Air pollution linked to dementia, caused 626,000 deaths worldwide in 2023

For the first time, the State of Global Air 2025 report quantifies how dirty air affects the brain, broadening pollution's toll beyond heart and lung diseases

Air pollution is no longer just a respiratory or heart health issue. According to the State of Global Air 2025 report, air pollution contributed to 626,000 dementia-related deaths in 2023, accounting for 29 per cent of all global dementia deaths.

 

The report also found that polluted air robbed humanity of 11.6 million healthy years of life, marking the first time the role of air pollution in dementia has been quantified.

 

With more than one in four dementia deaths linked to air pollution, the findings highlight a growing threat for the world’s ageing population as chronic exposure to fine particulate matter (PM2.5) harms not only the lungs and heart but also the brain.

 

 

Air pollution and brain health

 

The report shows how microscopic pollutants can travel from the lungs into the bloodstream and eventually reach the brain. Once there, these fine particles can trigger inflammation and oxidative stress, damaging brain tissue and accelerating neurodegeneration.

 

This process increases the risk of  Alzheimer’s disease, vascular dementia, and mild cognitive impairment - conditions that cause gradual loss of memory, reasoning, and independence.

 

Air pollution exposure also affects brain development and functioning in younger people, increasing the risk of neurodevelopmental conditions such as autism and psychological disorders like anxiety and depression.

 

While behavioural factors such as smoking or poor diet remain key contributors to dementia, researchers note that air pollution affects billions of people, meaning even a small individual risk translates into a massive global burden.

 

Double burden for women

 

The dementia crisis also highlights a gendered dimension. Women are more likely both to develop dementia and to serve as caregivers for those affected. The report notes that this dual role deepens the social and economic costs of the disease, particularly in low- and middle-income countries where health systems are already strained.

 

Globally, 60 million people were living with dementia in 2021, with 10 million new cases emerging each year. As life expectancy rises, the number is expected to grow sharply, especially in regions with high pollution levels.

 

Ageing populations, growing risk

 

The study warns that the health toll of air pollution will intensify as the world ages. Older adults are more vulnerable to the chronic effects of long-term exposure, especially in areas with limited healthcare access.

 

In 2023, 86 per cent of air pollution deaths were due to noncommunicable diseases (NCDs) such as heart disease, chronic obstructive pulmonary disease (COPD), diabetes, and dementia. Overall, 7.9 million deaths were linked to air pollution making up about one in every eight deaths worldwide.

 

South Asia and parts of Africa carry the heaviest burden, with India and China together accounting for more than 50 per cent of all air pollution-related deaths.

 

Urgent call for cleaner air

 

The report emphasises that reducing pollution could yield wide-reaching benefits including lowering healthcare costs, extending healthy lifespans, and even slowing climate change.  Experts say the new evidence should serve as a wake-up call for governments and policymakers worldwide.

 

“Many people in decision-making roles are often at ages where the impacts can be more pronounced. Clean air action is an important way of helping ensure good health and better quality of life for all,” said Pallavi Pant, head of global initiatives at the Health Effects Institute, Boston.

 

Pant, who oversaw the preparation of the State of Global Air 2025 report, added, “The data highlight the significant impacts of poor air quality on the health and well-being of billions of people around the world, especially those living in Asia and Africa. We hope this report helps strengthen the demand for and drive action towards cleaner air where it’s needed most.”

   

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