Title: Air pollution exposure and health impacts in the Kathmandu valley

Authors: Srijan Lal Shrestha; Pierpaolo Mudu; Peter DeCarlo

Addresses: Central Department of Statistics, Tribhuvan University, Kirtipur, Kathmandu, Nepal ' Environment, Climate Change and Health, World Health Organization (WHO), 20 Avenue Appia, CH-1211, Geneva, Switzerland ' Department of Environmental Health and Engineering, Johns Hopkins University, 2400 North Charles Street, Baltimore, MD 21218-2608, USA

Abstract: Air pollution monitoring in Kathmandu valley during 2003-2007, 2014-2015 and 2017 onwards shows that there has been substantial decrease in particulate air pollution with around 50% reduction in overall average PM₁₀ from 123 μg/m³ for the period 2003-2007 to 61μg/m³ during 2018-2020 equivalent to around 3.2% decrease per year from 2003 to 2020. Similarly, a reduction of 13.6% in PM₂.₅ from 49 μg/m³ during 2014/15 to 42.4 μg/m³ during 2017-2020 was found with around 4.2% decrease per year from 2014-2015 to 2020. However, the averages are still 3-4 times higher than WHO 2005 guideline values and pose serious threats to the valley inhabitants. Assessment of respiratory health burdens like chronic obstructive pulmonary disease and acute respiratory infection including pneumonia showed 6%-13% of the respiratory morbidities can be attributed to PM₂.₅ in Kathmandu valley. Under 35% PM₂.₅ reduction scenario in 2030, the expected avoidable fractions are found to be 2.5-4.9%.

Keywords: ambient air pollution; attributable burden; avoidable burden; health effects; Kathmandu valley; ozone; particulate matter.

DOI: 10.1504/IJENVH.2021.122312

International Journal of Environment and Health, 2021 Vol.10 No.3/4, pp.213 - 242

Received: 20 May 2021
Accepted: 07 Sep 2021
Published online: 19 Apr 2022 *