Pollution Level and Distribution of PCDD/PCDF Congeners between Gas Phase and Particulate Phase in early Spring Air of Dalian, China

2011 ◽  
Vol 71-78 ◽  
pp. 2679-2682
Author(s):  
Xiu Hua Zhu ◽  
Song Tao Qin ◽  
Qian Xu ◽  
Yu Wen Ni ◽  
Ji Ping Chen ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gaseous Phase ◽  
High Volume ◽  
Ambient Air ◽  
Early Spring ◽  
Pollution Level ◽  
Particulate Phase ◽  
Spring Season ◽  
International Standard

Ambient air of Dalian was sampled with active high-volume air samplers in early spring time. The concentrations and the congeners between gas phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) in the air were measured. Samples analysis results showed that the concentration of PCDD/Fs in particulate phase was higher than that in gas phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4. The main sources of atmospheric PCDD/Fs in Dalian early spring season were coal-related source. The total I-TEQ in gaseous phase and particulate phase was 30.3 and 143.6 fg m-3, respectively. The I-TEQ of Dalian early spring atmosphere was lower than international standard, the atmospheric quality in Dalian was better.

Levels and Distributions of Six Toxic PAHs in the Urban Air of Dalian, China During Heating Periods

2012 ◽  
Vol 518-523 ◽  
pp. 2572-2575
Author(s):  
Xiu Hua Zhu ◽  
Cheng Zhi Zhou ◽  
Ran Ran ◽  
Zhen Wang ◽  
Xin Dong Ma ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gaseous Phase ◽  
Total Concentration ◽  
High Volume ◽  
Urban Air ◽  
Particulate Phase ◽  
High Volume Sampler

Superscript text Superscript textThe concentration of six potential carcinogenic compounds (3-Methylcholanthrene, Dibenz(a,h)acridine, Dibenz(a,i)acridine, Dibenzo(a,e)pyrene, Dibenzo(a,h)pyrene, Dibenzo(a,i)pyrene ) in the urban air of Dalian, China were monitored from November 2009 to March 2010 with active high-volume sampler. They were detected in gaseous phase and particulate phase, respectively. The total concentration of them was 563.2 pg m-3, and they were mainly found in particulate phase with the concentration of 540.5 pg m-3 while the concentration in the gas phase only was 22.7 pg m-3. The concentration of them changed apparently in different month.

scholarly journals Evaluation of atmospheric concentrations of dl-PCBs comparing to PCDD/F compounds in Istanbul, Turkey

2018 ◽  
Vol 21 (2) ◽  
pp. 113-123
Keyword(s):  
Gas Phase ◽  
Meteorological Factors ◽  
Winter Season ◽  
High Volume ◽  
Ambient Air ◽  
Particle Phase ◽  
Particulate Phase ◽  
Air Samples ◽  
Atmospheric Concentrations ◽  
Homolog Group

<p>In this study, the seasonal variation of atmospheric concentrations of PCDD/F and Dl-PCB and the effect of meteorological factors on concentration were investigated. Ambient air samples were collected monthly between May 2011 and October 2013 by using high volume samplers. Based on these samples, average PCDD/F and dl-PCB concentrations were obtained as 1482 fg/m3 and 4983 fg/m3 respectively. PCDD/F congeners did show seasonal variations. 58% share in total PCDD/Fs belongs to winter season while 4% to summer season. No significant seasonal change has been observed for dl-PCBs. 92% (1397 fg/m3) of PCDD/Fs were detected in particulate phase while 20% (926 fg/m3) of dl-PCBs were found in particulate phase. Strong negative correlations were obtained between all homolog groups and T, UV, SR. Correlation between five-chlorinated dl-PCBs, the most abandoned homolog group, with T, UV and SR generated positive meaningful correlation. No meaningful correlations were observed with other parameters. Correlations with particle phase were found to be more meaningful compared to gas phase for both PCDD/Fs and dl-PCBs.</p>

scholarly journals Polyfluoroalkyl compounds in the Canadian Arctic atmosphere

2011 ◽  
Vol 8 (4) ◽  
pp. 399 ◽  
Author(s):  
Lutz Ahrens ◽  
Mahiba Shoeib ◽  
Sabino Del Vento ◽  
Garry Codling ◽  
Crispin Halsall
Keyword(s):  
Gas Phase ◽  
Environmental Concern ◽  
Canadian Arctic ◽  
High Volume ◽  
Ambient Air ◽  
Coast Guard ◽  
The Arctic ◽  
Particle Phase ◽  
Method Performance ◽  
Arctic Atmosphere

Environmental contextPerfluoroalkyl compounds are of rising environmental concern because of their ubiquitous distribution in remote regions like the Arctic. The present study quantifies these contaminants in the gas and particle phases of the Canadian Arctic atmosphere. The results demonstrate the important role played by gas–particle partitioning in the transport and fate of perfluoroalkyl compounds in the atmosphere. AbstractPolyfluoroalkyl compounds (PFCs) were determined in high-volume air samples during a ship cruise onboard the Canadian Coast Guard Ship Amundsen crossing the Labrador Sea, Hudson Bay and the Beaufort Sea of the Canadian Arctic. Five PFC classes (i.e. perfluoroalkyl carboxylates (PFCAs), polyfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs)) were analysed separately in the gas phase collected on PUF/XAD-2 sandwiches and in the particle phase on glass-fibre filters (GFFs). The method performance of sampling, extraction and instrumental analysis were compared between two research groups. The FTOHs were the dominant PFCs in the gas phase (20–138 pg m–3), followed by the FOSEs (0.4–23 pg m–3) and FOSAs (0.5–4.7 pg m–3). The PFCAs could only be quantified in the particle phase with low levels (<0.04–0.18 pg m–3). In the particle phase, the dominant PFC class was the FOSEs (0.3–8.6 pg m–3). The particle-associated fraction followed the general trend of: FOSEs (~25 %) > FOSAs (~9 %) > FTOHs (~1 %). Significant positive correlation between ∑FOSA concentrations in the gas phase and ambient air temperature indicate that cold Arctic surfaces, such as the sea-ice snowpack and surface seawater could be influencing FOSAs in the atmosphere.

scholarly journals Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 264 ◽  
Author(s):  
Giovanni Lonati ◽  
Federico Riva
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Regional Scale ◽  
High Volume ◽  
Ambient Air ◽  
Northern Italy ◽  
Traffic Emissions ◽  
Gaseous Pollutants ◽  
Po Valley ◽  
Concentration Levels

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO2, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO2 and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH3 ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO2 and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas.

scholarly journals Amines in boreal forest air at SMEAR II station in Finland

2018 ◽  
Vol 18 (9) ◽  
pp. 6367-6380 ◽  
Author(s):  
Marja Hemmilä ◽  
Heidi Hellén ◽  
Aki Virkkula ◽  
Ulla Makkonen ◽  
Arnaud P. Praplan ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Gas Phase ◽  
Particle Number ◽  
Detection Limits ◽  
Ambient Air ◽  
Monthly Means ◽  
Ammonium Ions ◽  
Quadrupole Mass ◽  
Concentration Data ◽  
Diurnal Variability

Abstract. We measured amines in boreal forest air in Finland both in gas and particle phases with 1 h time resolution using an online ion chromatograph (instrument for Measuring AeRosols and Gases in Ambient Air – MARGA) connected to an electrospray ionization quadrupole mass spectrometer (MS). The developed MARGA-MS method was able to separate and detect seven different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA), and butylamine (BA). The detection limits of the method for amines were low (0.2–3.1 ng m−3), the accuracy of IC-MS analysis was 11–37 %, and the precision 10–15 %. The proper measurements in the boreal forest covered about 8 weeks between March and December 2015. The amines were found to be an inhomogeneous group of compounds, showing different seasonal and diurnal variability. Total MMA (MMA(tot)) peaked together with the sum of ammonia and ammonium ions already in March. In March, monthly means for MMA were < 2.4 and 6.8 ± 9.1 ng m−3 in gas and aerosol phases, respectively, and for NH3 and NH4+ these were 52 ± 16 and 425 ± 371 ng m−3, respectively. Monthly medians in March for MMA(tot), NH3, and NH4+ were < 2.4, 19 and 90 ng m−3, respectively. DMA(tot) and TMA(tot) had summer maxima indicating biogenic sources. We observed diurnal variation for DMA(tot) but not for TMA(tot). The highest concentrations of these compounds were measured in July. Then, monthly means for DMA were < 3.1 and 8.4 ± 3.1 ng m−3 in gas and aerosol phases, respectively, and for TMA these were 0.4 ± 0.1 and 1.8 ± 0.5 ng m−3. Monthly medians in July for DMA were below the detection limit (DL) and 4.9 ng m−3 in gas and aerosol phases, respectively, and for TMA these were 0.4 and 1.4 ng m−3. When relative humidity of air was > 90 %, gas-phase DMA correlated well with 1.1–2 nm particle number concentration (R2=0.63) suggesting that it participates in atmospheric clustering. EA concentrations were low all the time. Its July means were < 0.36 and 0.4 ± 0.4 ng m−3 in gas and aerosol phases, respectively, but individual concentration data correlated well with monoterpene concentrations in July. Monthly means of PA and BA were below detection limits at all times.

Analysis of chlorinated hydrocarbons in gas phase using a portable membrane inlet mass spectrometer

2016 ◽  
Vol 8 (36) ◽  
pp. 6607-6615 ◽  
Author(s):  
Stamatios Giannoukos ◽  
Boris Brkić ◽  
Stephen Taylor
Keyword(s):  
Gas Phase ◽  
Mass Spectrometer ◽  
Gaseous Phase ◽  
Chlorinated Hydrocarbons ◽  
Volatile Chlorinated Hydrocarbons ◽  
First Time

A compact portable membrane inlet mass spectrometer (MIMS) has been used for the first time to detect and monitor, both qualitatively and quantitatively, volatile chlorinated hydrocarbons in the gaseous phase.

Improved synthesis and crystal structure of the parent 1,3,5-trisilacyclohexane

2016 ◽  
Vol 71 (1) ◽  
pp. 77-79 ◽  
Author(s):  
Eugen Weisheim ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Gaseous Phase ◽  
Chair Conformation ◽  
Gas Electron Diffraction ◽  
State Structure ◽  
Synthesis And Crystal Structure ◽  
Bond Lengths

AbstractThe crystal structure and an improved synthesis of 1,3,5-trisilacyclohexane are reported. The solid state structure is compared with the reported structure determined in the gas phase by gas electron diffraction (GED). 1,3,5-Trisilacyclohexane adopts a chair conformation in the solid state. The Si–C bond lengths as well as all angles of 1,3,5-trisilacyclohexane in the solid state have similar dimensions compared to the structure in the gaseous phase.

scholarly journals Scavenging ratio of polycyclic aromatic compounds in rain and snow at the Athabasca oil sands region

2014 ◽  
Vol 14 (13) ◽  
pp. 19395-19429
Author(s):  
L. Zhang ◽  
I. Cheng ◽  
D. Muir ◽  
J.-P. Charland
Keyword(s):  
Gas Phase ◽  
Aromatic Compounds ◽  
Oil Sands ◽  
Polycyclic Aromatic Compounds ◽  
Particulate Phase ◽  
Athabasca Oil Sands ◽  
Polycyclic Aromatic ◽  
Alkylated Pahs ◽  
Snow Samples ◽  
Air Concentrations

Abstract. Athabasca oil sands industry in northern Alberta, Canada is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes, in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during May 2011 to August 2012 were analyzed to generate a database of scavenging (or washout) ratios (Wt) for PACs scavenged by both snow and rain. Median precipitation and air concentrations of parent PAHs over the May 2011 to August 2012 period ranged from 0.3–184.9 (chrysene) ng L−1 and 0.01–3.9 (naphthalene) ng m−3, respectively, which were comparable to literature values. Higher concentrations in precipitation and air were observed for alkylated PAHs and dibenzothiophenes. The median precipitation and air concentrations were 11.3–646.7 (C3-fluoranthene/pyrene) ng L−1 and 0.21–16.9 (C3-naphthalene) ng m−3, respectively, for alkylated PAHs, and 8.5–530.5 (C4-dibenzothiophene) ng L−1 and 0.13–6.6 (C2-dibenzothiophene) ng m−3 for dibenzothiophenes and their alkylated derivatives. Median Wt over the measurement period were 6100–1.1 × 106 from snow scavenging and 350–2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations. But Wt for acenaphthylene in snow samples was 2–7 times higher. Some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging was ∼9 times greater than rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and Henry's Law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. This study verified findings from a previous study of Wang et al. (2014) which suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amount, and also provided new knowledge on the scavenging of gas-phase PACs by snow and rain.

Exploring Air Pollution and COVID-19 Linkages in South Asia

2021 ◽  
Author(s):  
Muthukumara Mani ◽  
Takahiro Yamada
Keyword(s):  
Air Pollution ◽  
South Asia ◽  
Measurement Errors ◽  
Ambient Air ◽  
The Body ◽  
Ambient Air Pollution ◽  
Cellular Damage ◽  
Pollution Level ◽  
Form Analysis ◽  
Risk Of Death

South Asia is at the epicenter of the global air pollution problems and still evolving in COVID-19 cases and fatalities. There is growing evidence of increased rates of COVID-19 in areas with high levels of air pollution. Air pollution is found to cause cellular damage and inflammation throughout the body and has been linked to higher rates of diseases, including cancer, heart disease, stroke, diabetes, asthma, and other comorbidities. All these conditions also potentially increase the risk of death in COVID-19 patients. The causal link between the exposure to air pollution and COVID-19 is still under investigation around the world, underpinned by rigorous scientific research and peer-review processes. However, in terms of the approach after a careful review of the literature, the instrumental variable (IV) approach is a prospective candidate to establish causality in a reduced-form analysis to overcome endogeneity and measurement errors of air pollution level. An analysis, therefore, using sufficiently anonymized individual and household level information on COVID-19, household air pollution, and other individual and household socioeconomic endowments in the same primary sampling unit (PSU) of the individual and household survey would be necessary to establish the causality. The PSU data are usually available from demographic health surveys (DHS) with randomly displaced location information to maintain anonymity. Also, for the instrument of the exposure to ambient air pollution, the use of thermal inversions is suggested conditional on weather-related variables—for example, temperature, precipitation, wind velocity and direction, and humidity.

Ambient Air Quality Monitoring Studies in Four Specific Location of Tamilnadu, India

2019 ◽  
pp. 677-683
Author(s):  
Mageshkumar P ◽  
Ramesh S ◽  
Angu Senthil K
Keyword(s):  
Air Quality ◽  
Quality Index ◽  
High Volume ◽  
Ambient Air ◽  
Quality Parameters ◽  
Air Quality Index ◽  
Gaseous Pollutants ◽  
Ambient Air Quality ◽  
Air Sampler

A comprehensive study on the air quality was carried out in four locations namely, Tiruchengode Bus Stand, K.S.R College Campus, Pallipalayam Bus Stop and Erode Government Hospital to assess the prevailing quality of air. Ambient air sampling was carried out in four locations using a high volume air sampler and the mass concentrations of PM10, PM2.5, SO2, NOX and CO were measured. The analyzed quality parameters were compared with the values suggested by National Ambient Air Quality Standards (NAAQS). Air quality index was also calculated for the gaseous pollutants and for Particulate Matters. It was found that PM10 concentration exceeds the threshold limits in all the measured locations. The higher vehicular density is one of the main reasons for the higher concentrations of these gaseous pollutants. The air quality index results show that the selected locations come under moderate air pollution.

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