Assessing Air Quality and Regulatory Interventions in Tamil Nadu: A Comprehensive Study of Pollutants, AQI Trends, and Health Implications

Abstract

Air pollution has emerged as a critical environmental and public health issue in Tamil Nadu, particularly in rapidly urbanizing districts such as Chennai, Coimbatore, and Madurai. This study investigates air quality trends, identifies major pollutants contributing to Air Quality Index (AQI) fluctuations, and evaluates the effectiveness of policy interventions from 2015 to 2023. Despite the implementation of regulatory frameworks like the National Clean Air Programme (NCAP) and the Graded Response Action Plan (GRAP), periodic spikes in pollution levels persist, raising concerns about the adequacy and enforcement of these measures. The study aims to (i) analyze AQI trends across key districts in Tamil Nadu, (ii) identify the primary pollutants (PM2.5, PM10, NO₂, SO₂, CO, O₃), (iii) assess the correlation between pollutant levels and public health outcomes, particularly respiratory diseases, and (iv) evaluate the impact of regulatory interventions on these environmental and health indicators. Employing a mixed-methods approach, quantitative data were gathered from the Central Pollution Control Board (CPCB), Tamil Nadu Pollution Control Board (TNPCB), and state health departments, while qualitative data were obtained through interviews with environmental officers and healthcare professionals. Analytical tools such as descriptive statistics, correlation analysis, and regression models were used to interpret the data. The findings indicate a gradual but inconsistent improvement in AQI, particularly after 2019, coinciding with targeted interventions. However, concentrations of PM2.5 and PM10 remain high in industrial and traffic-dense areas, posing ongoing health risks. A statistically significant correlation was found between high pollutant levels and increased incidence of respiratory ailments. Although policy measures have shown partial success, their overall effectiveness is limited by enforcement challenges and insufficient public awareness. The study concludes that strengthening local monitoring systems, enforcing stricter emission controls, and enhancing public health infrastructure are essential for achieving long-term air quality improvements and safeguarding public health in Tamil Nadu.