Status of Air Pollutants after Implementation of CNG in Delhi

Saxena, Pallavi; Bhardwaj, Rashmi; Chirashree, Ghosh

doi:10.12944/cwe.7.1.17

Cited by 19 publications

(5 citation statements)

References 8 publications

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“…The present observations show a rise in NO 2 , RSPM and SPM levels whereas a decreasing trend is observed in SO 2 . A decreasing trend in SO 2 may be attributed to various interventions that have taken place over the last decade such as shutting down of hazardous industries, reduction of sulphur content in petrol and diesel, use of cleaner fuel for transport (such as CNG) and domestic (such as LPG) purposes (Saxena et al 2012;Gurjar et al 2016). However, at the same time the number of vehicles has increased exponentially which is one of the major sources of NO 2 and other pollutants.…”

Section: Monthly and Seasonal Variation Of Air Pollutantsmentioning

confidence: 99%

Long-term (2005–2012) measurements of near-surface air pollutants at an urban location in the Indo-Gangetic Basin

et al. 2019

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Simultaneous long-term measurements of near-surface air pollutants at an urban station, New Delhi, were studied during 2005-2012 to understand their distribution on different temporal scales. The annual mean mass concentrations of nitrogen dioxide (NO 2), sulphur dioxide (SO 2), particulate matter less than 10 µm (PM 10) and suspended particulate matter (SPM) were found to be 62.0 ± 27.6, 12.5 ± 8.2, 253.7 ± 134 and 529.2 ± 213.1 µg/m 3 , respectively. The 24-hr mean mass concentrations of NO 2 , PM 10 and SPM were exceeded on ∼27%, 87% and 99% days that of total available measurement days to their respective National Ambient Air Quality Standard (NAAQS) level. However, it never exceeded for SO 2 , which could be attributed to reduction of sulphur in diesel, use of cleaner fuels such as compressed natural gas, LPG, etc. The mean mass concentrations of measured air pollutants were found to be the highest during the winter/post-monsoon seasons, which are of concern for both climate and human health. The annual mean mass concentrations of NO 2 , PM 10 and SPM showed an increasing trend while SO 2 appears to be decreasing since 2008. Air mass cluster analysis showed that north-northwest trajectories accounted for the highest mass concentrations of air pollutants (more prominent in the winter/post-monsoon season); however, the lowest were associated with the southeast trajectory cluster.

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Section: Monthly and Seasonal Variation Of Air Pollutantsmentioning

confidence: 99%

Long-term (2005–2012) measurements of near-surface air pollutants at an urban location in the Indo-Gangetic Basin

et al. 2019

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“…These measures are shutting down of hazardous industries, banned the use of diesel vehicles (older than 10 years) within the city, use of low sulphur content of the petrol and diesel fuels, implementation of compressed natural gas (CNG) vehicles, use of cleaner fuel for domestic purposes (e.g. liquefied petroleum gas (LPG)/ piped natural gas (PNG)) and very recently traffic intervention odd-even policy ( Goyal and Sidhartha, 2003 ; Narain and Krupnick, 2007 ; Saxena et al, 2012 ; CPCB, 2016 ; Chowdhury et al, 2017 ; Khanna and Sharma, 2020 ). Despite all the above efforts, the concentration of PM 2.5 and other pollutants remain at their alarming levels in Delhi and its surrounding regions, which led to major health concerns in the recent times ( Maji et al, 2015 ; Chowdhury and Dey, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Srivastava¹,

Bhoyar

Kanawade

et al. 2021

Urban Climate

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The enforced lockdown amid COVID-19 pandemic eased anthropogenic activities across India. The satellite-derived aerosol optical depth (AOD) and absorption AOD showed a significant reduction of ~30% over the Indo-Gangetic Basin (IGB) in north India during the lockdown period in 2020 with respect to the previous year 2019, when no such lockdown was in effect. Further, near-surface air pollutants were investigated at an urban megacity Delhi during 01 March to 31 May 2020. Except O 3 , a drastic reduction in PM 10 , PM 2.5 , NO, NO 2 and CO concentrations were observed by ~58%, 47%, 76%, 68% and 58%, respectively during the lockdown period of 2020 as compared to 2019. While, O 3 was low in the initial phase and gradually increased with progression of lockdown phases, the mean O 3 during the entire lockdown period was nearly similar in both the years. Though, all the measured pollutants showed significant reduction during the entire lockdown, a phase-wise enhancement, associated with the conditional relaxations was observed in their concentrations. Thus, the present results may help, not only to assess the impact of outbreak on air quality, but also in designing the mitigation policies in urban megacities in more efficient ways to combat the air pollution problems.

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“…Air quality in selected sampling sites A higher concentration of CO, SO 2 , NO 2 and VOC values were recorded at the arterial road sites in comparison to the control. It has been reported by Saxena et al (2012) that in the urban areas, traffic flow is among the foremost emission sources. Thus, the three arterial roads could had higher pollutant vehicular air pollutant levels than the control site.…”

Section: Discussionmentioning

confidence: 99%

“…Similar observation was reported in Gladiolus gandavensis (Swami et al 2004). Low pH values is an indication of sensitivity of the plant species to air pollutants, while high pH could provide tolerance to pollutants (Govindaraju et al 2012;Saxena et al 2012). Plants exposed to air pollutants (specifically, SO 2 ) generate substantial H + to react with SO 2 , which enters through the stomata, resulting H 2 SO 4 and lowering of leaf pH (Zhen 2000).…”

Section: Discussionmentioning

confidence: 99%

Roadside air pollution in a tropical city: physiological and biochemical response from trees

2019

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Background:The economic growth and social interaction of many developing countries have been enhanced by vehicular transportation. However, this has come with considerable environmental cost. The vehicular emissions of gases such as carbon monoxide (CO), sulphur dioxide (SO 2 ), nitrogen oxide (NOx) and volatile organic compounds (VOC's) among others are associated with vehicular transportation. The resultant effect can lead to respiratory infections in humans, as well as growth inhibition and death of animals and plants. An investigation was conducted to evaluate the impact of vehicular air pollutants on some selected roadside tree species in the Kumasi Metropolis, Ghana. Ficus platyphylla, Mangifera indica, Polyalthia longifolia and Terminalia catappa, which were abundant and well distributed along the road sides, were selected for the study. Three arterial roads in the Kumasi Metropolis, namely Accra Road (Arterial I), Offinso Road (Arterial II) and Mampong Road (Arterial III), were considered as different traffic volumes experimental sites. The KNUST campus was selected as a control site. Diurnal analysis of CO, NO 2 , SO 2 and VOC was monitored in the sample sites. Three replicates of each tree species were defined at a distance 10 m away from the edge of the road. Physiologically active leaves (20 to 25) from each tree species replicate were harvested for physiological and biochemical determination. Results:The ambient air quality data showed higher levels at the arterial road sites, which were severely polluted based on air quality index. The biochemical studies revealed reductions in leaf total chlorophyll and leaf extract pH whilst leaf ascorbic acid and relative water contents increased at the arterial road sites.Conclusion: It was found that the plants' tolerant response level to vehicular air pollution was in the order T. catappa > F. platyphylla > M. indica and P. longifolia. Based on anticipated performance index, it was revealed that M. indica, F. platyphylla and T. catappa might be performing some level of air cleaning functions along the arterial roads. Whilst P. longifolia was poor and unsuitable as a pollution sink.

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Status of Air Pollutants after Implementation of CNG in Delhi

Cited by 19 publications

References 8 publications

Long-term (2005–2012) measurements of near-surface air pollutants at an urban location in the Indo-Gangetic Basin

Long-term (2005–2012) measurements of near-surface air pollutants at an urban location in the Indo-Gangetic Basin

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Roadside air pollution in a tropical city: physiological and biochemical response from trees

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