ANALYSING THE AIR QUALITY OF ASANSOL, WEST BENGAL, INDIA WITH REFERENCE TO PM10, PM2.5 AND NO2 (STUDY PERIOD: 2013 TO 2018)

Abstract

The industrialised city of Asansol has always been under the scanner because of its air-quality. The present study analyses the air quality of Asansol on the basis of secondary data, with reference to particulate matter (size 10 µm and 2.5 µm) and NO2. As per data obtained from the WBPCB, there has been an increasing trend of the average annual values of PM10 since 2013, peaking in 2016 and dipping in the subsequent years of 2017 and 2018. However, the annual average concentration was still considerably higher than the recommended standards. In 2018, 49% days had PM 2.5 levels above the recommended standards, dropping to 33% in 2019. The city’s air quality worsens during the winter months i.e. between October and March. As per PM2.5 data of 2018 and 2019, the PM2.5 values peak between the months of October and March. Air quality data gathered between 1 st. October 2017 and 28 th. February 2018 reveals that PM10 levels reach the categories of “very poor” to “severe” conditions during the winter months in Asansol thereby contributing to more days with smog formation. The worsening air quality during winter is often attributed to winter specific weather conditions like temperature inversions and the prevalent practice of crop residue burning around Asansol. Data obtained between 2013 and 2018 indicate that the long-term annual average trend of the gaseous pollutant NO2 has declined over the years meeting standards for the year 2017 and 2018 thereby displaying implementation of apt measures in the motorisation and industrial sector.