Twice as bad: Delhi’s PM 2.5 now 17 times safe limit

After the World Health Organization revised its air quality guidelines on Wednesday for the first time in 16 years, the air safety standards have become stricter. Delhi’s annual PM 2.5 average for last year is around 17 times the new WHO-recommended safe annual limit. The revised WHO guidelines make it tougher for Delhi to meet global standards, and experts wish for a revision of the Indian standards for PM 2.5 too, which is currently eight times the annual WHO limit at 40 micrograms per cubic metre.