Indoor Air Quality Assessment in Electric Vs. Diesel BRTS Buses in Ahmedabad, India

Air pollution in urban areas poses significant health risks, with indoor levels often exceeding outdoor levels by up to tenfold. This study evaluates indoor air pollution (PM10, PM2.5 and CO2) on three Bus Rapid Transit System (BRTS) routes in Ahmedabad, focusing on electric and diesel buses. Data was collected during morning, afternoon, and evening using a sensor-based portable device alongside manual recordings of bus occupancy. Results show higher PM10 and PM2.5 concentrations in electric buses than in diesel ones, with peak pollution concentration in the evening. CO2 concentrations in both bus types significantly correlated with occupancy (electric bus R² = 0.946, diesel bus R² = 0.996). However, PM10 levels had low significance with occupancy (electric bus R² = 0.447, diesel bus R² = 0.325). In diesel buses, PM2.5 levels strongly correlated with occupancy (R² = 0.886). This research highlights the need for further studies on indoor air quality in mass transportation systems in developing countries.