At 249, Baddi records worst AQI in country

The ambient air quality index (AQI) of the Baddi industrial cluster was rated poorest nationally at 249 by the Central Pollution Control Board (CPCB) on the World Environment Day on Thursday, with a higher ozone level being the contributory factor.

As per the board’s data, the ozone level has been increasing consistently from 83 on May 25 to 94 on May 26 while registering 168 by the month end on May 31. It further rose from 177 on June 1 to 249 on May 5, the World Environment Day, though dipped to 189 on Friday.

Out of the eleven parameters that are measured to calculate the ambient AQI level, the value of ozone has been rising for the past nine days while other contentious parameters that usually contribute to poor air quality of Baddi such as particulate matter 2.5 and 10 were found to be within good to satisfactory level.

Officials attributed higher ozone to the rise in

temperature being witnessed in the Baddi industrial cluster.

Experts say the essential raw ingredients needed to form ozone are nitrogen oxides (NOx), volatile organic compounds (VOCs) and sunlight. NOx and VOCs are precursor gases that react in the air in the presence of sunlight to produce ozone.

NOx is produced when fossil fuels like gasoline, oil or coal are burned in power plants, motor vehicles, furnaces, etc. VOCs are also emitted from motor vehicles, chemical plants, refineries, factories and gas stations. If these precursor gases are present under the right conditions, they react to form ozone.

Nearly 20,000 vehicles ply in the Baddi industrial area on a daily basis and industrial fuels like pet coke, coal, etc., are being used in large quantity, thus triggering formation of ozone.