According to The Guardian, approximately one in 10 cases of Alzheimer’s in urban areas could be associated with living near heavy traffic, the study estimated. Scientists in the past linked air pollution and traffic noise to reduced density of white matter in the brain and lower cognition. A recent study suggested that tiny particles from air pollution can make their way into brain tissue.
This study found that those who live close to major traffic arteries were up to 12% more likely to be diagnosed with dementia.
The study, which tracked over 6 million people for more than a decade, could not determine whether pollution is directly harmful to the brain. The increased dementia risk could be an effect of respiratory and cardiac problems caused by traffic fumes or other unhealthy factors associated with living in urban environments. Those living within 50 meters of a busy road had a 7% higher risk in developing dementia, the risk was 4% higher risk at 50-100 metres, 2% higher risk at 101-200 metres and there was no increase in risk in those living more than 200 metres away. Those who lived in a major city, within 50 meters of a major road and did not move during the duration of the study had the highest risk at 12%.