Research shows that traffic-related air pollution in Irvine weakens brain function

Researchers at the University of California, Irvine, have found that exposure to traffic-related air pollution in Irvine led to memory loss and cognitive decline and triggered neurological pathways linked to the onset of Alzheimer’s disease.

“The link between air pollution and Alzheimer’s disease is concerning as the prevalence of airborne toxins is not only increasing globally, but also close to home here in Irvine,” said corresponding and senior author Masashi Kitazawa, Ph.D. ., associate professor of environmental and occupational health in the UCI public health program. “Our findings are just one example of what particulate matter can do to brain function.”

The results of the study will be published in the journal Toxicological Sciences.

Alzheimer’s disease is the most common cause of dementia in the elderly and is a growing public health crisis in the US and several other countries. Despite extensive research into all aspects of Alzheimer’s disease, its exact origins remain elusive. While genetic predisposition is known to play a prominent role in disease progression, mounting evidence suggests that environmental toxins, particularly air pollution, may cause Alzheimer’s disease.

Kitazawa and his team compared mouse models at two ages. Researchers exposed a group of 3- and 9-month-old mouse models for 12 weeks to ultrafine particles via ambient air collected in Irvine. A second group was exposed to purified air. The different ages were used to determine the potential impact of particulate matter exposure during very vulnerable life stages: growing young people and the elderly.

Researchers conducted tests related to memory tasks and cognitive function and found that both benchmarks were compromised by particulate matter exposure. Notably, they also found that their older models (12 months at the time of analysis) showed a buildup of brain plaque and activation of glial cells, both of which are known to increase the inflammation associated with the onset of Alzheimer’s disease.

“Air pollution is one of the few prominent, modifiable environmental risk factors in Alzheimer’s disease,” said study co-author Michael Kleinman, Ph.D., adjunct professor of environmental and occupational health in UCI’s Program in Public Health. “Public and environmental regulators must accelerate their efforts to reduce particulate matter levels to reduce the risk of Alzheimer’s disease and other serious health problems.”

Kitazawa added: “This evidence is alarming and it is imperative that we take action to adopt effective and evidence-based regulation, spread awareness about lifestyle changes and work together to improve our air quality.”