Delhi most polluted capital city; 22 of top 30 polluted cities are in India

Brick kilns, vehicles emitting sulphur main cause of pollution

UN rapporteur terms air pollution silent, prolific killer

Every hour, 800 people die suffering diseases caused by polluted air

Bangladesh has the most polluted air in the world and Dhaka is the second most polluted capital city, according to a new study.

“At a country level, weighted by population, Bangladesh emerges as the most polluted country,” said the 2018 World Air Quality Report released yesterday. Greenpeace and AirVisual, who monitor global air quality, prepared the report based on last year's data collected from public monitoring sources.

Gurgaon, a suburb of the Indian capital New Delhi, is the world's most polluted city, says the report, which ranks Dhaka 17th in that category.

Take mouse cursor on the interactive map to see the air pollution status of the countries

According to the report, air pollution will cause around 7 million premature deaths globally next year and have a major economic impact.

Bangladesh, one of the most densely-populated countries in the world, has been struggling with air pollution for long. Dhaka, the country's capital, often finds its place among the most polluted cities in global indices.

Brick kilns and vehicles run on fuel with higher level of sulfur have been identified as the major sources of air pollution in the country.

But Md Ziaul Haque, director (air quality management) of the Department of Environment (DoE), said there was confusion in the report which placed Bangladesh at the top in the country category.

“The average air quality of Dhaka and the entire Bangladesh are different. The air in rural areas and other districts is much healthier than in Dhaka,” he said.

According to the report, four of the five most polluted countries in the world are in South Asia. Bangladesh is followed by Pakistan, India, Afghanistan and Bahrain.

The quality of air in Iceland, Finland and Australia are among the healthiest, the report shows.

Delhi is the most polluted capital city while Dhaka is second in that category followed by Kabul, Manama and Ulaanbaatar of Mongolia, according to the report.

The report said seven of the top 10 most polluted cities in the world are in India. Gurugram is followed by Ghaziabad and Faisalabad (Pakistan). Indian cities of Faridabad, Noida, and Bhiwadi come next in the category.

The city ranking shows Asian locations dominating the highest 100 average PM 2.5 during 2018, with cities in India, China, Pakistan and Bangladesh occupying the top 50 spots.

The report focuses on PM2.5 as a measurement of air pollution. PM2.5 refers to particulate matter (ambient airborne particles) which measure up to 2.5 microns in size, and has a range of chemical makeup and sources.

Due to its small size PM2.5 is able to penetrate deep into the human respiratory system and from there to the entire body, causing a wide range of short- and long-term health effects, the report said.

In a statement, Yeb Sano, executive director of Greenpeace Southeast Asia, said, “Air pollution steals our livelihoods and our futures, but we can change that.

“In addition to human lives lost, there is an estimated global cost of $225 billion in lost labour, and trillions in medical costs. This has enormous impacts on our health and on our wallet”.

Talking to The Daily Star, DoE Director Ziaul said in Bangladesh, brick kilns were the major source of air pollution followed by construction work.

He claimed that the government has taken various steps to reduce emission of harmful smoke from brick kilns, including promoting cement blocks for construction work.

In a report by US-based Environmental Protection Index (EPI) on the environment performance by the government of 180 countries, Bangladesh ranked 179, having slipped down by 40 places from the year 2010 to 2018. The report was published in September last year.

According to the DoE and the World Bank, brick kilns make up 56 percent of the country's air pollution.

The government had enacted a law in 2018 to make these kilns environment friendly, but a recent report indicated that of the 7,772 brick kilns in the country, 2,123 have not converted to the required modern and environment-friendly technology.

Meanwhile on Monday, David Boyd, special rapporteur on human rights and the environment, insisted that air pollution was a “silent, sometimes invisible, prolific killer” which affected women and girls more than men.

“Air pollutants are everywhere, largely caused by burning fossil fuels for electricity, transportation and heating, as well as from industrial activities, poor waste management and agricultural practices,” he said at the Human Rights Council in Geneva.

Air pollution is present both inside homes and outside and is responsible for the premature death of seven million people each year, including 600,000 children, according to the special rapporteur's UN environmental annual report.

“Every hour, 800 people are dying, many after years of suffering, from cancer, respiratory illnesses or heart disease directly caused by breathing polluted air,” he said, before highlighting that effective measures could have prevented those deaths.

Why PM2.5?

The report focuses on PM2.5 as a representative measure of air pollution. PM2.5 refers to particulate matter (ambient airborne particles) which measure up to 2.5 microns in size, and has a range of chemical makeups and sources. PM2.5 is widely regarded as the pollutant with the most health impact of all commonly measured air pollutants. Due to its small size PM2.5 is able to penetrate deep into the human respiratory system and from there to the entire body, causing a wide range of short- and long-term health e­ffects. Particulate matter is also the pollutant group which a­ffects the most people globally. It can come from a range of natural as well as man-made sources. Common sources of PM include combustion (from vehicle engines, industry, wood and coal burning), as well as through other pollutants reacting in the atmosphere.