Pollution levels in the city on the night of Diwali went up from the previous year’s figures for the festival night and were much above the permissible limits for most pollutants. According to data collected by the Haryana State Pollution Control Board (HSPCB), the suspended particulate matter (PM) 2.5 was 13 times above the permissible limit and almost double the levels measured on Diwali last year.
On Sunday night, the maximum level of PM 2.5, which has a permissible limit of 60 micrograms per cubic metre (µg/m³), increased to 785µg/m³. Similarly, sulphur dioxide increased from 1.20 µg/m³ on Saturday to 9.8 µg/m³ on Sunday. However, that is much below the permissible limit of 20 µg/m³.
PM2.5 is particulate matter 2.5 micrometres or less in diameter and is a major component of what constitutes air pollution. The particulate matter being very fine it can reside in the lungs and aggravate asthma or respiratory conditions. The elderly and children are most vulnerable to adverse effects on health caused by PM2.5.
According to the Central Pollution Control Board (CPCB) data, which is being provided by the HSPCB, initial data on Monday showed that the PM2.5 level was 223 µg/m³.
The city was also affected by smog on Monday morning as the air quality level declined. Last year on Diwali, the maximum PM 2.5 level was recorded at 361 µg/m³. State pollution board officials said that the smog was a result of the pollutants released from bursting of firecrackers on Sunday still being trapped in the atmosphere.
Harmful gases such as sulphur dioxide (SO2), nitrogen oxide (NO) and nitrogen dioxide NO2, apart from particulate matter, are released when firecrackers are burnt. A combination NO and NO2 forms NOx or mono-nitrogen oxides.
The official data also marked an increase in NOx from 10.14 µg/m³ last year to 50.56 µg/m³ this year. NOx can cause inflammation of the airways and lungs, and reduce immunity. It also intensifies asthma attacks, especially among children.
“There is a sudden increase in pollution levels after Diwali. Due to high moisture in the air, pollutants remain trapped in the atmosphere for longer periods. This is why the PM 2.5 level is high a day after Diwali. A good shower can clean up the air of the region. However, the next couple of days will be harmful for residents as the air will remain polluted,” said Bhupender Singh, regional officer, HSPCB.