Source: Live mint,
New Delhi, Sep 5, 2017:- There
were 4.24 million deaths globally in 2015 attributable to PM2.5—fine
particulate matter with a diameter less than 2.5 micrometer—of which the share
of India’s 1.09 million deaths is 26%, according to the latest report of the
World Health Organization (WHO). PM2.5 are more harmful to human health than
PM10 (particles with a diameter between 2.5 and 10 micrometer) because unlike
PM10—which only goes down to the lungs—PM2.5 can enter the blood supply from
the lungs and turn into invisible killers. Among megacities—cities with the
population of at least 14 million—Delhi has the worst air quality, according to
the WHO report. Delhi witnessed widespread public protests in November 2016
after the city was engulfed in a toxic smog when the PM2.5 level rose to 999
micrograms (mg)/metre cube (m3)—16 times higher than the Indian ambient air
quality standard of 60mg/m3, and 40 times higher than the WHO standard of
25mg/m3—on a 24-hour average basis.