PAHs were analyzed in samples of atmospheric aerosols and suspended matter in seawater collected in the Sea of Japan, Sea of Okhotsk and the North-Western Pacific in June-July 2012. The concentrations of Sigma(15) PAH...
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PAHs were analyzed in samples of atmospheric aerosols and suspended matter in seawater collected in the Sea of Japan, Sea of Okhotsk and the North-Western Pacific in June-July 2012. The concentrations of Sigma(15) PAHs in the suspended matter of seawater ranged between 1984.7 pg/L to 30260.3 pg/L. The concentration of Sigma(14) PAHs in marine aerosols ranged from 17.09 pg/m(3) on June 19-22, 2012 in the northern part of the Sea of Japan, the La Perouse Strait to 142.47 pg/m(3) on June 25-28, 2012 near middle Kuril Islands. The results of diagnostic ratios analysis indicate that the primary sources of PAH are pyrogenic. This paper discusses the main anthropogenic (coal-fired power plants and population) and natural sources (wildfires) of PAHs and their effect on the concentration of these compounds in the marine air and suspended matter of seawater. Long-range atmospheric transport of PAHs from the continent to the ocean is shown using HYSPLIT backward trajectories. Active fire products (MODIS and VIIRS) data were used to build a regression model. The model as a whole explains 58% and 75% of the Sigma 5-ring PAHs and BaP variations in seawater in June-July 2012, respectively. The analysis shows that anthropogenic sources were not a significant contribution factor for PAHs in the seawater at the Sea of Japan during this period.
Air pollution and global warming are two of the greatest threats to human and animal health and political stability. The primary global warming pollutants are, in order, carbon dioxide gas, fossil-fuel plus biofuel so...
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Air pollution and global warming are two of the greatest threats to human and animal health and political stability. The primary global warming pollutants are, in order, carbon dioxide gas, fossil-fuel plus biofuel soot particles, methane gas, 4, 6 - 10 halocarbons, tropospheric ozone, and nitrous oxide gas. About half of actual global warming to date is being masked by cooling aerosol particles. Increased concentrations of ozone and fine particulate matter (PM2.5) since preindustrial times reflect increased emissions, but also contributions of past climate change. Recent analyses have shown that reducing black carbon (BC) emissions, using known control measures, would reduce global warming and delay the time when anthropogenic effects on global temperature would exceed 2°C. Likewise, cost-effective control measures on ammonia, an important agricultural precursor gas for secondary inorganic aerosols (SIA), would reduce regional eutrophication and PM concentrations in large areas of Europe, China, and the USA. Thus, there is much that could be done to reduce the effects of atmospheric PM on the climate and the health of the environment and the human population.
Electronic cigarettes (e-cigarettes, EC) form an aerosol from the heating element and liquid-containing cartridge. The heating element aerosolizes the refill solutions (e-liquids) when the power source of e-cigarette ...
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Electronic cigarettes (e-cigarettes, EC) form an aerosol from the heating element and liquid-containing cartridge. The heating element aerosolizes the refill solutions (e-liquids) when the power source of e-cigarette is pressed. E-liquids consist of combinations of propylene glycol, glycerine, nicotine and flavouring ingredients. Puffing activates the battery-operated heating element in the atomizer and will produce smoke that is similar to conventional cigarette (CC). This study evaluated the chemical composition of e-liquid and aerosol samples available in Malaysia. We analyzed the volatile organic compounds in e-liquids and the aerosols samples from EC using gas chromatography mass spectrometer. Seventy-two EC e-liquids were analyzed through different flavours from more than 60 brands. Samples consisted of 32 nicotine-free (0 mg) and 40 nicotine-containing refill solutions (3 - 12 mg). Overall, 116 compounds were identified from EC e-liquids. On the other hand, 275 compounds were identified from their resultant aerosol samples. There were 42 compounds found in both e-liquids and aerosols. Seven compounds were only found in e-liquids and 38 compounds were only found in aerosols. Propylene glycol was found in all of the e-liquid and aerosol samples. Glycerin was found in 99% of the e-liquid and 100% of aerosol samples. At least 60% of the EC e-liquids and the resultant aerosol contain piperidine, butanoic acid ethyl ester and nicotine. It was also found that at least 9 out of 35 nicotine free labeled e-liquids contain nicotine. Some of these compounds were known to be detrimental to health and were detected in aerosol although they were not present in e-liquids. While some of the compounds are flavouring ingredients, it is necessary to evaluate its long-term effects on EC users.
The properties of summer radiation and aerosols were studied at Xinzhou,a suburban site on the North China Plain(NCP)by using ground-based measurements in *** radiation detections under clear and cloudy skies showed t...
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The properties of summer radiation and aerosols were studied at Xinzhou,a suburban site on the North China Plain(NCP)by using ground-based measurements in *** radiation detections under clear and cloudy skies showed that longwave radiation presented a sigmate pattern,with a maximum of 392.6 W m-2at 1700 local standard time(LST)associated with the cloud radiative forcing,and a minimum of 360.0 W m-2at 0600 LST when the lowest surface temperature(17.1°C)*** radiation,including global,direct,diffuse,photosynthetically active,ultraviolet-A,and ultraviolet-B,exhibited a single peak at^1300 LST.A bimodal size distribution,with fine mode aerosols showing a peak between 0.1 and 0.2μm and coarse mode aerosols showing a peak at^5μm,was observed at *** dominant aerosol type was black carbon coating on coarse particles(85.7%)for the cases with aerosol optical depth at 400 nm(AOD)greater than 0.4,leading to a lower single scattering albedo(0.81)than the typical value(~0.90)at the other stations on the *** mean values of EAE and AAE(extinction and absorption?ngstr?m exponent,respectively)were 1.14±0.15 and 0.58±0.28 for the aerosol *** average of instantaneous aerosol direct radiative forcing at the bottom of the atmosphere was-138.9±33.0 W m-2for the cases with AOD>*** results in this study are expected to improve understanding at suburban sites on the NCP of aerosol properties and their impacts on regional radiation budgets.
In this study, a photothermal interferometer was developed, based on a folded-Jamin polarization instrument with refractive-index sensitive configuration, in order to characterize light-absorbing aerosols. The feasibi...
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In this study, a photothermal interferometer was developed, based on a folded-Jamin polarization instrument with refractive-index sensitive configuration, in order to characterize light-absorbing aerosols. The feasibility of our interferometric technique was demonstrated by performing photothermal spectroscopy characterizing spark-generated black carbon particles with atmospherically relevant concentrations and atmospheric aerosols in a metropolitan area. The sensitivity of this interferometric system for both laboratory-generated aerosols and atmospheric aerosols was similar to 1 (mu g/m(3))/mu V, which is sufficient for the monitoring of black carbon aerosol in urban areas.
The physical and chemical analysis of aerosols using reliable and physically traceable methods is important for the thorough investigation of airborne particles to support a better understanding of their origin as wel...
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Tracing potential source regions of aerosols/dust is a key factor in understanding the atmospheric circulation regimes. In this context, Nd and Sr isotopes in continental fine sediments have been used as tracers (or f...
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Tracing potential source regions of aerosols/dust is a key factor in understanding the atmospheric circulation regimes. In this context, Nd and Sr isotopes in continental fine sediments have been used as tracers (or fingerprints) of dust found in deep cores retrieved from the Antarctic ice sheets. In order to demonstrate the utility of radiogenic isotopes as dust fingerprint we have conducted atmospheric samplings from latitude 30 degrees S to 64 degrees S, over the Southwestern Atlantic Ocean, the Southern Ocean/Drake passage and coastal waters of the northern Antarctic Peninsula. We aimed at comparing the radiogenic isotope signature of the collected aerosols and their most likely sources as described in the literature. Aerosol samples were collected during oceanographic cruises carried out in 2010, 2011 and 2012 by the Brazilian Antarctic Program. Measured isotope ratios Sr-87/Sr-86 and Nd-143/Nd-144 were compared with inventories for Patagonia, Australia and Antarctica. In our study, origins of aerosols over sea were attributed to: (1) the Patagonian influence over the Argentine continental shelf;and (2) in the Southern Ocean where prevails a mix of dust sources from Patagonia, Australia and rock outcrops existing in the Antarctic continent.
The hygienic risk associated with evaporative cooling systems in Germany is currently only assessed by determining concentrations of Legionella spp. in the corresponding cooling waters. Relevant for the health risk is...
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The hygienic risk associated with evaporative cooling systems in Germany is currently only assessed by determining concentrations of Legionella spp. in the corresponding cooling waters. Relevant for the health risk is however the load of Legionella in emitted aerosols. In this work aerosol emissions from four industrial cooling systems (A - D) were analyzed. A microbiological air bioburden factor (MABF) is suggested to be useful to assess the overall microbiological load of emitted air and to judge the efficiency of droplet separation and overall microbiological retention. Whereas the MABF by itself only serves as a technical quality assurance (QA) parameter, the hygienic relevance has to be seen in combination with the assessment of Legionella either contained in the aerosol or in the cooling water. Plate counting of colonies was an appropriate method to quantify Legionella spp. in aerosols given the short time of flight at the chosen sampling locations and resulting low risk of desiccation. qPCR data on the other hand proved more reproducible than the culture approach to quantify Legionella spp. concentrations in cooling water-. The application of qPCR also allowed to assess the relative proportion of Legionella pneumophila within the total pool of Legionella which adds epidemiological relevance to risk assessment. A traffic light system was proposed to guide interpretation of qPCR data. The four industrial systems greatly differed in all measured parameters leading to different associated risks.
Electronic nicotine delivery systems (ENDS) are a rapidly growing global market advertised as a safer alternative to combustible cigarettes. However, comprehensive investigations of END aerosol physicochemical and tox...
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Electronic nicotine delivery systems (ENDS) are a rapidly growing global market advertised as a safer alternative to combustible cigarettes. However, comprehensive investigations of END aerosol physicochemical and toxicological properties have not been fully explored across brands to assess relative safety. In this study, we evaluated aerosols collected from three ENDS - Juul Fruit Medley (5% nicotine), Logic Power (2.4% nicotine), and Mistic (1.8% nicotine). ENDS aerosols were generated using standard machine puffing regimen and collected with a novel fluoropolymer condensation trap. Triple quadrupole-inductively coupled plasma-mass determined the presence of heavy metals in collected aerosols. The toxicological effects of ENDS aerosols on normal human bronchial epithelial cells (NHBE) were investigated using cellular viability, reactive oxygen species, oxidative stress assays, along with DNA damage assessments using the CometChip (c). Results indicated the total metal concentrations within collected ENDS aerosols were higher for Mistic and Logic compared to Juul. Logic Power aerosols elicited higher reactive oxygen species levels than Mistic and Juul in NHBE after 24-h exposure. Similar dose-dependent reductions of cellular viability and total glutathione were found for each exposure. However, Logic and Juul aerosols caused greater single stranded DNA damage compared to Mistic. Our study indicates that regardless of brand, ENDS aerosols are toxic to upper airway epithelial cells and may pose a potential respiratory hazard to occasional and frequent users.
Dust is associated with numerous hazards to the ecosystem;the dust aerosol affects the community health by polluting the breathable air and its effects on the balance of radiant energy are quite important for scientif...
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ISBN:
(纸本)9781728153049
Dust is associated with numerous hazards to the ecosystem;the dust aerosol affects the community health by polluting the breathable air and its effects on the balance of radiant energy are quite important for scientific research. aerosols scatter and absorb solar radiation: some aerosols contribute to the heating of the earth and others to the cooling. With those problems, this research presents the behavior of three selected aerosols: dust, black carbon (BC) and sulfate (SO4). The aerosol optical thickness (AOT) extinction behaviors were analyzed in comparison with the cloud amount and the surface skin temperature. In addition, we have quantitatively analyzed the dust's particulate matter (PM2.5), in the chosen region of interest (RoI). In all cases of this research, in the nearly recent 28 years (from Jan. 1991 to Jul. 2019), the aerosols data source is the second version of the modern-era retrospective analysis for research and applications (MERRA-2). A selection of the focal study region in south-west Asia was due to its location in the world's dust-belt. Goddard interactive online visualization and analysis infrastructure, GIOVANNI, bridged our research objectives to the data;the Geographical Information System (GIS ArcMap) is one of the software tools that has been utilized to treat the map-based results. In results, among the three selected aerosols, the increase of the dust aerosol always associates with the decrease of the cloud amount in all the seasons of the focal region of interest. Regarding the effects of aerosols on earth's energy balance, the upwelling longwave flux at the top of atmosphere under clear sky and no aerosol conditions was analyzed with the same longwave flux under normal conditions. On side of health effects in the focal region of interest, all seasons suffer from the heaviest dust's fine particulate matter (PM2.5). Though there might exist some examples of afforested deserts in Asia, which can be accounted for a good solution to the d
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