Ranking Bangladesh as the world's most air-polluted country, the latest Air Quality Life Index (AQLI) has identified four new densely populated districts in addition to the capital Dhaka as the most vulnerable to air pollution-induced life loss.
Published on Tuesday, the latest AQLI measures that the air of the industrial district Gazipur contains 89.8 particulate pollutants (PM2.5) – the highest in Bangladesh – followed by 88.7 PM2.5 in Noakhali, 87.2 PM2.5 in Dhaka, 88.2 PM2.5 in Cumilla, and 81 PM2.5 in Tangail.
In the previous index, Dhaka, Chattogram, Khulna, Barishal and Mymensingh were the top five vulnerable districts.
If particulate pollution in Bangladesh was under control, or the concentration of PM2.5 remains within 5 micrograms per cubic metre (μg/m3) as per the World Health Organization (WHO) guidelines, residents in Gazipur, Noakhali, Dhaka, Cumilla and Tangail would gain more than eight years of life expectancy, according to the AQLI. The AQLI is released by the University of Chicago's Energy Policy Institute.
Measured in terms of life expectancy, particulate pollution is the second greatest threat to human health in Bangladesh (closely following cardiovascular diseases), taking 6.8 years off the life of the average Bangladeshi, according to the index.
In contrast, tobacco use reduces average life expectancy by 2.1 years, while child and maternal malnutrition reduces average life expectancy by 1.4 years.
PM2.5, a fine particulate matter of 2.5 micrometres or less in diameter, is the most dangerous pollutant because it can penetrate the lung barrier and enter the blood system, causing cardiovascular and respiratory disease and cancers.
Despite a 2.1% dip in particulate pollution compared to 2020 levels, pollution in Bangladesh has hovered around 14 to 15 times the WHO guideline for the past decade.
Air pollution researcher Dr Abdus Salam, a chemistry professor at Dhaka University, told The Business Standard that the entire Bangladesh – except a small part in the east namely Sylhet – becomes covered in polluted air in the dry season.
"The internal sources are brick kilns, rice mills and the unfit transports that are all run on low-quality fuels. Besides, the transboundary particulate pollutants that flow from the north to south through the winter breeze also severely pollute Bangladesh's air quality," Professor Salam said.
WHO recognises air pollution as the single biggest environmental threat to human health. Every year, exposure to air pollution is estimated to cause 7 million premature deaths.
Preventive medicine specialist Dr Lelin Chowdhury told TBS that air pollution causes most respiratory diseases while asthma patients suffer the most.
Lelin observes that every year, air pollution adds new tuberculosis and asthma patients with troubles like respiratory system allergies, sneezing and coughing.
"Apart from the respiratory system, the kidney and liver are also damaged because of the pollution. Air pollution is also responsible for lung cancer," Lelin said.
According to the Bangladesh Bureau of Statistics, the average life expectancy of people in Bangladesh is about 72 years and four months.
However, Dr Lelin does not think the average life expectancy in Bangladesh, although has increased, is a standard.
"Due to pollution, various diseases ruin our standard of life," Lelin adds.
Although there is no official record of air pollution-related death in Bangladesh, the National Institute of Diseases of the Chest and Hospital in Dhaka treated over 2,10,000 patients, both outdoor and in emergency in 2021. Seven years ago, the number was 85,000.
Air pollution affects more people than other pollutants and has health impacts even at very low concentrations. By reducing air pollution levels, countries can reduce the burden of disease, and long and short-term illnesses, AQLI says.
All of Bangladesh's 164.8 million people live in areas where the annual average particulate pollution level exceeds both the WHO guideline and the country's own national standard of 15μg/m3. Even in the least polluted district of Sylhet, particulate pollution is 9.7 times the WHO PM2.5 guideline and 3.2 times the national standard.
Bangladesh, India, Nepal, and Pakistan-where 22.9% of the global population lives—are the top four most polluted countries in the world.
Between 2013 and 2021, particulate pollution increased by 12.4% in Bangladesh, following 9.5% in India, and 8.8 in Pakistan, the index shows.
Meanwhile, China has had staggering success in combating pollution since declaring a 'war on pollution' in 2014, reducing its pollution by 42.3% from 2013 to 2021 and extending its population's average life expectancy by 2.2 years.
Air pollution researcher Professor Salam credits multiple measures by China to check its air pollution.
"China has shut down almost all of its coal-fired industries. Besides, China's strict traffic rules restrict the use of dirty fuel and unfit transport. If we compare the measures with Bangladesh, we can easily say why Bangladesh is failing to check air pollution," he concluded.