State of gaseous air pollutants and resulting health effects in Karachi, Pakistan

Omosehin D Moyebi; Fatim Sannoh; Zafar Fatmi; Azhar Siddique; Kamran Khan; Jahan Zeb; Mirza M Hussain; David O Carpenter; Haider A Khwaja

doi:10.1007/s10661-022-10787-1

State of gaseous air pollutants and resulting health effects in Karachi, Pakistan

Environ Monit Assess. 2023 Jan 5;195(2):266. doi: 10.1007/s10661-022-10787-1.

Authors

Omosehin D Moyebi^{1

2}, Fatim Sannoh^{1

2}, Zafar Fatmi³, Azhar Siddique⁴, Kamran Khan⁵, Jahan Zeb⁶, Mirza M Hussain^{1

2}, David O Carpenter^{1

7}, Haider A Khwaja^{8

9}

Affiliations

¹ Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY, 12201-0509, USA.
² Wadsworth Center, New York State Department of Health, Albany, NY, USA.
³ Department of Community Health Sciences, The Aga Khan University, Karachi, Pakistan.
⁴ Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Doha, 34110, Qatar.
⁵ Chemistry Department, University of Karachi, Karachi, Pakistan.
⁶ Department of Environmental and Health Research, The Custodian of the Two Holy Mosques Institute for Hajj and Umrah Research, Umm Al Qura University, Makkah, Saudi Arabia.
⁷ Institute for the Health and the Environment, University at Albany, Albany, NY, USA.
⁸ Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY, 12201-0509, USA. hkhwaja@albany.edu.
⁹ Wadsworth Center, New York State Department of Health, Albany, NY, USA. hkhwaja@albany.edu.

PMID: 36602617
DOI: 10.1007/s10661-022-10787-1

Abstract

Karachi, Pakistan, is a priority site for air pollution research due to high emissions of air pollutants from vehicular traffic, industrial activities, and biomass burning, as well as rapid growth in population. The objectives of this study were to investigate the levels of gaseous pollutants (NO, NO₂, O₃, HNO₃, and SO₂) in Karachi, to determine temporal and seasonal variations, to compare Karachi's air quality with other urban centers, to identify relationships with meteorological conditions, to identify source characterization, and to perform a backward-in-time trajectory analysis and a health impact assessment. Daily samples of gaseous pollutants were collected for six consecutive weeks in each of the four seasons for a year. Daily maximum concentrations of NO (90 parts per billion by volume (ppbv)), NO₂ (28.1 ppbv), O₃ (57.8 ppbv), and SO₂ (331 ppbv) were recorded in fall, while HNO₃ (9129 parts per trillion by volume (pptv)) was recorded in spring. Seasonal average concentrations were high in winter for NO (9.47 ± 7.82 ppbv), NO₂ (4.84 ± 3.35 ppbv), and O₃ (8.92 ± 7.65 ppbv), while HNO₃ (629 ± 1316 pptv) and SO₂ (20.2 ± 39.4 ppbv) were high in spring and fall, respectively. The observed SO₂ seasonal average concentration in fall (20.2 ± 39.4) was 5 times higher than that in summer (3.97 ± 2.77) with the fall 24-h average (120 ppbv) exceeding the WHO daily guideline (7.64 ppbv) by a factor of about 15.7. A health impact assessment estimated an increase of 1200 and 569 deaths due to short-term exposure to SO₂ in fall and spring, respectively. Chronic daily intake estimated risk per 1000 was 0.99, 0.47, 0.45, and 0.26 for SO₂ in fall, NO in winter, O₃ in winter, and NO₂ in spring, respectively. This study confirms the effect of poor urban air quality on public health and demonstrated the influence of photochemical reactions as well as unfavorable meteorological conditions on the formation of secondary pollutants.

Keywords: Gaseous pollutants; Karachi; Nitric acid; Seasonal variation; Urban pollution.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
China
Environmental Monitoring / methods
Environmental Pollutants* / analysis
Nitrogen Dioxide / analysis
Pakistan
Particulate Matter / analysis
Seasons
Sulfur Dioxide / analysis

Substances

Air Pollutants
Nitrogen Dioxide
Sulfur Dioxide
Environmental Pollutants
Particulate Matter

Grants and funding

PGA-7251-07-010/Higher Education Commision, Pakistan