Environmental Impact Assessment and Determination of Air Quality Study in Chennai Region, Tamilnadu, India.

Abstract

Urban air pollutants, pose a major health problem in most developing countries, especially India. Prolonged exposure presents a significant carcinogenic risk. This study analyzes NO₂, SO₂, PM_2.5-bound heavy metals and  PM_2.5-bound PAHsin108samplescollectedduring 2018-2019 at a suburban industrial site in the Chennai, Tamil Nadu. NO₂ and SO₂ were found to be within acceptable levels but PM_2.5 exceeded the limits of both CPCB and WHO guidelines. The NWR plots used for pollutant source contributions pointed to high probabilities for local pollutant sources at low wind speeds (< 5m/s). The levels of heavy metals in PM_2.5 and the diagnostic ratios of PM_2.5-bound PAH further confirmed vehicular and industrial emissions to be the sources. The 96-h back trajectory and cluster analysis showed the air masses from the South-Western and North Eastern directions influencing the pollutant levels at the monitoring site. Health Risk Assessment showed varying levels of risk for various pollutant constituents. The Incremental upper-bound Lifetime Cancer Risk (ILCR) via inhalation exposuretoPM_2.5-boundPAHwasatthe‗low‘risklevel(15.4x10^-5).To improve air quality, close attention should be paid to controlling vehicular and thermal plant emissions.