scholarly journals Assessment of Particulate Air Pollution at Kalabagan and Shisumela Area Along the Mirpur Road, Dhaka

1970 ◽  
Vol 46 (3) ◽  
pp. 343-352
Author(s):  
BA Begum ◽  
M Kamal ◽  
A Salam ◽  
A Salam ◽  
MA Salam ◽  
...  

Characteristics of airborne particulate matter (PM2.5 and PM10) and black carbon (BC) concentrations have been studied at Kalabagan and Shishumela sites along Mirpur corridor in Dhaka city. These sites are the major road junction of Mirpur corridor and can represent urban background. Both PM2.5 and PM10 fractions were collected simultaneously from both sites by using Air Metrics samplers. The samplings were done for 7 days from the 19-25 January and 5 days from 27- 31 January 2009 at Kalabagan and Shisumela sites respectively. It was found that the ambient PM2.5 and PM10 concentrations were much higher than the daily Bangladesh National Ambient Air Quality Standard. From reconstructed mass (RCM) method, it was found that about 90% of PM2.5 mass comes from anthropogenic sources like motor vehicles, diesel powered generator and biomass burning sources. Since the samplings were carried out during the wintertime, the long-range transport is also expected to contribute to increase the fine PM mass. Key words: PM10; PM2.5; BC; RCM; long-range transport DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9041 BJSIR 2011; 46(3): 343-352

2015 ◽  
Vol 15 (8) ◽  
pp. 11409-11464 ◽  
Author(s):  
H. Pawar ◽  
S. Garg ◽  
V. Kumar ◽  
H. Sachan ◽  
R. Arya ◽  
...  

Abstract. Many sites in the densely populated Indo Gangetic Plain (IGP) frequently exceed the national ambient air quality standard (NAAQS) of 100 μg m−3 for 24 h average PM10 and 60 μg m−3 for 24 h average PM2.5 mass loadings, exposing residents to hazardous levels of PM throughout the year. We quantify the contribution of long range transport to elevated PM levels and the number of exceedance events through a back trajectory climatology analysis of air masses arriving at the IISER Mohali Atmospheric Chemistry facility (30.667° N, 76.729° E; 310 m a.m.s.l.) for the period August 2011–June 2013. Air masses arriving at the receptor site were classified into 6 clusters, which represent synoptic scale air mass transport patterns and the average PM mass loadings and number of exceedance events associated with each air mass type were quantified for each season. Long range transport from the west leads to significant enhancements in the average coarse mode PM mass loadings during all seasons. The contribution of long range transport from the west and south west (Source region: Arabia, Thar desert, Middle East and Afghanistan) to coarse mode PM varied between 9 and 57% of the total PM10−2.5 mass. Local pollution episodes (wind speed < 1 m s−1) contributed to enhanced coarse mode PM only during winter season. South easterly air masses (Source region: Eastern IGP) were associated with significantly lower coarse mode PM mass loadings during all seasons. For fine mode PM too, transport from the west usually leads to increased mass loadings during all seasons. Local pollution episodes contributed to enhanced PM2.5 mass loadings during winter and summer season. South easterly air masses were associated with significantly lower PM2.5 mass loadings during all seasons. Using simultaneously measured gas phase tracers we demonstrate that most PM2.5 originated from combustion sources. The fraction of days in each season during which the PM mass loadings exceeded the national ambient air quality standard was controlled by long range transport to a much lesser degree. For the local cluster, which represents regional air masses (Source region: NW-IGP), the fraction of days during which the national ambient air quality standard (NAAQS) of 60 μg m−3 for 24 h average PM2.5 was exceeded, varied between 22% of the days associated with this synoptic scale transport during monsoon season and 85% of the days associated with this synoptic scale transport during winter season; the fraction of days during which the national ambient air quality standard (NAAQS) of 100 μg m−3 for the 24 h average PM10 was exceeded, varied between 37% during monsoon season and 84% during winter season. Long range transport was responsible for both, bringing air masses with a significantly lower fraction of exceedance days from the Eastern IGP and air masses with a moderate increase in the fraction of exceedance days from the West (Source region: Arabia, Thar desert, Middle East and Afghanistan). In order to bring PM mass loadings in compliance with the national ambient air quality standard (NAAQS) and reduce the number of exceedance days, mitigation of regional pollution sources in the NW-IGP needs to be given highest priority.


2015 ◽  
Vol 15 (16) ◽  
pp. 9501-9520 ◽  
Author(s):  
H. Pawar ◽  
S. Garg ◽  
V. Kumar ◽  
H. Sachan ◽  
R. Arya ◽  
...  

Abstract. Many sites in the densely populated Indo-Gangetic Plain (IGP) frequently exceed the national ambient air quality standard (NAAQS) of 100 μg m−3 for 24 h average PM10 and 60 μg m−3 for 24 h average PM2.5 mass loadings, exposing residents to hazardous levels of particulate matter (PM) throughout the year. We quantify the contribution of long-range transport to elevated PM levels and the number of exceedance events through a back-trajectory climatology analysis of air masses arriving at the IISER Mohali Atmospheric Chemistry facility (30.667° N, 76.729° E; 310 m a.m.s.l.) for the period August 2011–June 2013. Air masses arriving at the receptor site were classified into six clusters, which represent synoptic-scale air-mass transport patterns. Long-range transport from the west leads to significant enhancements in the average fine- and coarse-mode PM mass loadings during all seasons. The contribution of long-range transport from the west and south-west (source regions: Arabia, Thar Desert, Middle East and Afghanistan) to coarse-mode PM varied between 9 and 57 % of the total PM10–2.5 mass. Local pollution episodes (wind speed < 1 m s−1) contributed to enhanced PM2.5 mass loadings during both the winter and summer seasons and to enhanced coarse-mode PM only during the winter season. South-easterly air masses (source region: eastern IGP) were associated with significantly lower fine- and coarse-mode PM mass loadings during all seasons. The fraction of days in each season during which the PM mass loadings exceeded the national ambient air quality standard was controlled by long-range transport to a much lesser degree. For the local cluster, which represents regional air masses (source region: NW-IGP), the fraction of days during which the national ambient air quality standard (NAAQS) of 60 μg m−3 for 24 h average PM2.5 was exceeded varied between 36 % of the days associated with this synoptic-scale transport during the monsoon, and 95 % during post-monsoon and winter seasons; the fraction of days during which the NAAQS of 100 μg m−3 for the 24 h average PM10 was exceeded, varied between 48 % during the monsoon and 98 % during the post-monsoon season. Long-range transport was responsible for both, bringing air masses with a significantly lower fraction of exceedance days from the eastern IGP and air masses with a moderate increase in the fraction of exceedance days from the west (source regions: Arabia, Thar Desert, Middle East and Afghanistan). In order to bring PM mass loadings into compliance with the NAAQS and to reduce the number of exceedance days, mitigation of regional combustion sources in the NW-IGP needs to be given highest priority.


2011 ◽  
Vol 11 (11) ◽  
pp. 30053-30089 ◽  
Author(s):  
X. W. Fu ◽  
X. Feng ◽  
P. Liang ◽  
H. Zhang ◽  
J. Ji ◽  
...  

Abstract. Measurements of speciated atmospheric mercury were conducted at a remote mountain-top station (WLG) at the edge of northeastern part of the Qinghai-Xizang Plateau, western China. Mean concentrations of total gaseous mercury (TGM), particulate mercury (PHg), and reactive gaseous mercury (RGM) during the whole sampling campaign were 1.98 &amp;pm; 0.98 ng m−3, 19.4 &amp;pm; 18.1 pg m−3, and 7.4 &amp;pm; 4.8 pg m−3, respectively. Levels of speciated Hg at WLG were slightly higher than those reported from remote areas of North America and Europe. Both regional emissions and long-rang transport played a remarkable role in the distribution of TGM and PHg in ambient air at WLG, whereas RGM showed major links to the regional sources, likely as well as the in-situ productions by photochemical processes. Regional sources for speciated Hg were mostly located to the east of WLG, which is the most developed areas of Qinghai province and accounted for most of the province's anthropogenic Hg emissions. Potential source contribution function (PSCF) results showed a strong impact of long-range transport from eastern Gansu, western Ningxia and Shanxi Province, with good accordance with locations of urban areas and industrial centers. Moreover, we found that northern India was also an important source region of WLG during the sampling campaign, and this is the first time of direct evidence of long-range transport of atmospheric Hg from India to northeastern Tibetan Plateau. Seasonal and diurnal variations of TGM were in contrast with most of the previous studies in China, with relatively higher levels in warm seasons and night, respectively. The temporal trend of TGM also highlighted the impact of long-range transport on the distribution of TGM in ambient air at WLG.


2008 ◽  
Vol 8 (20) ◽  
pp. 6281-6295 ◽  
Author(s):  
S. Saarikoski ◽  
H. Timonen ◽  
K. Saarnio ◽  
M. Aurela ◽  
L. Järvi ◽  
...  

Abstract. A major fraction of fine particle matter consists of organic carbon (OC) but its origin is still inadequately known. In this study the sources of OC were investigated in the northern European urban environment in Helsinki, Finland. Measurements were carried out over one year and they included both filter (PM1) and online methods. From the filter samples OC, elemental carbon (EC), water-soluble OC (WSOC), levoglucosan and major ions were analyzed. Filter data together with the concentrations of inorganic gases were analyzed by Positive matrix factorization (PMF) in order to find the sources of OC (and WSOC) on an annual as well as on a seasonal basis. In order to study the diurnal variation of sources, OC and EC were measured by a semicontinuous OC/EC analyzer and major ions were determined by a Particle-into-Liquid Sampler coupled to ion chromatographs. According to PMF, OC concentrations were impacted by four sources: biomass combustion, traffic, long-range transport and secondary production. On an annual basis the OC concentration was dominated by secondary organic aerosol (SOA). Its contribution to OC was as high as 64% in summer, which besides anthropogenic sources may also result from the large biogenic volatile organic carbon (VOC) emissions in the boreal region. In winter biomass combustion constituted the largest fraction in OC due to domestic wood combustion for heating purposes. Traffic contributed to OC from 15 to 27%. Regarding the diurnal variation, the contribution from traffic was higher from 08:00 to 18:00 on weekdays than on weekends. The contribution from long-range transport to OC was 24% on average. All four sources also influenced the WSOC concentrations, however, the contribution of SOA was significantly larger for WSOC than OC.


2018 ◽  
Author(s):  
Cyrille Flamant ◽  
Adrien Deroubaix ◽  
Patrick Chazette ◽  
Joel Brito ◽  
Marco Gaetani ◽  
...  

Abstract. The complex vertical distribution of aerosols over coastal southern West Africa (SWA) is investigated using airborne observations and numerical simulations. Observations were gathered on 2 July 2016 offshore of Ghana and Togo, during the field phase of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa project. The aerosol loading in the lower troposphere includes emissions from coastal cities (Accra, Lomé, Cotonou and Lagos) as well as biomass burning aerosol and dust associated with long-range transport from Central Africa and the Sahara, respectively. Our results indicate that the aerosol distribution is impacted by subsidence associated with zonal and meridional regional scale overturning circulations associated with the land-sea surface temperature contrast and orography over Ghana and Togo. Numerical tracer release experiments highlight the dominance of aged emissions from Accra on the observed pollution plume loadings over the ocean. The contribution of aged emission from Lomé and Cotonou is also evident above the marine boundary layer. Lagos emissions do not play a role for the area west of Cotonou. The tracer plume does not extend very far south over the ocean (i.e. less than 100 km from Accra), mostly because emissions are transported northeastward near the surface over land and westward above the marine atmospheric boundary layer. The latter is possible due to interactions between the monsoon flow, complex terrain and land-sea breeze systems, which support the vertical mixing of the urban pollution. This work sheds light on the complex – and to date undocumented – mechanisms by which coastal shallow circulations distribute atmospheric pollutants over the densely populated SWA region.


2016 ◽  
Author(s):  
Yong-Seok Seo ◽  
Seung-Pyo Jeong ◽  
Thomas M. Holsen ◽  
Young-Ji Han ◽  
Eunhwa Choi ◽  
...  

Abstract. Total gaseous mercury (TGM) concentrations were measured every 5 min in Pohang, Gyeongsangbuk-do, Korea during summer (17 August–23 August 2012), fall (9 October–17 October 2012), winter (22 January–29 January 2013), and spring (26 March–3 April 2013) to: 1) characterize the hourly and seasonal variations of atmospheric TGM concentrations, 2) identify the relationships between TGM and co-pollutants, and 3) identify likely source directions and locations of TGM using conditional probability function (CPF), conditional bivariate probability function (CBPF) and total potential source contribution function (TPSCF). The TGM concentration was statistically significantly highest in fall (6.7 ± 6.4 ng m−3), followed by spring (4.8 ± 4.0 ng m−3), winter (4.5 ± 3.2 ng m−3) and summer (3.8 ± 3.9 ng m−3). There was a statistically significant negative correlation between the TGM concentration and ambient air temperature (r = −0.08) (p < 0.05). Although the daytime temperature (14.7 ± 10.0 °C) was statistically significantly higher than that in the nighttime (13.0 ± 9.8 °C) (p < 0.05), the daytime TGM concentration (5.3 ± 4.7 ng m−3) was statistically significantly higher than those in the night time (4.7 ± 4.7 ng m−3) (p < 0.01), possibly due to local emissions related to industrial activities and activation of local surface emission sources. The observed ΔTGM/ΔCO was significantly lower than that of Asian long-range transport, but similar to that of local sources in Korea and in US industrial events suggesting that local sources are more important than that of long-range transport. CPF, CBPF and TPSCF indicated that the main sources of TGM were iron and manufacturing facilities, the hazardous waste incinerators and the coastal areas.


2012 ◽  
Vol 12 (11) ◽  
pp. 29391-29442 ◽  
Author(s):  
M. Bressi ◽  
J. Sciare ◽  
V. Ghersi ◽  
N. Bonnaire ◽  
J. B. Nicolas ◽  
...  

Abstract. Studies describing the chemical composition of fine aerosol (PM2.5) in urban areas are often conducted during few weeks only, and at one sole site, giving thus a narrow view of their temporal and spatial characteristics. This paper presents a one-year (11 September 2009–10 September 2010) survey of the daily chemical composition of PM2.5 in the region of Paris, which is the second most populated "Larger Urban Zone" in Europe. Five sampling sites representative of suburban (SUB), urban (URB), northeast (NER), northwest (NWR) and south (SOR) rural backgrounds were implemented. The major chemical components of PM2.5 were determined including elemental carbon (EC), organic carbon (OC), and the major ions. OC was converted to organic matter (OM) using the chemical mass closure methodology, which leads to conversion factors of 1.95 for the SUB and URB sites, and 2.05 for the three rural ones. On average, gravimetrically determined PM2.5 annual mass concentrations are 15.2, 14.8, 12.6, 11.7 and 10.8 μg m−3 for SUB, URB, NER, NWR and SOR sites, respectively. The chemical composition of fine aerosol is very homogeneous at the five sites and is composed of OM (38–47%), nitrate (17–22%), non-sea-salt sulfate (13–16%), ammonium (10–12%), EC (4–10%), mineral dust (2–5%) and sea salt (3–4%). This chemical composition is in agreement with those reported in the literature for most European environments. On the annual scale, Paris (URB and SUB sites) exhibits its highest PM2.5 concentrations during late autumn, winter and early spring (higher than 15 μg m−3 on average, from December to April), intermediates during late spring and early autumn (between 10 and 15 μg m−3 during May, June, September, October, and November) and the lowest during summer (below 10 μg m−3 during July and August). PM levels are mostly homogeneous at the regional scale, on the whole duration of the project (e.g. for URB plotted against NER sites: slope = 1.06, r2 = 0.84, n = 330), suggesting the importance of mid- or long-range transport, and regional instead of local scale phenomena. During this one-year project, two third of the days exceeding the PM2.5 2015 EU annual limit value of 25 μg m−3 were due to continental import from countries located northeast, east of France. This result questions the efficiency of local, regional and even national abatement strategies during pollution episodes, pointing the need for a wider collaborative work with the neighbourhood countries on these topics. Nevertheless, emissions of local anthropogenic sources lead to higher levels at the URB and SUB sites compared to the others (e.g. 26% higher on average at the URB than at the NWR site for PM2.5, during the whole campaign), which can even be emphasised by specific meteorological conditions such as low boundary layer heights. OM and secondary inorganic species (nitrate, non-sea-salt sulfate and ammonium, noted SIA) are mainly imported by mid- or long-range transport (e.g. for NWR plotted against URB sites: slope = 0.79, r2 = 0.72, n = 335 for OM, and slope = 0.91, r2 = 0.89, n = 335 for SIA) whereas EC is primarily locally emitted (e.g. for SOR plotted against URB sites: slope = 0.27; r2 = 0.03; n = 335). This database will serve deepest investigations of carbonaceous aerosols, metals as well as the main sources and geographical origins of PM in the region of Paris.


2015 ◽  
Vol 15 (2) ◽  
pp. 1129-1145 ◽  
Author(s):  
A. Ripoll ◽  
M. C. Minguillón ◽  
J. Pey ◽  
N. Pérez ◽  
X. Querol ◽  
...  

Abstract. The complete chemical composition of atmospheric particulate matter (PM1 and PM10) from a continental (Montsec, MSC, 1570 m a.s.l.) and a regional (Montseny, MSY, 720 m a.s.l) background site in the western Mediterranean Basin (WMB) were jointly studied for the first time over a relatively long-term period (January 2010–March 2013). Differences in average PMX concentration and composition between both sites were attributed to distance to anthropogenic sources, altitude, and different influence of atmospheric episodes. All these factors result in a continental-to-regional background increase of 4.0 μg m−3 for PM10 and 1.1 μg m−3 for PM1 in the WMB. This increase is mainly constituted by organic matter, sulfate, nitrate, and sea salt. However, higher mineral matter concentrations were measured at the continental background site owing to the higher influence of long-range transport of dust and dust resuspension. Seasonal variations of aerosol chemical components were attributed to evolution of the planetary boundary layer (PBL) height throughout the year, variations in the air mass origin, and differences in meteorology. During warmer months, weak pressure gradients and elevated insolation generate recirculation of air masses and enhance the development of the PBL, causing the aging of aerosols and incrementing pollutant concentrations over a large area in the WMB, including the continental background. This is reflected in a more similar relative composition and absolute concentrations of continental and regional background aerosols. Nevertheless, during colder months the thermal inversions and the lower vertical development of the PBL leave MSC in the free troposphere most of the time, whereas MSY is more influenced by regional pollutants accumulated under winter anticyclonic conditions. This results in much lower concentrations of PMX components at the continental background site with respect to those at the regional background site. The influence of certain atmospheric episodes caused different impacts at regional and continental scales. When long-range transport from central and eastern Europe and from north Africa occurs, the continental background site is frequently more influenced, thus indicating a preferential transport of pollutants at high altitude layers. Conversely, the regional background site was more influenced by regional processes. Continental and regional aerosol chemical composition from the WMB revealed (a) high relevance of African dust transport and regional dust resuspension; (b) low biomass burning contribution; (c) high organic matter contribution; (d) low summer nitrate concentrations; and (e) high aerosol homogenization in summer.


2017 ◽  
Vol 56 ◽  
pp. 214-229 ◽  
Author(s):  
Deping Li ◽  
Jianguo Liu ◽  
Jiaoshi Zhang ◽  
Huaqiao Gui ◽  
Peng Du ◽  
...  

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