India tops global indoor air pollution with highest annual PM2.5 levels

New Delhi: India has topped a global indoor air pollution chart with the highest average annual PM2.5 levels followed by China, Turkey, UAE and South Korea, according to a study.

Moreover, on the list of cities with highest average annual PM2.5 levels, national capital Delhi was on the top amongst the cities, followed by Beijing, Shanghai, Shenzhen and Busan, a Dyson statement said.

The Dyson Global Connected Air Quality Data project analyses more than half a trillion data points, to understand user behaviours and compare indoor and outdoor air quality.

It further said: PM (Particulate Matter) 2.5, which is a mixture of solid and liquid particles, is used for describing pollutant levels.

PM 2.5 levels are fine particles that have a diameter less than 2.5 micrometers, more than 100 times thinner than a human hair and remain suspended in the air for longer durations and pose health risks as they can enter into the respiratory tract.

"The study reveals that air inside our homes can be significantly worse, particularly during the winter season, with PM2.5 levels exceeding health standards set by WHO. Winter was, in general, the most polluted season across the markets – even in the southern hemisphere – where colder weather traps polluted air nearer to ground level," it said.

Pollution peaks in the winter season, especially in Delhi, with November and December being the most polluted months. (PTI)