Influence of weekdays, weekends, bandhas and weather conditions on particulate matter (PM10) concentrations in the Kathmandu Valley in Nepal

Abstract

Particulate matter (PM) exposure has been associated with a variety of adverse health effects. Quantifying the relative source contribution of PM is important as it provides policymakers critical information needed to formulate successful pollution reduction programs. The aim of this study was to evaluate the effects of bandhas (general strikes) and meteorological parameters on PM10 concentrations in the Kathmandu Valley. Within station seasonal differences in PM10 concentrations were compared using t-tests. Linear mixed effects regression models were used to examine the effects of weekends or bandh days on PM10 concentrations. Results showed significant (p<0.001) seasonal variability across all stations. In the urban high traffic (UHT) and urban residential (UR) areas, there were statistically significant (p<0.05) lower PM10 concentrations on weekends. In the UHT, PM10 concentrations were significantly lower on bandh days (p<0.05). These results suggest that a reduction in vehicular emissions may alleviate the PM10 pollution problem in the valley.