Ambient Air Quality of Guwahati City: A Spatio-Temporal Assessment

Abstract

Today, the air we breathe is being polluted by various natural and anthropogenic sources like accelerated industrialization, haphazard urbanization, rapid increase in human population and ever-burgeoning number of automobiles on the roads. Natural processes absorb these pollutants to a certain extent and air quality is restored, but when the limits are exceeded, pollutants accumulate in the environment and air quality deteriorates. Over the past few decades, human involvement has drastically modified Earth’s chemistry and climate. The emissions from automobiles, prolific or partial burning of fossil fuels, industrial activities and intensification of agricultural practices have escalated the ambient concentration levels of harmful gases like Sulphur di-Oxide (SO₂), Nitrogen di-Oxide (NO₂) and Carbon Monoxide (CO) and of Ozone(O₃) and Suspended Particulate Matter (PM) to worrying levels.

Guwahati, the capital city of Assam and perhaps the most important city of north-easternIndia, has witnessed unprecedentedly high levels of air pollution over the last few years. Clean air should be an unlimited free natural resource and the basic need of all living beings. Against a daily requirement of 2 Kg of food and 3 Litre of water, an adult inhales and exhales about 8 Litre of air every single minute. But when this life-sustaining air gets polluted, it can have dire effects not only on humans but also on plants, animals and all other living organisms.

The present work aims to investigate seasonal variations in air pollution levels through the calculation and analysis of Air Quality Index (AQI) in Guwahati and assess the ambient air quality of the city together with highlighting the health impacts of major pollutants like PM₍₁₀₎, PM_(2.5), SO₂, and NO₂ from 2011 to 2021.