Study of Environmental Emissions from Road Transportation: A case of Bhaktapur Municipality, Nepal

The unprecedented growth of emissions has deteriorated air quality dramatically leading to a pulmonary complication in human health. Especially during the winter season, the prevalence of Chronic Obstructive Pulmonary Diseases (COPD) increases more in females compared to males. Selecting different peak and non-peak hours, this study estimated vehicular emission load with the help of emission factors, derived equations, field visits, and literature review. The average annual vehicular energy demand of Bhaktapur Municipality was estimated at 33,044 GJ while the emission load was estimated at 3,310 tons/year, including (CO2, CO, NOx, HC, and PM10) of which CO2 accounts for 94.36% of total emissions followed by CO (4.39%), HC (0.72%), NOx (0.35%), and PM10 (0.18%), respectively. Statistical analysis showed significant positive correlation (r = 0.92, p = 0.002) between CO2 and PM10, (r = 0.87, p = 0.009) between CO2 and NOx, (r = 0.90, p = 0.004) between CO and HC, (r = 0.74, p = 0.05) between NOx and PM10, respectively. Assuming an inauguration of electric vehicles (Cars, Motorbikes, and Buses) within the Municipality at the rate of 10%, 20%, and 30%, showed a significant reduction in emissions by 157, 314 and 471 tons/year, respectively. The CO2 was found more potent to deteriorating air quality in the future compared to other vehicular pollutants. Despite lower emission load in Bhaktapur Municipality compared to its nearest adjacent city Kathmandu, exponential growth in emissions can become inevitable in the future if clean energy is not promoted in time.