Long-term exposure to air pollution associated with lower semantic memory

· News-Medical
Kathryn Conlon, senior author, associate professor, UC Davis Department of Public Health SciencesSemantic memory is essential for communication, comprehension and navigating everyday life. Our findings suggest that long-term exposure to air pollution doesn't just affect physical health - it may also shape how the brain ages, particularly in ways that matter for independence and quality of life."

Two other measures of cognitive function - executive function and verbal episodic memory - did not show an impact related to the pollution.

Reducing air pollution may reduce dementia burden

Black adults in the United States experience 1.5 to 2 times higher rates of Alzheimer's disease and other dementias compared with non-Hispanic White adults.

Methods and findings

The researchers analyzed data from 740 adults, aged 53 to 94, who were participants in the STAR study. Individual-level long-term average PM2.5 exposures were computed by averaging daily estimates of PM2.5 levels at the participants' residential addresses.

Cognitive performance was assessed for semantic memory, verbal episodic memory and executive function. They evaluated associations with 5-, 10-, and 17-year average PM2.5 exposure.

The researchers found:

  • People who were exposed to higher levels of PM2.5 pollution over many years scored noticeably lower on semantic memory tests than those exposed to lower levels of pollution.
  • The association with PM2.5 pollution persisted even after accounting for other factors such as age, education, income and marital status.
  • The effect of long-term PM2.5 exposure on semantic memory was greater than what researchers would expect from 10 years of normal aging.

Lowering air pollution could lower Alzheimer's burden

How individuals can reduce exposure to air pollution

While air pollution is largely a community-level issue, there are many ways individuals can reduce their exposure to air pollution:

  • Check daily air quality forecasts on AirNow. The EPA website lets you enter your ZIP code to find out about air quality, which accounts for fine particulates, in your area.
  • Limit outdoor activity when pollution levels are high, especially during wildfire smoke events.
  • Use high-efficiency (HEPA) air filters indoors.
  • Keep windows closed on poor air quality days.
  • Avoid exercising near busy roads or heavily trafficked areas.
  • Use recirculated air settings in vehicles during heavy traffic or smoky situations.

Source:

University of California - Davis Health

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