Gurgaon: Air quality index gives hope, pollutants start to dissipate

Although Gurgaon’s air quality was marked ‘very poor’ over the last two days, it inched up to ‘poor’ on Sunday as pollutants started to clear

After being marked ‘very poor’ for the last two days, the city’s air quality index (AQI) inched up marginally to ‘poor’ on Sunday, as the pollutants in the air started to clear. The AQI on Sunday was recorded at 285.

A further improvement in the city’s air quality will reduce the risk of respiratory illness. (Parveen Kumar/HT PHOTO)

On Saturday, the AQI slipped to 345, which, however, was less than the previous day’s reading of 397.

Though the level of air pollution is still high in the city, the concentration of pollutants in the air has gone down over the last two days, said environment experts. They further maintained that the pollutants are likely to dissipate further in the coming days.

If true, residents of Delhi-NCR have a reason to smile as the toxic level in the air will decline. However, as of now, the level of pollutants in the air is high and could affect anyone in the event of exposure.

The most prominent pollutants that affect air quality of the city are carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), nitrogen oxides (NOx) and sulphur dioxide (SO2).

The pollution watchdog said that the air quality in Gurgaon keeps dropping to alarming levels due to untamed pollution from vehicular emission and construction and demolition waste. Highly polluted stretches in the city include MG Road, Iffco Chowk, Rajiv Chowk, Golf Course Extension Road and internal roads in sectors 3 and 4.

“The level of pollutants in the city, which spiked abnormally after Diwali, is starting to hit normal levels. We are following the graded response action plan in the city. We have asked the authorised body to carry out periodic mechanised sweeping on roads with heavy traffic and sprinkle water on unpaved roads and along the road where construction work is going on,” JB Sharma, regional officer, Haryana State pollution Control Board (HSPCB), said.

Read I Gurgaon breathes a bit easier this year after Diwali

Experts on air quality were of opinion that the level of pollutants and the air quality cannot be monitored by just one monitoring station.

Anumita Roychowdhury, executive director-research and advocacy, Centre for Science and Environment (CSE), said, “To monitor the air quality of Gurgaon, there’s a need for more air monitoring stations which can provide data on all pollutants. The data can be used to formulate a long term plan to combat air pollution.”

The air quality index is an indicator of the air pollution from the levels of three pollutants that includes NO2, PM 10 and PM 2.5. The air quality is marked ‘good’ if it is anywhere between 0 and 100, moderate if it is between 101 and 200 and poor if between 201 and 300.

The index for individual pollutants at a monitoring location are calculated as per its 24-hour average concentration value (8-hour cycle in case of CO and Ozone) and health breakpoint concentration range.

All pollutants cannot be monitored at all locations. Overall, the AQI is calculated only if data on a minimum of three pollutants is available.