A new study has found that a small increase in air pollution caused by small toxic particles increases the risk of dementia by 16%.

Researchers from the University of Washington used decades of data from two long-term projects in Puget Sound, one on dementia risk factors and one on air pollution.

In addition to the increased risk of dementia, the researchers found that the same small increase in air pollution increased the risk of Alzheimer’s disease by 11%.

The study suggests that improving air quality could be a key strategy to reduce dementia, especially in high-risk neighborhoods.

It is well known among environmental researchers that air pollution can lead to respiratory problems ranging from asthma to lung cancer.

One particularly dangerous type of pollution is called fine particulate matter, or PM2.5, so named because the particles are 2.5 micrometers wide, about 30 times smaller than a human hair.

PM2.5 pollution is associated with vehicle exhaust, construction sites, chimneys, fires, and other sources.

This contamination has been linked to an increased risk of severe Covid-19 infection.

Recent research has also established links between PM2.5 pollution and dementia, and the decline in memory and thinking ability that often affects older adults.

The new study, published Wednesday in the journal Environmental Health Perspectives, provides evidence of this trend.

University of Washington (UW) researchers investigated decades of data on the development of dementia and air pollution in the Seattle, Washington area.

Most studies on dementia risk achieve five years of data or less, making this new research unique in a long period of time.

For those patients diagnosed with dementia during the study period, the researchers investigated their exposure to air pollution using air quality data, which has been measured regularly in Seattle since 1978.

Using detailed data about where the patients lived, the researchers were able to determine how much PM2.5 pollution they were exposed to, and how this compares to patients who did not develop dementia.

The result was astonishing: a small increase in long-term exposure to pollution led to a significant risk of developing dementia.

“We found that an increase of 1 microgram per cubic meter of exposure corresponds to a 16% greater risk of all-cause dementia,” said Rachel Shaffer, lead author and a doctoral student in environmental health at the University of Wisconsin.

This amount (one microgram per cubic meter), equals the pollution difference between downtown Seattle and a remote residential area.

The researchers also found that an increase of one microgram per cubic meter increased the risk of Alzheimer’s disease by 11%.

These comparisons were made over 10 years of exposure.

This study provides key evidence for the contribution of air pollution to dementia and other neurological conditions.

In another recent study, released at the Alzheimer’s Association International Conference, researchers said improving air quality is an essential dementia prevention strategy.