WEATHER EFFECT- AQI 130: CHENNAI AIR POLLUTION LEVEL WORSENS

THERE has been a significant spike in air pollution level in Chennai over the past few days. On Wednesday morning, the city's air quality index (AQI) touched 130, which, as per National Ambient Air Quality Standards stipulated by the Central Pollution Control Board, falls under 'moderately polluted' category, enough to cause breathing discomfort to those with lung, asthma and heart diseases. The city's AQI was near 100 last week, sources said. Gummidipoondi, near Chennai, made it to the list of top 10 polluted cities in India on three of seven days over the past week, sources said.

- SV KRISHNA CHAITANYA

Chennai has seven continuous ambient air quality monitoring stations that provide real-time levels of different pollutants. Of the seven stations, one at Alandur bus depot has recorded AQI of 195, which is close to 'poor' category. Likewise, Perungudi also recorded higher AQI of 164. The AQI in only two stations, Velachery and Royapuram, was below 100, categorised as 'satisfactory', sources said. 

THE dominant and most harmful pollutant is PM 2.5, which peaked to 318 in some of the monitoring stations.

The concentration of harmful particulate matter is several times higher than the prescribed limit. The World Health Organisation prescribes 25 ug/m3 as a safe limit, while India has fixed a standard of 60 ug/m3.