Air Quality Assessment and Trends in Non-Attainment Cities of Assam (India)

With rapid industrialisation and development in the country, air pollution has posed a major threat to the health of every individual. In the current study, the levels of air pollutants (such as PM, SOx, NOx) of the 5 non-attainment cities of Assam i.e. Nalbari, Nagaon, Guwahati, Sivasagar and Silchar, were compared from the year 2017 to 2021. The study showed that the Air Quality Index (AQI) of Nalbari, Sivasagar and Silchar varied from good to moderate but for Guwahati and Nagaon, it varied from moderate to satisfactory. PM10 was found to be the major contributor. Furthermore, the exceedance factor (EF) for SOx and NOx for all five cities was determined to be L (Low pollution) i.e. less than 0.5, except for Guwahati's SOx concentration, which was M (Moderate pollution) i.e. between 0.5 and 1.0 in 2021. But EF of PM10 varied from M to C (Critical pollution) i.e. more than 1.5 for all the 5 cities from 2017 to 2021. Although, specific initiatives and sustainable techniques were initiated in 2019 under the Nation Clean Air Program (NCAP) to tackle the serious air quality issues in the selected non-attainment cities of Assam; it was found that the PM10 concentrations of Guwahati and Nalbari were found to be high in 2021 i.e. 114 μg/m3 and 92 μg/m3 as compared to 2019 which was 96.7 μg/m3 and 87 μg/m3 respectively. Hence, strict implementation of effective action plans under NCAP along with additional steps that include changes in the lifestyle, will play a major role in improving the air quality of Assam.