ENVIRONMENTAL POLLUTION
·
2017
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IF 5.099
Mengjie Guo,Yan Lyu,Tingting Xu,Bo Yao,Weihua Song,Mei Li,Xin Yang,Tiantao Cheng,Xiang Li
This study presents the particle size distribution and respiratory deposition estimates of airborne perfluoroalkyl acids (PFAAs) during the haze period. Size-segregated haze aerosols were collected from an urban location in Shanghai using an eight-stage air sampler. The samples were analyzed for eight PFAAs using ultra-high-performance liquid chromatography tandem triple quadrupole mass spectrometry. The quantification results showed that the concentrations of particle-bound Σ 8PFAAs ranged from 0.26 to 1.90 ng m −3 (mean: 1.44 ng m −3 ). All of the measured PFAAs particle size distributions had a bimodal mode that peaked respectively in accumulation size range (0.4 < Dp < 2.1 μm) and coarse size ranges ( Dp > 2.1 μm), but the width of each distribution somewhat varied by compound. The emission source, molecular weight , and volatility of the PFAAs were important factors influencing the size distribution of particle-bound PFAAs. Of these compounds, PFUnDA presented a strong accumulation in the fine size range (average 75% associated with particles <2.1 μm), followed by PFOA (69%) and PFDA (64%). The human risk assessment of PFOS via inhalation was addressed and followed the same pattern as the size distribution, with a 2-fold higher risk for the fine particle fraction compared to the coarse particle fraction at urban sites. Approximately 30.3–82.0% of PFAA deposition (∑PFAA: 72.5%) in the alveolar region was associated with particles <2.1 μm, although the contribution of fine particles to the total PFAAs concentration in urban air was only 28–57% (∑8PFAAs: 48%). These results suggested that fine particles are significant contributors to the deposition of PFAAs in the alveolar region of the lung.
研究领域:
环境科学
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公共卫生
✓ 已验证
DOI
高影响因子
Science China-Chemistry
·
2024
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IF 10.4
Yang Ning,Gong Chu,Zhang Dongmei,Gao Xufeng,Han Lifeng,Fu Pingqing,Zhang Xinxing
Humic-like substances (HULIS), a class of macromolecular photosensitizers, are major components of light-absorbing aerosols in the atmosphere. Due to the amphiphilic nature of HULIS, they tend to appear at the air-water interface of atmospheric water. However, there have been limited studies on the photosensitized chemistry of HULIS at the air-water interface owing to the lack of methods with high interface selectivity. Here, a unique field-induced droplet ionization mass spectrometry (FIDI-MS) technique was used to investigate the photosensitized chemistry of several samples at the air-water interface. These samples include commercially available humic acid and the PM 2.5 sample collected during Beijing’s severe winter haze in December 2016. Ultrahigh-resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) was also applied to analyze the atomic compositions, the degree of unsaturation and the aromaticity of these samples. Both Type I and Type II photosensitized oxidation pathways were observed, which were postulated to be dictated by the packing density of the molecules at the air-water interface. These findings reveal that the photosensitization of HULIS at the air-water interface contributes greatly to the formation of atmospheric aerosols, further advancing our understanding of the important roles played by photosensitized chemistry in the atmosphere.
研究领域:
大气科学
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环境化学
✓ 已验证
产品关联
DOI
高影响因子
npj Climate and Atmospheric Science
·
2025
·Vol. 8
·期 1
·1-12
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IF 8.4
Liu Yangyang,Li Xiao,Ge Qiuyue,Fang Xiaozhong,Wang Tao,You Wenbo,Wang Wei,Xie Lifang,Li Kejian,Gong Kedong,Yang Le,Wang Runbo,Wang Jilun,Wang Licheng,Ma Minglu,Huang Tingting,Fu Hongbo,Chen Jianmin,Dong Xinyi,Zhang Liwu
Carbonate radical anion ( \({{\rm{CO}}}_{{3}^{.-}}\) ) is generally considered as a marginal intermediate that rarely regulates atmospheric-relevant reactions of significance. Unexpectedly, in this work, employing a suit of the in-field measurements, lab-based validations, improved kinetic numerical calculations, and chemical transport modeling, we demonstrate that \({{\rm{CO}}}_{{3}^{.-}}\) gives a significantly overlooked contribution (~54.4%) to overall secondary sulfate formation during dust storm-relevant episodes and ~236.3% increase of SO 2 uptake over mineral dust pathway during haze-relevant periods. GEOS-Chem modeling results further emphasize the important position of this radical ion in dust-driven SO 2 oxidation chemistry. Our finding leaves this active intermediate no longer a marginal oxidant currently prevailing in the framework of the atmospheric science community. More importantly, after considering this rapid dust-driven sulfate formation channel mediated by carbonate radicals during pollution episodes, this study provides a clear indication that high priority should be given to reducing alkaline soil dust emissions to achieve benefits for air quality.
研究领域:
大气科学
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环境化学
✓ 已验证
产品关联
DOI
高影响因子
ATMOSPHERIC ENVIRONMENT
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2021
·
IF 4.798
Lihui Han,Xinhang Liu,Yuanyuan Chen,Xin Xiang,Shuiyuan Cheng,Haiyan Wang
A significant technique of combining simulation experiments with a long-term real-time field measurement was first deployed to explore impacts of various environmental factors on formations of sulfate aerosol on the surface of mineral aerosols as MgO in the different reaction systems, and synergistic impacts of these environmental factors on the formation of sulfate aerosols in the different seasonal systems, especially in haze days. Meanwhile, a new correction technique was developed to estimate the effective reaction area and initial uptake coefficient of SO 2 on the MgO aerosol surfaces. The significant results showed that the reactions of SO 2 on the MgO aerosol surfaces in the system of SO 2 -MgO-dark could produce a small amount of sulfate and a large amount of sulfite and bisulfite, while in the systems of SO 2 -MgO- hν and SO 2 -MgO-O 3 produce a large amount of sulfate and a small amount of sulfite and bisulfite. The impacts of temperature T and relative humidity RH on the sulfate formation on MgO aerosol surfaces showed a single-peak mode under the UV light condition, respectively. The sensitivities of these environmental factors to the sulfate aerosol formation were found to follow the order of RH > UV >T > O 3 > SO 2 . The revised initial uptake coefficient γ 0 . REV of SO 2 on the MgO aerosols was always between γ 0.BET and γ 0 . GEO , and much closer to actual value. The heterogeneous reaction mechanisms of SO 2 on the MgO aerosol surfaces in the different reaction systems were obviously different. In the presence of water, light irradiation and O 3 exerted crucially significant roles in promoting sulfate heterogeneous formation. The various environmental factors in the different seasonal systems, especially in haze days, showed different synergistic effects on sulfate aerosol formations. The sulfate aerosol formations in haze days were mostly impacted by RH, T, O 3 , and SO 2 in spring, RH in summer, RH, T, and SO 2 in autumn, and RH and SO 2 in winter. The study will provide significant scientific bases for understanding and controlling haze pollution formation.
研究领域:
大气化学
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环境科学
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气溶胶科学
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空气污染
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Immunology
·
2022
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IF 8.786
Yang Yong-Shi,Cao Meng-Da,Wang An,Liu Qing-Mei,Zhu Dan-Xuan,Zou Ying,Ma Ling-Ling,Luo Min,Shao Yang,Xu Dian-Dou,Wei Ji-Fu,Sun Jin-Lyu
Background: Allergic respiratory diseases have increased dramatically due to air pollution over the past few decades. However, studies are limited on the effects of inorganic components and particulate matter with different particle sizes in smog on allergic diseases, and the possible molecular mechanism of inducing allergies has not been thoroughly studied.Methods: Four common mineral elements with different particle sizes in smog particles were selected, including Al2O3, TiO2, Fe2O3, and SiO2. We studied the relationship and molecular mechanism of smog particle composition, particle size, and allergic reactions using mast cells, immunoglobulin E (IgE)-mediated passive cutaneous anaphylaxis (PCA) model, and an ovalbumin (OVA)-induced asthmatic mouse model in vitro and in vivo, combined with transmission electron microscopy, scanning transmission X-ray microscopy analysis, and transcriptome sequencing.Results: Only 20 nm SiO2 particles significantly increased β-hexosaminidase release, based on dinitrophenol (DNP)-human serum albumin (HSA) stimulation, from IgE-sensitized mast cells, while other particles did not. Meanwhile, the PCA model showed that Evan’s blue extravasation in mice was increased after treatment with nano-SiO2 particles. Nano-SiO2 particles exposure in the asthmatic mouse model caused an enhancement of allergic airway inflammation as manifested by OVA-specific serum IgE, airway hyperresponsiveness, lung inflammation injury, mucous cell metaplasia, cytokine expression, mast cell activation, and histamine secretion, which were significantly increased. Nano-SiO2 particles exposure did not affect the expression of FcϵRI or the ability of mast cells to bind IgE but synergistically activated mast cells by enhancing the mitogen-activated protein kinase (MAPK) signaling pathway, especially the phosphorylation levels of the extracellular signal-regulated kinase (ERK)1/2. The ERK inhibitors showed a significant inhibitory effect in reducing β-hexosaminidase release.Conclusion: Our results indicated that nano-SiO2 particles stimulation might synergistically activate IgE-sensitized mast cells by enhancing the MAPK signaling pathway and that nano-SiO2 particles exposure could exacerbate allergic inflammation. Our experimental results provide useful information for preventing and treating allergic diseases.
研究领域:
免疫学
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环境健康
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分子生物学
·
过敏与哮喘
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）