Decentralized Emission Inventories and Traffic Dynamics: A Comprehensive Study on PM2.5 and PM10 in the Road Sector of Greater Chennai

Abstract

In this study, decentralized emission inventories were developed for the road sector in selected areas of Greater Chennai, with a specific focus on PM2.5 and PM10 emissions across four distinct periods: pre- and post-lockdowns, semi-lockdowns, and lockdowns. Land use types include residential, commercial, and industrial. It comprises 10 sampling stations: Anna Nagar, Ambattur, T.Nagar, Porur, Valasaravakkam, Koyembedu, Maduravayol, Kilpauk, Alandur, and Kodambakkam. Methodology included primary surveys to assess traffic patterns and mode preferences, monitoring vehicle volumes, and calculating emission rates in grams per second per square meter (g/s-m2). Utilizing primary surveys, the existing travel and transportation features were assessed to understand traffic patterns and mode preferences. Vehicle emission rates in grams per second per square meter (g/s-m²) for both PM2.5 and PM10 were determined for all ten stations. The study unveiled that the volume of vehicles commuting to the Koyambedu region is 2.5 to 5 times greater than in other areas. Modal shares varied, with two-wheeled vehicles constituting 33%, buses 25%, four-wheelers and three-wheelers 24%, and Vehicles for hauling goods 18%. Location with the greatest pollutant concentration proved Koyambedu at 0.000158 g/s-m², correlating with its elevated vehicular inventory. Prompted by the current air quality status, this study underscores the necessity to accurately estimate particulate matter emissions from vehicles and understand their impact on air quality.