Atmospheric 210Pb, 210Po and 210Po/210Pb activity ratio in urban aerosols: temporal variability and impact of biomass burning emission (original) (raw)
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The sources and fate of 210Po in the urban air: A review
Environment International, 2016
The origin of 210 Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the 210 Po/ 210 Pb and 210 Bi/ 210 Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported 210 Po coming from other sources than 222 Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of 210 Po in the urban air. The average doses of 210 Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from 210 Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure.
Survey of (PM2.5) Concentrations in Sari's City Center in 2010
Iranian Journal Of Health Sciences, 2014
Background and purpose: Because of the high traffic flow in the city center in Sari, a walk through survey indicated that the PM2.5 concentrations are likely to be higher than the standards. This study was carried out to determine the level of PM2.5 at the streets' curbsides in the city center in Sari. Materials and Methods: In this cross-sectional study the PM2.5 concentrations were measured in 185 monitoring stations at the curbsides of four main streets in the Sari city centre. 5550 10-s samples were collected using a real time particle monitor. A questionnaire was used to record air pollution related information and data were analyzed by descriptive statistic and ANOVA tests. Results: Mean of PM2.5 concentration was 83µgm-3 and it was two times more than the national one and EPA recommended 24-hour standard (35µgm-3). This study showed that mean of PM2.5 concentration at the street during traffic rush hours in the morning and evening were higher than those measured in the afternoon. Conclusion: Because of the high concentration of PM2.5 in the Sari's city centre that resulted in this study, the 24-hour PM2.5 concentrations are likely to be higher than standards in some days in the city centre in Sari. Therefore, monitoring and control of air pollution are recommended in this city.
Journal of Earth System Science
Studies in the recent past show improved air quality over India during the Covid-19 lockdown. This research attempts to characterize atmospheric aerosols in terms of a and AOD and their transformation over India during the pandemic lockdown. The type and particle distribution of aerosols, including gaseous species for Bve Indian regions were considered. Fine to coarse particle shift was observed in most regions. The northern region observed high Bre counts, implying crop residue burning season during the stringent lockdown. Thiruvananthapuram, in the south, showed an increase in PM, owing to the resumption of mobility post-lockdown. Hyderabad, however; observed increased PM 2.5 (2.79%) and AOD (37.23%) during Phase 1. Maritime (MT) aerosol predominated over Thiruvananthapuram, whereas urban/biomass burning (UBB) type decreased over the eastern region. Contributions from continental average (CA), maritime continental average (MCA), and MT were observed over Hyderabad, post-lockdown. In the central region, MCA was replaced by UBB and mixed type, with isolated episodes of clean continental (CC) and desert dust (DD). During lockdown phases, an increase in O 3 over western, northern, and central regions is attributed to increased temperature and decreased NO 2. A significant correlation with population density (PD) exists with NO 2 (R 2 = 0.75; p \ 0.05), suggesting human mobility as a major contributor to NO 2 in the atmosphere during the lockdown period.
2012
The first simultaneous measurements and analytical data on atmospheric concentrations of PM 2.5 , PM 10 , inorganic constituents, carbonaceous species, and their optical properties (aerosol optical depth, AOD; absorption coefficient, b abs ; mass absorption efficiency, σ abs ; and single scattering albedo, SSA) from an urban site (Kanpur) in the Indo-Gangetic Plain are reported here. Significantly high aerosol mass concentration (>100 μg m −3 ) and AOD (> 0.3) are seen as a characteristic feature throughout the sampling period, from October 2008 to April 2009. The temporal variability in the mass fractions of carbonaceous species (EC, OC, and WSOC) is pronounced during October−January when emissions from biomass burning are dominant and OC is a major constituent (∼30%) of PM 2.5 mass. The WSOC/OC ratio varies from 0.21 to 0.65, suggesting significant contribution from secondary organic aerosols (SOAs). The mass fraction of SO 4 2− in PM 2.5 (Av: 12.5%) exceeds that of NO 3 − and NH 4 + . Aerosol absorption coefficient (@ 678 nm) decreases from 90 Mm −1 (in December) to 20 Mm −1 (in April), and a linear regression analysis of the data for b abs and EC (n = 54) provides a measure of the mass absorption efficiency of EC (9.6 m 2 g −1 ). In contrast, scattering coefficient (@ 678 nm) increases from 98 Mm −1 (in January) to 1056 Mm −1 (in April) and an average mass scattering efficiency of 3.0 ± 0.9 m 2 g −1 is obtained for PM 10 samples. The highest b scat was associated with the dust storm event (April 17, 2009) over northern Iraq, eastern Syria, and southern Turkey; thus, resulting in high SSA (0.93 ± 0.02) during March−April compared to 0.82 ± 0.04 in October−February. These results have implications to large temporal variability in the atmospheric radiative forcing due to aerosols over northern India.
Atmospheric …, 2010
Aerosol (total suspended particulate) samples collected at three diverse locations (urban-commercial, semi-urban and rural-agricultural) in Patiala, India were analyzed for loss on ignition (LO!) and organic tarry matter (OTM) content in ambient air during crop residue burning (CRB) episodes and non-crop residue burning (NCRB) months in [2006][2007]. Results showed high levels of LOI and OTM during wheat and rice crop residue-burning periods at all the sites. Higher levels were obtained during rice crop residue-burning period as compared to the wheat residue-burning period. At semi-urban site, LOI varied between 53 ± 36!lg m-3 and 257 ± 14!lg m-3 constituting 38-78% (w/w) part of the aerosols whereas levels of OTM varied between 0.98 ± 0.11 !lg m-3 and 7.93 ± 2.76 !lg m-3 comprising 0.42-3.28% (w/w) fraction. At rural-agricultural area site, levels of LOI varied between 86 ± 40 !lg m-3 and 293 ± 70~lg m-3 comprising 27-84% (w/w), whereas OTM levels varied between 1.31 ± 0.64 !lg m-3 and 10.09 ± 6.56 !lg m-3 constituting 0.83-2.42% (w/w) fraction of the aerosols. At urban-cum-commercial site, levels ofLOI and OTM varied between 48 ± 23!lg m-3 and 281 ± 152!lg m-3 and 2.53 ± 1.23 !lg m-3 and 17.40 ± 8.50 !lg m-3 , constituting 24-62% (w/w) part of the aerosols, respectively. Results also indicated that OTM and LOI were integral parts of aerosols and their concentrations were influenced by the crop residue burning practices with incorporated effect of vehicular activities in Patiala.
Impact of crop residue burning in Haryana on the air quality of Delhi, India
Heliyon, 2021
Crop residue burning (CRB) over northern India is a major air quality and human health issue. The present study assesses the impact of PM 10 , PM 2.5 , NO 2 and SO 2 , emitted during CRB activities in Haryana on the air quality of Delhi. The transition from pre-burning to burning period, in both rabi and kharif seasons, shows considerable increase in pollutant concentrations. PM 10 and PM 2.5 concentrations exceeded NAAQS limits by 2-3 times, while NO 2 and SO 2 stayed within the limits. MODIS fire observations used to estimate CRB fire counts (confidence !80%) shows that rabi (burning period) fires in Haryana are~3 times higher and more intense than in kharif. Furthermore, backward trajectories shows air mass movement from Haryana, Punjab and Pakistan. Thus, pollutants emitted reach Delhi via air masses, deteriorating its air quality. Meteorological conditions influence pollutant concentrations during both seasons. Frequent dust storms in rabi, and Dusshera and Diwali firework celebrations in kharif season exacerbate air pollution. In rabi, PM 10 and PM 2.5 have a significant negative association with (relative humidity) RH and positive association with (air temperature) AT. High AT during pre-monsoon, accompanied by low RH, loosens up soil particles and they can easily disperse. Stronger winds in rabi season promote NO 2 and SO 2 dispersion. In kharif, lower AT, higher RH and slower winds exist. Both PM 10 and PM 2.5 have a negative association with AT and (wind speed) WS. With lower temperature and slower winds during winter, pollutants are trapped within the boundary layer and are unable to disperse. As expected, NO 2 has a significant negative association with AT in Haryana. However, in case of Delhi, the association is significant but positive, and could be due to the odd-even scheme imposed by the Delhi government. More research is needed to determine the health effects of Haryana's rabi CRB activities on Delhi.
Aerosol chemical composition over Istanbul
and were analysed for the main ions, trace metals, water-soluble organic carbon (WSOC), organic (OC) and elemental carbon (EC). PM 10 levels were found to be in good agreement with those measured by the Istanbul Municipality air quality network, indicating that the sampling site is representative of the Greater Istanbul Area. The main ions measured in the PM 10 samples were Na + , Ca 2+ and non-sea-salt sulphates (nss-SO 4 2−). On average, 31% of Ca 2+ was found to be associated with carbonates. Trace elements related to human activities (as Pb, V, Cd and Ni) obtained peak values during winter due to domestic heating, whereas natural origin elements like Al, Fe and Mn peaked during the spring period due to dust transport from Northern Africa. Organic carbon was found to be mostly primary and elemental carbon was strongly linked to fuel oil combustion and traffic. Both OC and EC concentrations increased during winter due to domestic heating, while the higher WSOC to OC ratio during summer can be mostly attributed to the presence of secondary, oxidised and more soluble organics. Factor analysis identified six components/sources for aerosol species in PM 10 , namely traffic/ industrial, crustal, sea-salt, fuel–oil combustion, secondary and ammonium sulfate.
Pathways for the oxidation of sarin in urban atmospheres
Environmental Science and Pollution Research, 1999
Los Alarnos Nntioiral Labornfoy is operated by the Utziversify of California for the United States Department of Energy under contract W-7405-ENG36. 1 An Afirmafive ActioiiEqiml Opportiiiiity Employer This report was prepared as an accoziizf of work sponsored hj an agency of the Uizited Stafes Government. Neither The Regenfs qfthe University qf Cizlifomia, the United Stafes Government nor any agency therec$ nor any of their employees, makes nny warranty, express or implied, or assumes any legal liability or respoizsibilityfor the acciiracy, completeness, or iisefiifizess ofany information, apparatus, product, or process disclosed, or represents that its rise would not infinge privately owned rights. Refeerice herein to nny spec@ commercial product, process, or setvice by trade name, tradeninrk, mnnzlfacturer, or otlimise, does not iiecessarily constitute or imply its endorsement, recommendation, or favmhig by The Regetits of the University of Califomin, the United States Government, or ally agency thereof. "lie views and opinions of authors expressed herein do not necessarily state or reflect those of The Regents of the University of Cal@rnin, the United States Govenznrent, or any agency thereof. Los Alamos Nationnl Laboratory strongly s q p r t s academic freedom and a researcher's right to piiblish; as an institzition, howeuer, the Laboratory does not endorse the viewpoint of n pziblicntion or guarantee its technical correctness. .
Journal of Geophysical Research, 2010
data set on the chemical composition of ambient aerosols collected from an urban location (Kanpur) in the Indo-Gangetic Plain (IGP) and suggests that the varying strength of the regional emission sources, boundary layer dynamics, and formation of secondary aerosols all contribute significantly to the temporal variability in the mass concentrations of elemental carbon (EC), organic carbon (OC), and water-soluble OC (WSOC). On average, carbonaceous aerosols contribute nearly one third of the PM 10 mass during winter, whereas their fractional mass is only ∼10% during summer. A three-to four-fold increase in the OC and K + concentrations during winter and a significant linear relation between them suggest biomass burning (wood fuel and agricultural waste) emission as a dominant source. The relatively high OC/EC ratio (average: 7.4 ± 3.5 for n = 66) also supports that emissions from biomass burning are overwhelming for the particulate OC in the IGP. The WSOC/OC ratios vary from 0.21 to 0.70 over the annual seasonal cycle with relatively high ratios in the summer, suggesting the significance of secondary organic aerosols. The long-range transport of mineral aerosols from Iran, Afghanistan, and the Thar Desert (western India) is pronounced during summer months. The temporal variability in the concentrations of selected inorganic constituents and neutralization of acidic species (SO 4 2− and NO 3 − ) by NH 4 + (dominant during winter) and Ca 2+ (in summer) reflect conspicuous changes in the source strength of anthropogenic emissions. Citation: Ram, K., M. M. Sarin, and S. N. Tripathi (2010), A 1 year record of carbonaceous aerosols from an urban site in the Indo-Gangetic Plain: Characterization, sources, and temporal variability,
Atmospheric Research, 2018
PM10 aerosol samples collected from a suburban site in Coimbatore during pre-monsoon, monsoon, post-monsoon and winter from 2014-16 showed a large variability from 7.6 to 89 µg m-3 with an annual average of 41 ± 21 µg m-3 (N=69). High abundance of PM10 and other components were recorded during winter and lowest during monsoon period. Total carbonaceous aerosols and water soluble ionic species contributed to 31% and 45% of PM10 mass respectively. SO4 2was the most abundant species (average ~ 9.8 ± 4.8 µg m-3) and constituted for 24% of total mass. Organic Carbon (OC) was the next most abundant species ranging from 1 to 16 µg m-3 with an average of 7 ± 3.6 µg m-3 accounting for 17% of PM10 mass concentration. POC (primary organic carbon) and SOC (secondary organic carbon) accounted for 56% and 44% of OC respectively. A major portion of OC (~ 60%) was found to be water soluble. The correlation between OC and EC (elemental carbon) was found to be higher for night-time compared to daytime suggesting their origin from common sources during night-time. K + was found to be strongly correlated with OC during night-time. WSOC showed good correlation with POC and K + which was high especially during night-time. WSON (water soluble organic nitrogen) accounted for 34% of water soluble total nitrogen (WSTN). HCO3exhibited significant positive correlation with Ca 2+ during daytime indicating their crustal origin. The observations suggest that the region is influenced by biomass burning sources, however during daytime , secondary production and terrestrial sources (due to high temperature and wind) significantly influence the atmospheric aerosols over this region.