A decline in pollution levels during Diwali was witnessed in Tamil Nadu, Karnataka and Telangana
With toxic smog choking Delhi and other parts of north India, the southern states breathed slightly better air after Diwali.
In Tamil Nadu, the air quality index (AQI) improved in several areas as compared to last year.
Chennai's Valasarvakkam, which recorded the worst AQI (365) on Diwali last year, witnessed a 67% improvement. The capital city's Besant Nagar recorded the least pollution with an AQI of 207, marking a 60% decrease from the last year.
Tamil Nadu police filed over 2,200 cases for violating the Supreme Court guidelines on bursting firecrackers during Diwali celebrations. The police also arrested more than 2,000 people for violations, who were later released on bail.
A similar decline in pollution levels during Diwali was also witnessed in Karnataka and Telangana.
While the AQI in Bengaluru was pegged at 108, it was 168 in Hyderabad.
An air quality index between zero and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".
While an AQI level of 400-500 impacts healthy people and seriously impacts those with existing diseases, an AQI level of 301-400 causes respiratory illness on prolonged exposure. An AQI level of 201-300 and 150-200 may bring discomfort to people with lungs, asthma, and heart diseases.
P Sudhakar, the Director of the CPR Environmental Education Centre, attributed the improved air quality index to favourable weather conditions and lower humidity. He also said that the time limit to burst firecrackers also played a key role.
"There were favourable weather conditions and lower humidity. There was also increased adherence to time restrictions for bursting firecrackers," he said on major contributors to the reduced pollution levels.