THIRUVANANTHAPURAM: When the air quality in the nation’s capital is plummeting at an alarming rate, the analysis of the quality of air during Diwali in the state has offered reassurance, with the air quality index (AQI) being largely found to be Good.While the AQI in Delhi skyrocketed and crossed well over 300, putting air quality to the category of Very Poor, that in Thiruvananthapuram stood at 41.07, placing air quality in the Good category.
The Kerala State Pollution Control Board (KSPCB) which monitors air quality on a daily basis is preparing a report after analysing it in the state on the seven days leading up to Diwali. In Kochi and Kozhikode too, the values have been observed to be Good.
"There is no emergency situation in the state, considering the values of AQI. The values are within the limits and the air quality was good during the Diwali days too," said S Sreekala, member secretary, KSPCB. Meanwhile, KSPCB is moving towards the source apportionment study. “This is to ascertain the major sources of pollution which can aid in identifying the source and thereby help come up with a policy-level intervention to curb pollution,” said Sreekala.
The data in three metros have been arrived at through the air quality monitoring stations at Plamoodu (for Thiruvananthapuram); Palayam (for Kozhikode) and Eloor, Vyttila, MG Road (for Ernakulam)The data analysis of the AQI on the seven days leading to Diwali in the three metros of Thiruvananthapuram, Kochi and Kozhikode finds that although the air quality was attributed to ‘Good’, it dipped slightly on the two days of Diwali bash, alternately in Thiruvananthapuram and Kochi.
The air quality based on the continuous ambient air quality monitoring dated October 26 and 27 shows the quality of air in the capital as Satisfactory. As per the figures on October 28 and 29 showed, the status of air quality improved to Good.On all the other days, the quality was observed to be good at all the three metros. On Diwali days, the AQI is being arrived at by considering the amount of PM 10 and PM 2.5 in the air.
“During Diwali, the major pollutants include the particulate matter (PM). It is the PM that is less than 2.5 microns that cause respiratory diseases and air quality is ascertained using PM 10 and PM 2.5. The pollutants considered for arriving at the AQI can be different, considering the nature of the place,” said Smitha Sasikumar, assistant scientist, KSPCB.
According to Premalatha S, environmental engineer, KSPCB, 70 per cent of the pollution in the state has been attributed to vehicular emission while the rest 30 per cent is due to burning, emission from industries and crop burning, among others. “So the focus currently is on finding the source of the pollution,” she said. A detailed report of the AQI across the state during the Diwali is being prepared and will be submitted to the Central Pollution Control Board.
Particulate matter (PM)
The particulate matter (PM) refers to fine particles suspended in air, most of which are dangerous to human health. PM 10 refers to matter that is less than 10 microns in width while PM 2.5 refers to particles less than two and one-half microns or less in width and is considered to be more dangerous to respiratory health.
What are the pollutants?
The National Ambient Air Quality Standards (NAAQS) include twelve pollutants -PM10, PM2.5, Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Carbon Monoxide (CO), Ozone (O3), Ammonia (NH3), Benzene (C6H6), Benzo (a) Pyrene (BaP), Arsenic (As), Nickel (Ni) and Lead (Pb). The air quality data of various pollutants are converted into a single number to get the Air Quality Index (AQI). The quality of air is then ascertained using the AQI. There are six AQI categories -Good, Satisfactory, Moderately polluted, Poor, Very Poor and Severe. These categories are arrived at by considering the ambient concentration values of air pollution and their health impact.
Preparing air quality report
The air quality report in the state is being prepared after ascertaining the air quality on seven days- three days before and after the Diwali along with the quality on the festival night. The same will be submitted to the Central Pollution Control Board (CPCB).
New air quality monitoring stations
Four new air quality monitoring stations are being set up in the state, one each at Thrissur, Kannur, Thiruvananthapuram and Kollam. The station at Kollam will be commissioned soon while the one in Thiruvananthapuram will be set up at the Kariyavattom campus.