DEGRADATION OF AIR QUALITY (PM10) WITH SEASONAL CHANGE AND HEALTH RISK ASSESSMENT IN METRO CITY KOLKATA

Abstract

Over the last few years, the whole nation is consistently facing a severe level of air pollution during the winter season. Air pollution level in all over India has started to get aggravated during the post-monsoon season due to an association of both atmospheric and anthropogenic factors. PM10. i.e. inhalable particles with a diameter less than or equal 10 micrometres, is a criteria air pollutant out of total twelve in India having great importance. In this study, seasonal variation of PM10 concentration was measured near Jadavpur, Kolkata from December 2017 to March 2018. During the study period results of ambient air quality monitoring data for the average concentration of PM10 ranged between 103.67 – 323.70 µg/m3. It is observed that in 100% of the cases, the 24hr average concentration of PM10 contravened the NAAQS (100 μg/m3) limit. The maximum concentration of PM10 was observed during the winter season (238.81±63.12 μg/m3) from January to February. To understand the existing air quality scenario, the Air quality index (AQI) value is computed based on PM10 concentration which is belonged to ‘Moderate’ to ‘Poor’ categories. It is observed that in December about 43% of days belong to the ‘poor’ category and 57% is of ‘moderate’, wherein the month of January only 25% days are a part of the moderate category, and the rest are of poor category. In the case of February month, only 17% of poor days are observed, and the air quality scenario gets improved with approaching summer season as in March air quality became moderate. Thus it is noticed that PM10 is a critical pollutant at this site in Kolkata. In this study, the number of higher rates of mortality and morbidity risk, respiratory diseases, cardiovascular diseases and chronic obstructive pulmonary disease risk for an exposed population is also estimated due to exposure to PM10.