As per the data released by the World Health Organisation (WHO), 14 Indian cities figure in the list of world’s 20 most polluted cities in terms of particulate matter PM2.5 levels in 2016. While, in terms of PM10 levels, 13 cities from India figured among the 20 most-polluted cities of the world in 2016. The particulate matter PM2.5 includes pollutants like sulfate, nitrate and black carbon, which pose the greatest risk to human health. However, PM2.5 is more dangerous than PM10.
To the contrary, Indian Government, in its response to the air pollution data released by the WHO, claimed that various pollution-control measures have led to decline in the pollution levels in 2017. As per the data released by the WHO, Delhi’s PM2.5 level in 2016 was at 143 micrograms/cubic metre, making it the sixth most polluted city in the world.
Moreover, the PM (10) levels in Delhi have also come down in the year 2017 against 2016; PM 10 levels in 2016 were 289 micrograms/cubic metre and in 2017, the levels dropped to 268 micrograms/cubic metre. While, WHO reported PM 10 levels of Delhi at 292 micrograms/cubic metre in 2016.