AbstractThe roles of PM2.5-induced mitochondrial damage and oxidative stress on mast cell degranulation were examined in vitro. Mast cells were treated with suspensions of PM2.5 in Dulbecco’s modified Eagle’s medium at concentrations from 25 to 200?mg/L in the absence or presence of 10?mmol/L N-acetyl-L-cysteine. Biological effects and mitochondrial function were assessed by determining cell viability, β-hexosaminidase release, interleukin-4 secretion, reactive oxygen species generation, adenosine triphosphate production, potential alteration of mitochondrial membrane, and activities of mitochondrial electron transport chain complexes I and III. Exposure of mast cells to PM2.5 induced reduction of adenosine triphosphate production, collapse of mitochondrial membrane potential, and inhibition of the activity of complex III. Co-treatment of mast cells exposed to PM2.5 with N-acetyl-L-cysteine attenuated cytotoxicity and the production of reactive oxygen species, and decreased the release of β-hexosaminidase and interleukin-4. Evidently, PM2.5-induced oxidative stress plays an essential role in mitochondrial toxicity and mast cell activation. 相似文献
Concentrations of total suspended particulate matter, particulate matter with aerodynamic diameter <2.5 μm (PM2.5), particulate matter <10 μm (PM10), and fallout dust were measured at the Iranian Gol-E-Gohar Mining and Industrial Facility. Samples were characterized in terms of mineralogy, morphology, and oxidative potential. Results show that indoor samples exceeded the 24-h PM2.5 and PM10 mass concentration limits (35 and 150 µg m?3, respectively) set by the US National Ambient Air Quality Standards. Calcite, magnetite, tremolite, pyrite, talc, and clay minerals such as kaolinite, vermiculite, and illite are the major phases of the iron ore PM. Accessory minerals are quartz, dolomite, hematite, actinolite, biotite, albite, nimite, laumontite, diopside, and muscovite. The scanning electron microscope structure of fibrous-elongated minerals revealed individual fibers in the range of 1.5 nm to 71.65 µm in length and 0.2 nm to 3.7 µm in diameter. The presence of minerals related to respiratory diseases, such as talc, crystalline silica, and needle-shaped minerals like amphibole asbestos (tremolite and actinolite), strongly suggests the need for detailed health-based studies in the region. The particulate samples show low to medium oxidative potential per unit of mass, in relation to an urban road side control, being more reactive with ascorbate than with glutathione or urate. However, the PM oxidative potential per volume of air is exceptionally high, confirming that the workers are exposed to a considerable oxidative environment. PM released by iron ore mining and processing activities should be considered a potential health risk to the mine workers and nearby employees, and strategies to combat the issue are suggested. 相似文献
We estimate the effect of short-term air pollution exposure (PM2.5 and ozone) on several categories of crime, with a particular emphasis on aggressive behavior. To identify this relationship, we combine detailed daily data on crime, air pollution, and weather for an eight-year period across the United States. Our primary identification strategy employs extremely high dimensional fixed effects and we perform a series of robustness checks to address confounding variation between temperature and air pollution. We find a robust positive effect of increased air pollution on violent crimes, and specifically assaults, but no relationship between increases in air pollution and property crimes. The effects are present in and out of the home, at levels well below Ambient Air Pollution Standards, and PM2.5 effects are strongest at lower temperatures. The results suggest that a 10% reduction in daily PM2.5 and ozone could save $1.4 billion in crime costs per year, a previously overlooked cost associated with pollution. 相似文献
Fine particulate matter (PM2.5) levels, carbon dioxide (CO2) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m3, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m3). The CO2 concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm3, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R2 = 0.834) was observed between passenger numbers and CO2 levels, with each passenger contributing approximately 7.7–9.8 ppm of CO2. The real-time measurements of PM2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM2.5 levels and PNC. Assessment of the risk associated with PM2.5 exposure revealed that children are most severely affected by PM2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk. 相似文献
The Eulerian Chemistry-Transport Model BelEUROS was used to calculate the concentrations of airborne PM10 and PM2.5 over Europe. Both primary as well as secondary particulate matter in the respirable size-range was taken into account. Especially PM2.5 aerosols are often formed in the atmosphere from gaseous precursor compounds. Comprehensive computer codes for the calculation of gas phase chemical reactions and thermodynamic equilibria between compounds in the gas-phase and the particulate phase had been implemented into the BelEUROS-model. Calculated concentrations of PM10 and PM2.5 are compared to observations, including both the spatial and daily, temporal distribution of particulate matter in Belgium for certain monitoring locations and periods. The concentrations of the secondary compounds ammonium, nitrate and sulfate have also been compared to observed values. BelEUROS was found to reproduce the observed concentrations rather well. The model was applied to assess the contribution of emissions derived from the sector agriculture in Flanders, the northern part of Belgium, to PM10- and PM2.5-concentrations. The results demonstrate the importance of ammonia emissions in the formation of secondary particulate matter. Hence, future European emission abatement policy should consider more the role of ammonia in the formation of secondary particles. 相似文献
In 2004, airborne particulate matter (PM) was collected for several aerosol episodes occurring in the southern region of Taiwan.
The particulate samples were taken using both a MOUDI (Micro-orifice Uniform Deposit Impactor) and a nano-MOUDI sampler. These
particulate samples were analyzed for major water-soluble ionic species with an emphasis to characterize the mass concentrations
and distributions of these ions in the ambient ultrafine (PM0.1, diameter <0.1 μm) and nano mode (PMnano, diameter <0.056 μm) particles. Particles collected at the sampling site (the Da-Liao station) on the whole exhibited a typical
tri-modal size distribution on mass concentration. The mass concentration ratios of PMnano/PM2.5, PM0.1/PM2.5, and PM1/PM2.5 on average were 1.8, 2.9, and 71.0%, respectively. The peak mass concentration appeared in the submicron particle mode (0.1 μm < diameter <1.0 μm).
Mass fractions (percentages) of the three major water-soluble ions (nitrate, sulfate, and ammonium) as a group in PMnano, PM0.1, PM1, and PM2.5 were 18.4, 21.7, 50.0, and 50.7%, respectively. Overall, results from this study supported the notion that secondary aerosols
played a significant role in the formation of ambient submicron particulates (PM0.1−1). Particles smaller than 0.1 μm were essentially basic, whereas those greater than 2.5 μm were neutral or slightly acidic.
The neutralization ratio (NR) was close to unity for airborne particles with diameters ranging from 0.18 to 1 μm. The NRs
of these airborne particles were found strongly correlated with their sizes, at least for samples taken during the aerosol
episodes under study. Insofar as this study is exploratory in nature, as only a small number of particulate samples were used,
there appears to be a need for further research into the chemical composition, source contribution, and formation of the nano
and ultrafine mode airborne particulates. 相似文献
The objective of this paper is to propose a hybrid approach for the source apportionment of primary and secondary species of PM2.5 in the city of Tangshan. The receptor-based PMF (Positive Matrix Factorization) is integrated with the emission inventory (EI) to form the first hybrid method for the source apportionment of the primary species. The hybrid CAMx-PSAT-CP (Comprehensive Air Quality Model with Extensions–Particulate Source Apportionment Technology–Chemical Profile) approach is then proposed and used for the source apportionment of the secondary species. The PM2.5 sources identified for Tangshan included the soil dust, the metallurgical industry, power plants, coalfired boilers, vehicles, cement production, and other sources. It is indicated that the PM2.5 pollution is a regional issue. Among all the identified sources, the metallurgy industry was the biggest contribution source to PM2.5, followed by coal-fired boilers, vehicles and soil dust. The other-source category plays a crucial role for PM2.5, particularly for the formation of secondary species and aerosols, and these other sources include non-specified sources such as agricultural activities, biomass combustion, residential emissions, etc. The source apportionment results could help the local authorities make sound policies and regulations to better protect the citizens from the local and regional PM2.5 pollution. The study also highlights the strength of utilizing the proposed hybrid approaches in the identification of PM2.5 sources. The techniques used in this study show considerable promise for further application to other regions as well as to identify other source categories of PM2.5.
PM2.5 has become an important environmental issue in Taiwan during the past few years. Moreover, electricity increased significantly during the summertime and TTPP generated by coal burning base is the main electricity provider in central Taiwan. Therefore, summer season has become the main research target in this study. The ambient air concentrations of particulate matter PM2.5 and PM10 collected by using VAPS at a mixed characteristic sampling site were studied in central Taiwan. The results indicated that the average daytime PM2.5 and PM10 particulate concentrations were occurred in May and they were 44.75 and 57.77 µg/m3 in this study. The results also indicated that the average nighttime PM2.5 and PM10 particulate concentrations were occurred in June and they were 38.19 and 45.79 µg/m3 in this study. The average PM2.5/PM10 ratios were 0.7 for daytime, nighttime and 24-h sampling periods in the summer for this study. This value was ranked as the lowest ratios when compared to the other seasons in previous study. Noteworthy, the results further indicated that the metallic element Pb has the mean highest concentrations for 24-h, daytime and nighttime sampling periods when compared to those of the other metallic elements (Ni, Cu, Zn and Cd). The average mean highest metallic Pb concentrations in PM10 were 110.7, 203.0 and 207.2 ng/m3 for 24-h, daytime and nighttime sampling periods in this study. And there were 59.53, 105.2 and 106.6 ng/m3 for Pb in PM2.5 for 24-h, daytime and nighttime sampling periods, respectively. Moreover, the results further indicated that mean metallic element Pb concentrations on PM2.5 and PM10 were all higher than those of the other elements for 24 h, day and nighttime. 相似文献
The paucity of data on air pollution indices in Nigeria prompted us to commence a national screening exercise regarding particulate matter loads. Six potential megacities (Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt) representing the six geographical zones in Nigeria were chosen for the study. Sampling was achieved using a ‘Gent’ stacked filter unit sampler capable of collecting fractions of particulate matter with sizes of <10-μm and <2.5-μm simultaneously. The mean values for PM10 are 550, 35, 87, 340, 246 and 130 μg m?3 while for PM2.5 the mean values are 100, 14, 25, 67, 20 and 30 μg m?3 respectively for Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt. Except for Abuja, the daily PM10 mass loads exceeded the World Health Organization (WHO) guidelines daily limit where as the PM2.5 values were within the WHO guideline limit. Their correlation matrix result indicates that some PM2.5 fractions mass fractions were strongly correlated than the PM10 fractions probably due to their long range transport potentials. Further work is in progress to determine the elemental profiles of both particulate fractions collected. 相似文献
