Air pollution has been linked to a rise in dementia in a new major review carried out on behalf of the UK Government.
The link between air pollution and an increased risk of declining brain function was confirmed on Tuesday after researchers analysed dozens of human studies.
The review, carried out on behalf of the UK Health Security Agency, concluded it was “likely that air pollution can contribute to a decline in mental ability and dementia in older people”.
Researchers believe the primary way this happens is through small toxic particles seeping into the bloodstream after they are breathed into the lungs.
The particles, or pollutants, then irritate the blood vessels and end up disrupting circulation to the brain, which over time can lead to vascular dementia.
In rare cases, the review found that very tiny air pollution particles can go through the blood-brain barrier and damage the neurons directly.
The 290-page report was led by Professor Frank Kelly, from the School of Public Health at Imperial College, and carried out by the Committee on the Medical Effects of Air Pollutants (COMEAP).
Researchers analysed 70 human studies, including population-based research, taken from the general public, and experiments in a laboratory.