Indian capital New Delhi is the reigning king of polluted cities in the world.
Delhi has the highest level of the airborne particulate matter, PM2.5 considered most harmful to health, with 153 micrograms. Not far behind is another Indian city, Patna with 149 micrograms. These figures are six times what the WHO considers a “safe” limit — which is 25 micrograms.
According to a recent World Health Organization report, the capital has six times the levels of airborne particulate matter than are considered safe. Other cities in the country are only slightly better off.
Half of the top 20 cities in the world with the highest levels of PM2.5 were in India, according to the pollution data released by the WHO, which included 1,600 cities. Other cities with high levels were located in Pakistan and Bangladesh.
PM2.5 refers to the diameter measured in microns of particulates such as ammonia, carbon, nitrates and sulfate — which are small enough to pass into the bloodstream and cause diseases such as emphysema and cancer.
The WHO data echoes an earlier study this year which found that air pollution in New Delhi is now worse than Beijing.
No Chinese cities ranked in the top 20 most polluted cities, despite thick, gray smog filling its cities and millions of residents commuting behind surgical masks. Beijing reported 56 micrograms of PM2.5. This year, Chinese leaders have declared “war on pollution.”
elhi has been described as having weak enforcement of pollution controls by India’s Center for Science and Environment, a public interest group.
“Originally designed as compact entities to reduce the length of travel … (Indian cities) are becoming victims of killer pollution, congestion … and a crippling car-dependent infrastructure,” according to the group.
Top 10 most polluted Cities of the World
On World Environment Day, observed annually on 5 June, we have compiled list of the cities with the highest levels of pollution.
Delhi, India (annual mean PM2.5, ug/m3: 153)
Air pollution in Delhi is caused mainly by industry and vehicular traffic, which has released high levels of particulate matter made up of various substances – including carbon, nitrogen, sulphur and metal compounds. According to CNN, there are roughly 8.5 million registered vehicles in the city.
Patna, India (annual mean PM2.5, ug/m3: 149)
The second largest city in eastern India, Patna has an estimated population of 1.68 million as of 2011. It is a major agricultural centre of trade, with its most active exports being grain, sugarcane, sesame and rice.
Gwalior, India (annual mean PM2.5, ug/m3: 144)
Gwalior, one of the largest cities in central India, is surrounded by three main industrial and commercial areas: Sitholi, Banmore and Malanpur.
Raipur, India (annual mean PM2.5, ug/m3: 134)
Raipur has become an important regional commercial and industrial destination for the coal, power, steel and aluminium industries and is the largest market of steel in India.
Karachi, Pakistan (annual mean PM2.5, ug/m3: 117)
Air pollution, lack of proper waste management infrastructure and degradation of water bodies are the major environmental issues in Karachi. The air in the city is rapidly polluted by vehicle emissions from rickshaws and buses, industrial emissions, open burning of garbage and house fires.
Peshawar, Pakistan (annual mean PM2.5, ug/m3: 111)
Vehicular emissions, industrial and brick kiln emissions, the burning of solid waste and refuse and the use of ill-maintained vehicles are some of the sources of pollution in Peshawar.
Rawalpindi, Pakistan (annual mean PM2.5, ug/m3: 107)
A rapidly growing city in the Pothohar region of northern Punjab, Pakistan, Rawalpindi is home to various textile mills. Its high levels of traffic have pushed up air pollution in the region.
Khorramabad, Iran (annual mean PM2.5, ug/m3: 102)
In 2012, pollution contributed to the premature deaths of 4,500 people in Tehran and about 80,000 across Iran, according to the health ministry.
Ahmedabad, India (annual mean PM2.5, ug/m3: 100)
Ahmedabad has become an important economic and industrial hub in India and it is the second largest producer of cotton in the country. Heavy construction work for both infrastructure and housing has contributed to high levels of air pollution.
Lucknow, India (annual mean PM2.5, ug/m3: 96)
The capital city of Uttar Pradesh is among the most polluted cities in the country. The lack of transport infrastructure and growing number of vehicles exacerbates the problem, according to India’s Centre for Science and Environment.
Lucknow, India