Saturday Air Quality Index: Faridabad, Ghaziabad & Delhi still hazardous

Air pollution in the National Capital Region (NCR) continued to be severe on Saturday morning with Gurgaon the least polluted with 330 on the AQI. A score of 300 and above is considered hazardous, up to 50 moderate and between 100 and 150 unhealthy.

Among other cities, air quality in Lucknow (285) and Jaipur (266) continued to be severe. Among the metro cities, Kolkata led the pack with a score of 185. But while Mumbai (112) air was also unhealthy, AQI for Chennai (68) and Bengaluru (55) were far below other cities.

Moscow with a score of just 25 reported good air quality while Dubai (82) was moderate. Singapore reported 76, London 151, Beijing 247 and Bangkok 109.

Air Quality Index is calculated based on averages of all pollutant concentrations measured in a full hour, a full 8 hours, or a full day based on concentrations of five air pollutants: ground-level ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide and particulate matter. The latter describes fine particles in the air between 2.5 and 10 microns across, ‘roughly 1/28th the diameter of a strand of human hair’.

AQI values lower than 50 are considered good. When they exceed 100, they are considered to be “unhealthy for sensitive groups.” Big concerns come around 150-200. Anything over 300 is deemed “hazardous.” New Delhi’s AQI had hit about 1,000 in the early morning hours on Thursday, the worst conditions found just south of Safdarjung Airport.

Within New Delhi and other cities, air quality varied from one part of the city to another. Anand Vihar and Indirapuram in NCR were the worst while South Delhi was relatively better but still hazardous, logging scores of 300 and above.

In 2019, as part of a worldwide survey, it was reported that 21 out of the 30 most polluted cities were in India. PM2.5 figure recorded was 58.08µg/m³, five times higher than the permissible limit recommended by the World Health Organisation (WHO).

Over 50 over cent of this pollution comes from industry, followed by 27 per cent from vehicles, 17 per cent from crop burning and 7 per cent by domestic cooking. Over 2 million Indians lose their life to causes attributed to air pollution.