Spatial-Temporal Assessment of Air Pollutants and Environmental Quality in Nashik District: Evaluating the Influence of Electric Vehicle Adoption

Abstract

Urban air pollution is a growing environmental concern in rapidly expanding cities due to increasing vehicular emissions, industrial activities and urbanization. The transition toward electric vehicles (EVs) has emerged as a promising strategy for reducing transportation-related emissions and improving urban environmental quality. This study evaluates environmental changes associated with EV adoption in Nashik city, Maharashtra, through the development of an Environmental Pollution Index (EPI) using the Analytic Hierarchy Process integrated with Geographic Information System techniques. Air quality monitoring data from four stations, namely Gangapur Road, Hirawadi, MIDC Ambad and Pandav Nagari, were analyzed for a ten-year period from 2017 to 2026, representing the pre-EV phase (2017-2021) and the EV expansion phase (2022-2026). Major air pollutants including PM2.5, PM10, NO2, SO2, CO and O3 were considered together with supporting environmental indicators such as vehicular density, temperature, relative humidity and electric vehicle registration trends. AHP was used to determine parameter weights which were integrated through GISbased weighted overlay analysis to generate spatial EPI maps. The results indicate that PM2.5 concentrations decreased from about 63-66 µg/m3 during the early years to nearly 48 µg/m3 by 2026 while PM10 concentrations declined from about 118 µg/m3 to nearly 91-92 µg/m3 . Nitrogen dioxide concentrations also reduced from approximately 42-44 µg/m3 to around 31 µg/m3 , representing a decline of about 21- 25 % in traffic-related emissions. Carbon monoxide levels decreased from approximately 0.92 mg/m3 to about 0.65 mg/m3 during the study period. Electric vehicle registrations increased from fewer than 500 vehicles in 2017 to more than 13,500 vehicles by 2026, indicating rapid adoption of electric mobility. Spatial Environmental Pollution Index mapping revealed that industrial areas such as MIDC, Ambad exhibited relatively higher pollution intensity compared with residential zones such as Gangapur road and Pandav nagari. The comparison between pre-EV and post-EV scenarios showed a noticeable reduction in high pollution zones and an expansion of moderate and low pollution categories across several parts of the city. The COVID-19 lockdown period during 2020-2021 also showed temporary improvements in air quality due to reduced transportation activity. Overall, the integrated AHP-GIS framework effectively captures spatial and temporal environmental changes associated with EV adoption and provides a useful approach for urban environmental monitoring and sustainable transportation planning.