Gaseous and aerosol pollutants during fog and clear episodes in South Asian urban atmosphere

Biswas, Karabi Farhana; Ghauri, Badar; Husain, Liaquat

doi:10.1016/j.atmosenv.2008.04.056

Cited by 115 publications

(66 citation statements)

References 38 publications

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“…The average concentration of SO 2− 4 in PM 2.5 was higher than that at rural sites in the NCP (Meng et al, 2011) and YRD (Meng et al, 2014) in China, but was lower than that observed at rural sites in Guangzhou (Hu et al, 2008) in China as well as urban sites in India (Behera and Sharma, 2010) and Egypt (Hassan et al, 2013). The average concentration of NO − 3 in PM 2.5 was higher than that observed at the rural sites in the YRD and Guangzhou (Hu et al, 2008) in China and lower than that at urban sites in India (Behera and Sharma, 2010) and Pakistan (Biswas et al, 2008). The elevated NH 3 and NH + 4 in PM 2.5 concentrations at the NCP rural site demonstrate severe ammonia and fine particulate ammonium pollution in this area.…”

Section: Overview Of Concentration Levels Of Measured Speciesmentioning

confidence: 60%

“…As listed in Table 1, the concentration of NH 3 at the NCP rural site was lower than that reported at Asian and African urban sites such as Lahore (Pakistan; Biswas et al, 2008), Colonelganj (India; Behera and Sharma, 2010), and Cairo (Egypt; Hassan et al, 2013) but higher than those from other areas in China, Europe, and North America (Plessow et al, 2005;Yao et al, 2006;Lin et al, 2006;Walker et al, 2006;Hu et al, 2008;Meng et al, 2011Meng et al, , 2014Shen et al, 2011;Schaap et al, 2011;Makkonen et al, 2012;Behera et al, 2013;Gong et al, 2013;Li et al, 2014). For example, the NH 3 at the NCP rural site was higher than that found at the Shangdianzi regional background station in the NCP (Meng et al, 2011), Lin'an regional background station in the Yangtze River Delta (YRD) in eastern China (Meng et al, 2014), and the rural site in Beijing .…”

Section: Overview Of Concentration Levels Of Measured Speciesmentioning

confidence: 89%

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Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

et al. 2018

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Abstract. The real-time measurements of NH 3 and trace gases were conducted, in conjunction with semi-continuous measurements of water-soluble ions in PM 2.5 at a rural site in the North China Plain (NCP) from May to September 2013 in order to better understand chemical characteristics of ammonia and the impact of secondary ammonium aerosols on formation in the NCP. Extremely high NH 3 and NH + 4 concentrations were observed after a precipitation event within 7-10 days following urea application. Elevated NH 3 levels coincided with elevated NH + 4 , indicating that NH 3 likely influenced particulate ammonium mass. For the sampling period, the average conversion / oxidation ratios for NH + 4 (NHR), SO 2− 4 (SOR), and NO − 3 (NOR) were estimated to be 0.30, 0.64, and 0.24, respectively. The increased NH 3 concentrations, mainly from agricultural activities and regional transport, coincided with the prevailing meteorological conditions. The high NH 3 level with NHR of about 0.30 indicates that the emission of NH 3 in the NCP is much higher than needed for aerosol acid neutralisation, and NH 3 plays an important role in the formation of secondary aerosols as a key neutraliser. The hourly data obtained were used to investigate gas-aerosol partitioning characteristics using the thermody-

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Section: Overview Of Concentration Levels Of Measured Speciesmentioning

confidence: 60%

Section: Overview Of Concentration Levels Of Measured Speciesmentioning

confidence: 89%

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

et al. 2018

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“…It should be noted that due to high temperatures and stable atmospheric conditions, several days with relatively high NH 3 levels were recorded in our observation, consequently leading to a relatively large mean NH 3 concentration. The NH 3 level in Beijing was lower compared to the measurements in some other cities around the world; for example, in Kaohsiung, Taiwan (31.5 ± 16.1 µg m -3 , winter 2006, Tsai et al, 2014);Kanpur, India (26.4 ± 5.8 µg m -3 , winter 2007, Behera andSharma, 2010); and Lahore, Pakistan (50.1 ± 16.9 µg m -3 , winter 2005, Biswas et al, 2008). However, in Beijing, the NH 3 level was still higher than those observed in some other cities of China including Shanghai (6.6 µg m -3 , autumn 2012, Shi et al, 2014) Hu et al, 2008).…”

Section: Nh 3 Concentration and Its Temporal Variationmentioning

confidence: 99%

Variation of Urban Atmospheric Ammonia Pollution and its Relation with PM2.5 Chemical Property in Winter of Beijing, China

Zhao

Wang

Tan

et al. 2016

Aerosol Air Qual. Res.

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To understand the air pollution problem in megacities such as Beijing, field measurement investigating the variation of NH 3 and its association with PM 2.5 chemical property was conducted from 25 November to 24 December 2013. The results indicated that the daily concentration of wintertime NH 3 tended to be high on the days with relatively high temperatures and low wind speeds. Affected by the synoptic condition, NH 3 concentration showed a bimodal diurnal variation pattern, which tended to peak at around 09:00 and 22:00 of the day. As the sole precursor for NH 4 + , NH 3 exerted a significant impact on the ion chemistry of PM 2.5 through enhancing the nighttime NH 4 Cl formation and promoting both homogeneous and heterogeneous formation of NO 3 -. During heavy pollution episodes with PM 2.5 concentrations over 200 µg m -3 , the NH 3 levels and NH 4 + /NH 3 ratios grew simultaneously with the increase of PM 2.5 levels, indicating that NH 3 is one of the key reasons for heavy pollution events. Revealed by the features of measured ionic species in PM 2.5 , in conjunction with the acidity analysis using thermodynamic model, our results suggested that NH 3 was frequently sufficient in wintertime atmosphere of urban Beijing and the fine particulates were neutralized nearly fully by NH 3 .

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“…11 The major emission sources in Karachi and Lahore, the two biggest cities of Pakistan, are vehicles, industries and fossil fuel based thermal power plants. 12,13 In order to monitor air quality in the country, Pakistan Space and Upper Atmosphere Research Commission (SUPARCO) carried out a number of short term winter studies in Lahore over the years 1998-99, 14 17 In these studies, exceptionally high SO 4 2-concentrations were reported during the foggy days. SO 4 2-/Se tracer technique was applied to quantify the in-cloud oxidation of sulfur dioxide.…”

Section: Introductionmentioning

confidence: 99%

Particulate matter (PM2.5) concentration and source apportionment in lahore

Lodhi¹,

Ghauri²,

Khan³

et al. 2009

J. Braz. Chem. Soc.

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Neste trabalho foram estudadas as concentrações das PM 2.5 (partículas com diâmetro aerodinâmico de 2,5 µm ou menos) e das fontes de incremento das PM 2.5 , monitoradas numa área urbana residencial de Lahore, Pasquitão. Amostras de PM 2.5 em aerosol foram coletadas 2 dias por semana, num inetravlo de 12 h por dia, nas estações seca e húmida, usando um filtro de papel Zefluor TM contendo um amostrador de ar ambiente termo-elétrico (Thermo-Electron Corporation Reference Ambient Air Sampler, RAAS ) durante o inverno, os quais aumentam a concentração total de PM 2.5 quando, relativamente, menos dispersão aérea existe. As partículas de sulfato também aumentam a formação de neblina/nevoeiro em condições calmaria e humidade, reduzindo a visbilidade e aumentando a incidência de doenças respiratórias na cidade ao longo do ano.The work reported in this paper was carried out to study the trends of PM 2.5 (particles with an aerodynamic diameter of 2.5 µm or less) concentrations and source apportionment of PM 2.5 monitored at an urban residential site in Lahore, Pakistan. PM 2.5 aerosol samples were collected for 2 days in a week at 12 h interval in a day, both in dry and wet seasons, on Zefluor TM filter papers using Thermo-Electron Corporation Reference Ambient Air Sampler (RAAS). Total 310 samples were collected during the period under study, i.e., from November 2005 to December 2007. High PM 2.5 loads were observed in winter, which were approximately 4 times greater than those observed in the summer, spring, fall and monsoon seasons in the yearlong measurements. Source apportionment was performed on short duration analysis results of November 2005 to March 2006 using Positive Matrix Factorization (PMF) model. The results derived from PMF model indicated that the major contributors to PM 2.5 in Lahore are: soil/road dust, industrial emissions, vehicular emissions and secondary aerosols. It is, therefore, concluded that in addition to local vehicular and industrial emissions, the city is also affected from trans-boundary air pollutants particularly due to secondary aerosols (especially SO 4 2-) during winter which increase PM 2.5 concentrations manifold when relatively less mixing height exists. The sulfate particles also facilitate in haze/fog formation during calm highly humid conditions, thus reduce visibility and increase the incidents of respiratory diseases encountered in the city every year.

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Gaseous and aerosol pollutants during fog and clear episodes in South Asian urban atmosphere

Cited by 115 publications

References 38 publications

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

Variation of Urban Atmospheric Ammonia Pollution and its Relation with PM2.5 Chemical Property in Winter of Beijing, China

Particulate matter (PM2.5) concentration and source apportionment in lahore

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