Living Near a Motorway Increases Dementia Risk: New Study Highlights the Link to Air Pollution

 

Living near motorway linked to higher dementia risk

Researchers in the UK and China have uncovered a significant link between living near a motorway and an increased risk of developing dementia. Individuals residing less than 1,000 meters from major traffic roads face a 14% higher likelihood of developing this neurological condition. The study found that exposure to pollution from road traffic is consistently associated with a higher incidence of dementia and smaller brain structure volumes.

Elevated levels of nitrogen dioxide and PM2.5, known pollutants harmful to human health, were identified as key contributors to the heightened dementia risk. Brain MRI scans on participants also revealed changes in brain structures associated with Alzheimer's disease at the pre-symptomatic stage.

The researchers noted, "Traffic proximity was consistently associated with smaller volumes of brain structures, including peripheral cortical gray matter and gray matter, all of which were associated with pathological changes in Alzheimer's disease."

Previous research has linked dementia to a reduced volume of gray matter in the brain. Furthermore, traffic emissions are a significant source of ultrafine particles capable of penetrating the brain. Air pollution can trigger neuroinflammation, an immune response that, if overactive, can cause neurological damage.

In London alone, an estimated one-third of the population, approximately 3 million people, live near busy roads. Previous studies have indicated that living within 50 meters of a major road can increase the risk of developing lung cancer by up to 10%.

Currently, 79% of areas in the UK exceed the World Health Organization's (WHO) annual mean guideline for fine particulate matter levels.

This study was conducted by researchers from China's Peking University and the University of Leicester, analyzing Biobank data from 460,901 people living in Britain over a median period of 12.8 years. Wuxiang Xie, an associate professor at Peking University's Clinical Research Institute, suggested that mitigating air pollution could be a viable strategy to reduce the dementia risk associated with traffic exposure.

A separate study published by University College London found that air pollution policies could prevent 6,751 early deaths among adults in the UK by 2030, compared to a scenario with no regulations in place.