By Shishir Prashant 
PrashantNews
A day after Diwali celebrations, air pollution levels remained high in the national capital as well as Uttarakhand’s capital Dehradun, with Delhi recording an Air Quality Index (AQI) of 344 in the ‘very poor’ category and Dehradun registering 257 in the ‘poor’ category at 4 pm on Monday, according to Central Pollution Control Board (CPCB).
The readings highlighted the deteriorating air quality in both cities following Diwali celebrations, with the national capital facing a considerably higher pollution burden than Dehradun.
According to the AQI classification of the Central Pollution Control Board (CPCB), an index between 201 and 300 falls in the ‘poor’ category, while readings between 301 and 400 are classified as ‘very poor’. An AQI above 400 is categorised as ‘severe’.
Delhi witnessed a thick blanket of smog on Monday morning, with reduced visibility in several areas. Several monitoring stations in the capital recorded AQI levels above 400, indicating severe pollution. The city’s average AQI was around 370 in the morning, according to monitoring data, with fine particulate matter (PM2.5) emerging as the major pollutant.
The deterioration in air quality has once again raised concerns over the impact of firecracker emissions, vehicular pollution, construction dust and seasonal factors such as stubble burning on air quality in north India.
Dehradun, which generally enjoys relatively cleaner air than the national capital, also witnessed a significant deterioration in air quality. The AQI reading of 257 placed the city in the poor category, raising concerns about the impact of festive emissions and other sources of pollution.
The deterioration in Dehradun’s air quality is particularly worrying as pollution levels had already started rising in the run-up to Diwali.
Experts have cautioned that firecracker smoke, combined with low wind speeds and cooler weather conditions, can cause particulate pollutants to remain suspended in the atmosphere for longer periods.
Children, elderly people and those suffering from asthma and other respiratory ailments are particularly vulnerable to exposure to polluted air. Health experts generally advise people in affected areas to avoid strenuous outdoor activities when pollution levels are high.