Delhi no more world's most polluted city says World Health Organization

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Delhi no more the most polluted city in the world, says WHO report

Delhi is not the most polluted city in the world any more, according to the World Health Organisation's (WHO) urban air quality database released on Thursday.
In fact, it now ranks 11th among 3,000 cities in 103 countries in terms of PM 2.5 (fine, particulate pollution) and 25th in terms of PM 10 (coarse pollution particles) levels. This is though a considerable improvement since 2014 when Delhi was ranked the most polluted city in terms of PM 2.5 levels, WHO had monitored only 1600 cities last time. This time 1400 more cities have been included in the database.

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Zabol in Iran is the most polluted city in the world according to the database. Gwalior and Allahabad are a close second and third in terms of PM 2.5, which is associated with more serious health impacts than PM 10. Patna and Raipur rank 6th and 7th. Totally, four Indian cities are among the world's ten most polluted cities, 10 out top 20 are also in India. In WHO's 2014 report, 13 out of 20 most polluted cities were in India.
Delhi's annual PM 2.5 mean for 2013 (second half) is 122 micrograms per cubic metres according to WHO's latest report compared to 153 micrograms per cubic metres as per WHO's previous report. Delhi's annual mean is about three times the Indian safe standard and 12 times the WHO standard of 10 micrograms per cubic metres. Chinese cities Xintai and Baoding are at ninth and 10th in the ranking, Beijing ranks far below at 56th. Beijing was at 75th last time. Sinclair in US is the least polluted city with an annual mean of only 2 micrograms per cubic metres.
WHO used data from various government and research organisations for the database, it's based on ground measurements of annual mean concentrations of particulate matter (PM 10 and PM 2.5) and "aims at representing an average for the city or town as a whole, rather than for individual stations. Years of measurements range from 2010 to 2015, unless the latest available data was older," the report said.
Experts said Delhi's efforts to control air pollution may have reflected in the improvement in ranking. Some however also raised an interesting point - WHO has been mainly focusing on particulate matter (PM) but not so much on oxides of nitrogen (NOx) which is a problem in many parts of the West. "To get a more accurate and balanced picture of air quality globally, WHO should have taken NOx in to account too. NOx levels are in high in many parts of Europe too," said an expert.
Global trends since 2008 show air pollution levels have gone up by 8% despite improvements in many cities. WHO in its statement also said urban air pollution levels were lowest in high-income countries, with lower levels most prevalent in Europe, the Americas, and the Western Pacific Region but highest in low-and middle-income countries in eastern Mediterranean and South-East Asia Regions, with annual mean levels often exceeding 5-10 times WHO limits.

"It is crucial for city and national governments to make urban air quality a health and development priority," said WHO's Dr Carlos Dora. "When air quality improves, health costs from air pollution-related diseases shrink, worker productivity expands and life expectancy grows. Reducing air pollution also brings an added climate bonus, which can become a part of countries' commitments to the climate treaty," he added. During the World Health Assembly, between 24-30 May, member states will discuss a road map for an enhanced global response to the adverse health effects of air pollution.
"Delhi has improved. Ahmedabad has stabilized and Patna has worsened. We have seen that Delhi has managed to arrest the declining air quality trend in 2015. Air policy action has started kicking in - with an environment compensation charge on on trucks, action against other sources. We are responding to action but the levels are still very high in the city, it only shows that action has to be sustained to meet clean targets," said Anumita Roy Chowdhury, executive director, Centre for Science and Environment (CSE).

"I am not surprised that four Indian cities are in the top ten list. In 2014, 13 out of top 20 cities were from India. Our fossil fuel consumption has increased since then. In India there are also multiple sources of particulate matter emissions that need to be addressed urgently like industries, thermal power plants, and biomass burning. The environment ministry has recently announced standards for thermal power plants. That's a welcome solution but we need an action plan now and will have to move away from a fossil fuel dependent economy," said Sunil Dahiya, campaigner with Greenpeace India.

Delhi no more the most polluted city in the world, says WHO report - Times of India
 
Delhi, Allahabad and Raipur among most polluted cities in the world, says WHO report

Around 98 percent of cities in low- and middle-income countries with more than 100,000 inhabitants have air pollution levels that exceed WHO guidelines, with the South East Asia region registering an increase of over five percent increase in dirty air over the five years, a new UN study revealed.

A database released by the World Health Organisation (WHO) compares a total of 795 cities across 67 countries for levels of small and fine particulate matter (PM10 and PM2.5) during the five-year period, 2008-2013. PM10 and PM2.5 include pollutants such as sulfates, nitrates and black carbon. PM2.5 are very fine particles that can penetrate deep into the respiratory system and can be directly linked to the greatest risks to human health for stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma.
Overall, 80 percent of people living in urban areas that monitor air pollution are exposed to air quality that do not meet WHO guidelines. "The trend is for worsening air pollution in low-and middle-income countries overall and improving air quality in the higher-income country,” said WHO's Dr Carlos Dora. The number of exposed people in urban centres to pollution-heavy air falls to 56 percent for high-income countries. WHO called the overall trend "worrying”.

The annual mean PM2.5 levels for a few busy cities were: Beijing 85 μg/m3, Shanghai 52 μg/m3 , Islamabad 66 μg/m3 (for 2011 collected from one station), Istanbul 33 μg/m3 (for 2012), Paris 18μg/m3 (for 2014), London 15 μg/m3 (for 2013) and New York-Northern New Jersey 9 μg/m3 (for 2014).

WHO does not rank countries but merely reproduces data from the government and other sources and analyses them.

One of the worst quality of air for the 3000 cities which find a mention in this WHO database is the Iranian city of Zabol with PM2.5 levels recording a whooping 217 μg/m3 dirty particles in 2012. One of the cleanest airs is of the Arctic city of Kiruna which had only 2 μg/m3 of PM2.5 in 2013.

WHO's air quality guidelines recommend keeping PM2.5 levels within 10 μg/m3 for annual mean numbers and 20 μg/m3 annual mean for PM10 levels.

Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health,” says Dr Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants of Health.

However, the good news is that more than half of the monitored cities in high-income countries and more than one-third in low- and middle-income countries reduced their air pollution levels by more than five percent in five years.
"It is possible to do things even if you are low-and middle-income countries to improve your air quality and it is being shown,” Dr. Dora said.
PM10 levels for 39 cities selected across WHO regions for the period between 2011-2015 show Riyadh to be, by far, the most polluted city with dirty particulates of 370 μg/m3 in the air followed by Doha (about 260 μg/m3), Delhi (about 225 μg/m3), Greater Cairo, Dakar and Ulanbator. The lowest in the comparative chart is Toronto.

PM10 levels of 11 mega cities with more than 14 million habitants between 2011 and 2015 shows Delhi (about 225 μg/m3) to be the most polluted followed by Cairo (175 μg/m3), Dhaka (160μg/m3), Kolkata (140 μg/m3), Mumbai (120 μg/m3), Beijing (110 μg/m3), Shanghai (75 μg/m3). Istanbul, Mexico City, Sao Paulo and Buenos Aires follow Shanghai in ambient urban air pollution levels.

Annual mean PM10 measurements could be accessed in only 586 cities in low-and middle-income countries.

Indian cities don't fare very well on this database . The annual mean PM2.5 levels - that represents the greatest environmental risks to health-are alarmingly high above the UN health agency's guidelines for most cities. Some of the most choked air is in Gwalior (176 μg/m3) followed by Allahabad (170 μg/m3), Raipur (144 μg/m3) Ludhiana (122 μg/m3), Delhi (122 μg/m3), Lucknow (113μg/m3) The numbers for all cities are for 2012 while for Delhi the level has been calculated from 2013.

Only Tezpur with an annual mean PM2.5 level of 6 μg/m3 has air comparable to European cities.
Ambient air pollution is the greatest environmental risk to health-causing more than 3 million premature deaths worldwide ever year.
The odd-even road rationing policy adopted in some cities of the world like Delhi and Mexico is "very useful” but is essentially a stopgap arrangement because they improve things "momentarily”, Dr Dora told Firstpost .

"But in the long-term you need more structural measures. You need better transportation systems, rapid bus transit system, you need space for cycles, you need space for pedestrians, reduction in the number of vehicles which are on the road vis-à-vis the number of people (etc.),” the expert added.

Describing the challenges in India as huge, the WHO said that cooking with wood, coal or kerosene is a very big problem in the country. "India has 400 million homes using kerosene for lighting, still. Even if they are doing solar which is very good… it's a lot of particles, it is very bad stuff. And it is easily solved because you have solar lamps that are very effective, they are cheap,” he said.

India, Bangladesh and China where more and more cities are "going in the wrong direction”, waste burning is one of the biggest causes of air pollution, the experts said. The dominant reasons for dirty air is different for countries across the world. For instance, in New York 50 percent of the outdoor air pollution comes from heating and cooling of a few, large buildings. However, in Europe, in many parts it is ammonia contained in fertilisers that is the cause while in Africa dirty sources of electricity play a big role in clogging the air.

"Most sources of urban outdoor air pollution are well beyond the control of individuals and demand action by cities, as well as national and international policymakers to promote cleaner transport, more efficient energy production and waste management,” the WHO said in a statement.

During the World Health Assembly to be held later this month governments will huddle together to discuss a road map for an enhanced global response to the adverse health effects of air pollution.

Delhi, Allahabad and Raipur among most polluted cities in the world, says WHO report
 
Delhi is n't first place, but still polluted among Indian cities
 
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