Delhi no longer most polluted, but 4 other cities in top 7

New Delhi, ranked worst in in 2014, is no longer the world's most polluted city but four other Indian cities were among the top seven most polluted cities, the WHO said today warning that over 80 per cent of the world's city dwellers breathe poor quality air.
According to a new World Health Organisation (WHO) report based on data collected between 2008 and 2013, New Delhi was the 11th most-polluted city while four other Indian cities - Gwalior (2), Allahabad (3), Patna (6) and Raipur (7) - figured in the top seven cities with worst air pollution.
The report warned that over 80 per cent of the world's city dwellers breathe poor quality air.

New Delhi, which was ranked worst in terms of air pollution in 2014, was listed 11th this time. This comes after a string of measures were taken by both the Centre and the Delhi government including levying of environment cess and implementation of 'odd-even' scheme to regulate traffic.
In a sample of selected mega-cities with a population above 14 million, New Delhi was however the most polluted, followed by Cairo and Bangladesh's capital Dhaka.
New Delhi's air quality was measured by the presence of PM2.5 which had an annual average measurement of 122.

10 other Indian cities were also among the top 20 polluted cities in the world. In WHO's 2014 report, 13 out of 20 most polluted cities were in India. According to the WHO report, Delhi's annual mean PM10 was 229.

Zabol in Iran figured as the city with most dirtiest air.
Delhi Chief Minister Arvind Kejriwal tweeted, "Latest WHO report- Delhi no more most polluted city. Congrats Delhiites."
Tracking the presence of harmful pollutants like sulfate and black carbon, WHO found that air quality was generally improving in richer regions like Europe and North America, but worsening in developing regions, notably the Middle East and the Southeast Asia.
Urban residents in poor countries are by far the worst affected, WHO said, noting that nearly every city (98 per cent) in low- and middle-income countries has air which fails to meet the UN body's standards.

"Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health," Maria Neira, the head of WHO's department of public health and environment, said in a statement.
Greenpeace India said the report has re-emphasised the
urgent need to address the issue of air pollution in cities such as Gwalior, Allahabad, Patna and Raipur, along with New Delhi.
The UN body has said that overall, contaminants in outdoor air caused more than 3 million premature deaths a year.
The quality of air pollution data provided by individual countries varies considerably, and WHO does not compile a ranking of the world's most polluted cities.

Crucially, key African centres like Nigeria's mega-city Lagos, were excluded from the list because of the sparse availability of air quality data in many parts of the continent.