Assessment of source contribution to ambient air quality through comprehensive emission inventory, long-term monitoring and deterministic modeling

Abstract

In the present study, air pollution monitoring was carried out in Chennai city continuously for more than 3 decades from 1978 to 2016 and air quality trends are established for planning mitigation measures. An extensive air pollution monitoring network consisting of 19 sampling locations covering traffic corridors and intersections, residential, commercial and industrial areas was operated to monitor dust and gaseous pollutants, toxic trace metals, polycyclic aromatic hydrocarbons (PAHs) and other criteria pollutants. Comprehensive emission inventory indicated contribution of pollution load is mainly from transport (80%) followed by domestic (13%), industry (4%), commercial activities (2%) and power back generators (1%). The air pollutant concentrations were high during day time in winter season at traffic corridors, intersections and industrial areas. The monitoring data indicated PM10, PM2.5 and PAHs concentrations were exceeding the limits due to vehicular emissions, road condition (paved and unpaved), construction, industrial and commercial activities. Carbon monoxide and hydrocarbon concentrations were high during traffic peak hours and near road corridors where traffic congestion is high. GM, ATDL and ISCST3 models were employed to assess the contribution of air pollutants from transport, domestic and industry sector, respectively. Performance evaluation of models was also carried out by comparing monitored and model-predicted concentration to assess model prediction accuracy.