Over 2.7 lakh deaths linked to air pollution in 2023

Over 271,000 people in Bangladesh died from air pollution-related causes in 2023, according to a new global report.

Over 90 percent of those deaths were linked to noncommunicable diseases (NCDs) such as heart and lung ailments, diabetes, and dementia, said the sixth edition of the State of Global Air (SoGA)-2025.

Released early today by the Health Effects Institute (HEI), an independent US-based research organisation, in collaboration with the Institute for Health Metrics and Evaluation and the NCD Alliance, the report places Bangladesh among the countries with the highest air pollution exposure.

Nearly all Bangladeshis live in areas where fine particle air pollution, or PM2.5, exceeds the World Health Organisation's least stringent air quality target of 35 micrograms per cubic metre. Fine particle pollution is the leading cause of air pollution-related disease burden worldwide, it said.

The report provides global estimates of exposure to PM2.5, nitrogen dioxide, and ozone, and their health impacts between 1990 and 2023. It said air pollution was responsible for 7.9 million deaths in 2023, or roughly one in every eight deaths worldwide. Of these, 4.9 million were linked to ambient PM2.5 exposure.

PM2.5 mainly comes from burning fossil fuels in vehicles, power plants, factories, and homes, as well as from agriculture, waste burning, and wildfires.

Public health experts say prolonged exposure to fine particles is driving a surge in chronic illnesses, straining families and the healthcare system. These particles, less than 2.5 micrometres in diameter, can enter the lungs and bloodstream, affecting multiple organ systems and increasing the risk of NCDs such as heart disease, stroke, diabetes, lung cancer, and chronic obstructive pulmonary disease (COPD).

Prof Sohel Reza Choudhury, head of epidemiology and research at the National Heart Foundation Hospital and Research Institute, said fine particles penetrate deep into the lungs, triggering inflammation and disrupting gas exchange, which leads to chronic oxygen deficiency and diseases like COPD.

"That is why the primary impact of air pollution is often seen in respiratory diseases," he told The Daily Star.

However, its effects are not limited to the lungs. "We have also observed significant cardiovascular impacts. In Bangladesh, the rate of premature deaths, especially those caused by heart disease, has risen sharply due to air pollution," he said.

According to the World Health Organisation, NCDs now cause 71 percent of all deaths in Bangladesh, with over half of these being premature. It notes that NCDs are not only a medical challenge but a socioeconomic threat, straining the health system, increasing poverty, and hindering development.

Bangladesh's poor air quality often makes global headlines due to fossil fuel combustion, biomass burning, and emissions from unfit vehicles, brick kilns, and construction work.

The annual Air Quality Life Index report, published in August by the University of Chicago's Energy Policy Institute, said air pollution is cutting Bangladeshis' average life expectancy by 5.5 years, making it the country's deadliest external health risk.

The SoGA-2024 report released in June last year said that at least 236,000 people died due to air pollution in Bangladesh in 2021.

NCD CRISIS, DEMENTIA

The SoGA-2025 report said air pollution is driving Bangladesh's growing NCD crisis, with three out of four COPD deaths linked to poor air quality. It was also responsible for one in three deaths from heart disease, one in five diabetes deaths, and 40 percent of lower respiratory infection fatalities.

The report added that Bangladesh's air pollution-related death rate stands at 156 per 100,000 people, nearly nine times higher than in high-income countries, which average 17 per 100,000.

While health risks from unsafe water and poor sanitation have declined since 2000, the burden of both ambient and household air pollution has increased between 2000 and 2023.

This year, for the first time, the report included findings on the effects of air pollution on people living with dementia. In 2023, dementia linked to air pollution caused more than 5,300 deaths in Bangladesh. Globally, it accounted for 626,000 deaths.

Asked how air pollution contributes to dementia, a physician involved in the noncommunicable disease control programme at the Directorate General of Health Services said tiny airborne particles such as lead, black carbon, and mercury can enter the brain and trigger inflammation and oxidative stress.

"This gradually damages the blood-brain barrier, the protective shield that keeps harmful substances out. As the barrier weakens, memory loss begins, and long-term exposure to polluted air can ultimately be fatal," he said, requesting anonymity.

The SoGA report said that because people with dementia require daily care, rising cases have ripple effects on productivity and family income, with a global economic impact exceeding one trillion dollars annually.

"Women often bear the largest burden, being both more likely to provide care for people with dementia and more likely to develop dementia themselves," it said.

HEI's Head of Global Initiatives, Dr Pallavi Pant, said, "The data highlight the significant impacts of poor air quality on the health and well-being of billions of people, especially those living in Asia and Africa. Growing momentum on air quality management through better monitoring, regulations, and sectoral interventions is yielding progress, but much more is needed to protect those most at risk."

WHAT SHOULD BE DONE

Experts warn that while the government has begun enforcing seasonal brick kiln shutdowns and promoting cleaner energy, these efforts remain insufficient. They emphasised coordinated action across all sectors of government and society.

Prof Choudhury identified emissions from ageing vehicles and poor-quality fuel as Dhaka's main pollution sources. Although authorities in October last year announced plans to remove vehicles over 20 to 25 years old from city roads, there have been no visible changes due to weak enforcement.

"If we can firmly phase out outdated vehicles and gradually shift to battery-powered or electric alternatives, pollution levels could drop significantly," he said, adding that the causes of air pollution are well known and continued exposure is "like knowingly drinking poison".

The SoGA report urged governments to integrate air pollution control into national NCD prevention strategies, noting that reducing pollution can simultaneously lower disease burden, healthcare costs, and climate impacts.