seasonal variation was found with the trend of winter > autumn > spring > summer. The enrichment factors for Cu, Zn, Pb, and Cd were more than 1.5, indicating that those metals mainly came from anthropogenic emissions, such as traffic sources. Health risk assessment results indicated that the non-carcinogenic risk of heavy metals in PM2.5 in Baoding was small, and the carcinogenic risk resulting form As, Cr, Cd, and Co was greater for adults than for children.


Assuntos
Poluição do Ar , Metais Pesados , Adulto , Poluição do Ar/análise , Criança , China , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Material Particulado/análise , Medição de Risco
4.
Huan Jing Ke Xue ; 42(4): 1626-1635, 2021 Apr 08.
Artigo em Zh | MEDLINE | ID: mdl-33742797

RESUMO

In order to reveal the chemical composition characteristics and pollution sources of fine particulate matter (PM2.5) in autumn and winter in Yuncheng, PM2.5 samples were continuously collected using a four-channel small-flow particulate sampler from October 15, 2018 to March 15, 2019. The study prediminantly analyzed the chemical components of water-soluble ions, elemental carbon, organic carbon, and metal elements. Additionally, the chemical mass reconstruction method of particulate matter and the positive matrix factorization model (PMF) were combined for an in-depth discussion. During the sample period, the PM2.5 mass concentrations range was 29.37-370.11 µg·m-3, and 101 days during the sampling period exhibited concentrations that were higher than the secondary standard in China's Ambient Air Quality Standards (GB 3095-2012), with an exceeding rate of 70.63%. These results indicate that the air pollution in Yuncheng in autumn and winter is serious. According to the air quality index (AQI), the collected samples are classified as clean, light-moderate pollution, and heavy-severe pollution. Water-soluble ions, OC, EC and metal elements account for 40%, 19%, 5%, and 7% on clean days, 46%, 18%, 4%, and 5% on days with light-moderate pollution, and 46%, 21%, 4%, and 4% on days with heavy-severe pollution, respectively. Secondary ions NO3-, SO42-, and NH4+ are the primary components of water-soluble ions, accounting for 81% (clean days), 87% (light-moderate pollution), and 87% (heavy-severe pollution) of the total ion concentration, respectively. The OC/EC ratios during the sampling period were 3.78 (clean days), 4.02 (light-moderate pollution), and 5.37 (heavy-severe pollution). With the intensification of pollution, the pollution of secondary organic aerosols in the atmosphere becomes increasingly serious. In addition, as the air pollution increased, the concentration of Fe and Cr elements gradually decreased, while the concentration of other metal elements showed an overall upward trend. The results of the chemical mass reconstruction demonstrate that among the different pollution levels of atmospheric PM2.5 in Yuncheng, the mass percentages of secondary inorganic salt, sea salt, heavy metals, mineral dust, construction dust, organic matter, and elemental carbon were 36%, 2%, 2%, 8%, 1%, 33%, and 5% (clean days), 41%, 1%, 1%, 5%, 0.01%, 31%, and 5% (light-moderate pollution), and 41%, 1%, 1%, 4%, 0.004%, 34%, and 4% (heavy-severe pollution). The proportion of secondary inorganic ions increased and mineral dust decreased with the deterioration of air quality. The PMF analysis results suggest that secondary related sources, coal combustion sources, vehicle exhaust sources, biomass burning, and secondary organic matter are the predominant sources of PM2.5 during serious air pollution in Yuncheng.

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