Mountains in the Chaning World, Mountains in the Chaning World

Font Size: 
Understanding Human health Burden Associated with Air Pollution in Kathmandu Valley, Nepal
Anobha Gurung

Last modified: 2017-10-05


Air pollution has been linked to acute and chronic health effects. However, the majority of evidence is based in North America and Europe, with a growing number of studies in Asia and Latin America. Nepal is one of the many South Asian countries where little such research has been conducted. Although few studies have examined air pollution and health in Nepal, the existing studies indicate high pollution levels and suggest large health impacts. As understanding the impact of air pollution on health requires estimation of exposure, we developed a landuse regression modeling (LUR) to investigate intraurban variation in air pollution in Kathmandu Valley. Over the study area, at 135 sites, for four sampling campaign, one per season, NO2 was measured. Annual average NO2 by site ranged from 5.7 to 120 ppb for the study area, with higher concentrations in the Village Development Committees (VDCs) of Kathmandu and Lalitpur than in Kirtipur, Thimi, and Bhaktapur, and with variability present within each VDC. In the final LUR model, length of major road, built area, and industrial area were positively associated with NO2 concentration while normalized difference vegetation index (NDVI) was negatively associated with NO2 concentration (R2=0.51). Cross-validation of the results confirmed the reliability of the model. In light to the limited human health studies, we investigated impacts of particulate matter with aerodynamic diameter ≤10μm (PM10) on hospitalization by cause and subpopulation in Kathmandu Valley, Nepal. Time-stratified case crossover analysis was used with interaction terms for potential effect modifiers (e.g., age, sex, socioeconomic status), with adjustment for day of the week, and weather. Daily PM10 averaged 120μg/m3 with daily maximum reaching 403μg/m3. A 10μg/m3 increase in PM10 was associated with increased risk of hospitalization of 1.00% (95% confidence interval, 0.62-1.38%), 1.70% (0.18-3.25%), and 2.29% (0.18-4.43%) for total, respiratory, and cardiovascular admissions, respectively. We did not find strong evidence of effect modification by age, sex, or socioeconomic status. These results in combination with the high levels of exposure indicate potentially serious human health burden from air pollution in the Valley.

Conference registration is required in order to view papers.