Assessment of air pollution disparities and allied climatic variability across the SAARC nations during the past quarter century
(2026) In Frontiers in Environmental Science 14.- Abstract
This study presents a comprehensive 25-year chronology of air pollution and climatic variable disparity across seven SAARC nations—Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka—emphasizing the region’s developing burdens of fine PM2.5 and SO2 from 2000 to 2024. MODIS and MERRA-2 data are used for a regional-scale analysis of seasonal, annual, and inter-annual variations in PM2.5 and SO2 concentrations. Spatially averaged metrics reveal marked disparities among SAARC countries, with Bangladesh, India, and Pakistan emerging as severe hot spots of PM2.5 pollution. Seasonal cycles demonstrate that winter months commonly... (More)
This study presents a comprehensive 25-year chronology of air pollution and climatic variable disparity across seven SAARC nations—Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka—emphasizing the region’s developing burdens of fine PM2.5 and SO2 from 2000 to 2024. MODIS and MERRA-2 data are used for a regional-scale analysis of seasonal, annual, and inter-annual variations in PM2.5 and SO2 concentrations. Spatially averaged metrics reveal marked disparities among SAARC countries, with Bangladesh, India, and Pakistan emerging as severe hot spots of PM2.5 pollution. Seasonal cycles demonstrate that winter months commonly experience peak pollutant accumulation, attributed to stable atmospheric boundary layers and reduced vertical mixing. Conversely, monsoon periods generally result in lower PM2.5 and SO2 concentrations due to enhanced wet scavenging and increased rainfall. PM2.5 values range as high as 100 µgm−3 in Bangladesh and often exceed 55 µgm−3 seasonally in India, while Sri Lanka and Bhutan maintain comparatively lower baseline levels, although with episodic cross-boundary pollution spikes. Simultaneously, climatic variables such as temperature, wind speed, precipitation, and planetary boundary level height were analyzed for air pollution. This study shows that policy interventions, although increasing, remain insufficiently robust to counteract the region’s escalating pollution problem as continued industrialization, population growth, and infrastructure expansion offset regulatory progress. The analysis provides an understanding of the spatio-temporal evolution of PM2.5 and SO2 in South Asia, highlighting the urgent need for regionally coordinated, multi-sector emission control strategies. Bangladesh stands out as the most severely impacted, followed by India. The overall air quality in the SAARC nations has been deteriorating, notably over the most recent 4-year period.
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- author
- Bhatla, R. ; Kumar, Pradeep ; Dash, Yajnaseni ; Bissessur, Needhish ; Lodh, Abhishek LU ; Singh, Vivek and Awasthi, Amit
- organization
- publishing date
- 2026-05-13
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- climate variables, MERRA-2, MODIS, PM2.5, SO, South Asian Association for Regional Cooperation
- in
- Frontiers in Environmental Science
- volume
- 14
- article number
- 1803958
- publisher
- Frontiers Media S. A.
- external identifiers
-
- scopus:105040963525
- ISSN
- 2296-665X
- DOI
- 10.3389/fenvs.2026.1803958
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: Copyright © 2026 Bhatla, Kumar, Dash, Bissessur, Lodh, Singh and Awasthi.
- id
- fd1839be-79c5-4490-8d6a-7d94f4713f30
- date added to LUP
- 2026-08-25 14:33:18
- date last changed
- 2026-08-25 14:37:53
@article{fd1839be-79c5-4490-8d6a-7d94f4713f30,
abstract = {{<p>This study presents a comprehensive 25-year chronology of air pollution and climatic variable disparity across seven SAARC nations—Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka—emphasizing the region’s developing burdens of fine PM<sub>2</sub>.<sub>5</sub> and SO<sub>2</sub> from 2000 to 2024. MODIS and MERRA-2 data are used for a regional-scale analysis of seasonal, annual, and inter-annual variations in PM<sub>2</sub>.<sub>5</sub> and SO<sub>2</sub> concentrations. Spatially averaged metrics reveal marked disparities among SAARC countries, with Bangladesh, India, and Pakistan emerging as severe hot spots of PM<sub>2</sub>.<sub>5</sub> pollution. Seasonal cycles demonstrate that winter months commonly experience peak pollutant accumulation, attributed to stable atmospheric boundary layers and reduced vertical mixing. Conversely, monsoon periods generally result in lower PM<sub>2</sub>.<sub>5</sub> and SO<sub>2</sub> concentrations due to enhanced wet scavenging and increased rainfall. PM<sub>2</sub>.<sub>5</sub> values range as high as 100 µgm<sup>−3</sup> in Bangladesh and often exceed 55 µgm<sup>−3</sup> seasonally in India, while Sri Lanka and Bhutan maintain comparatively lower baseline levels, although with episodic cross-boundary pollution spikes. Simultaneously, climatic variables such as temperature, wind speed, precipitation, and planetary boundary level height were analyzed for air pollution. This study shows that policy interventions, although increasing, remain insufficiently robust to counteract the region’s escalating pollution problem as continued industrialization, population growth, and infrastructure expansion offset regulatory progress. The analysis provides an understanding of the spatio-temporal evolution of PM<sub>2</sub>.<sub>5</sub> and SO<sub>2</sub> in South Asia, highlighting the urgent need for regionally coordinated, multi-sector emission control strategies. Bangladesh stands out as the most severely impacted, followed by India. The overall air quality in the SAARC nations has been deteriorating, notably over the most recent 4-year period.</p>}},
author = {{Bhatla, R. and Kumar, Pradeep and Dash, Yajnaseni and Bissessur, Needhish and Lodh, Abhishek and Singh, Vivek and Awasthi, Amit}},
issn = {{2296-665X}},
keywords = {{climate variables; MERRA-2; MODIS; PM2.5; SO; South Asian Association for Regional Cooperation}},
language = {{eng}},
month = {{05}},
publisher = {{Frontiers Media S. A.}},
series = {{Frontiers in Environmental Science}},
title = {{Assessment of air pollution disparities and allied climatic variability across the SAARC nations during the past quarter century}},
url = {{http://dx.doi.org/10.3389/fenvs.2026.1803958}},
doi = {{10.3389/fenvs.2026.1803958}},
volume = {{14}},
year = {{2026}},
}