Though last year’s average PM2.5 reading represents a slight improvement from the 153 micrograms per cubic metre in 2013, when Delhi was given the dubious honour of ‘dirtiest city in the world’ by the WHO, even greater strides have been made in China.
PM2.5 is small pollutant particulate matter mostly emitted from coal and oil combustion — it can get deep into lungs and into the bloodstream, increasing the risk of respiratory and cardiac diseases as well as cancer.
The report says the city’s pollution problem has likely increased residents’ risk of lung cancer by nearly 70%, chronic respiratory disease by nearly 50% and ischaemic heart disease by a little more than that.