Is Breathing Dangerous? "Fine Particulate Matter Negatively Impacts Alzheimer's"

Higher PM2.5 Levels Linked to Increased Risk of Alzheimer's Disease

Research has found that air pollution has a direct impact on the onset and progression of Alzheimer's disease.

Seoul Jongno-gu downtown view. Photo is not related to the specific content of the article. Photo by Jo Yongjun

According to MedPage, a U.S. medical news outlet, a research team led by Dr. Edward Lee at the Perelman School of Medicine, University of Pennsylvania, recently published findings indicating that air quality is associated with Alzheimer's disease pathology and cognitive decline.

The team analyzed 602 autopsy cases collected at the University of Pennsylvania from 1999 to 2022. The subjects included individuals with dementia such as Alzheimer's disease, those with movement disorders, and a control group. The study was adjusted for demographic factors and the presence of the apolipoprotein E (APOE)4 genotype, which is the strongest genetic risk factor for Alzheimer's disease.

The analysis revealed that individuals who were frequently exposed to fine particulate matter (PM2.5) before death were more likely to show severe neuropathological changes associated with Alzheimer's disease. In 287 cases with available clinical dementia rating scores, exposure to PM2.5 was also linked to worsening cognitive and functional impairment.

The median age at death among the study subjects was 78, and 54.5% were male. Most participants were white (94.4%), and the median education level was 16 years. More than half (53.2%) carried the APOE4 allele.

More than half of the subjects exhibited severe Alzheimer's disease pathology, with 62.3% showing high levels of Alzheimer's disease pathology. For every 1 microgram per cubic meter (1㎍/m³) increase in PM2.5 concentration, the likelihood of more severe amyloid staging or overall neuropathological changes associated with Alzheimer's disease increased by 17% to 20%, respectively.

The researchers stated, "We confirmed that one pathway by which air pollution negatively affects the brain is through the worsening of Alzheimer's disease pathology," adding, "While there may be other mechanisms, such as the exacerbation of cerebrovascular disease, this study focused on the neurodegenerative process."

This research is also connected to recent findings published in the American scientific journal Science, which reported that exposure to fine particulate matter is associated with the development of Lewy body dementia. Additionally, the Lancet Dementia Commission has identified air pollution as a major modifiable risk factor for dementia prevention.

However, the study has limitations, as the demographic characteristics of the autopsy subjects were skewed, making it difficult to generalize the findings to other populations. Furthermore, due to the nature of the research program, there were many Alzheimer's disease patients but very few with vascular dementia. The research team noted, "The actual association between PM2.5 and cerebrovascular disease may be even stronger than indicated by these results," and added, "Other confounding factors may also have influenced the findings."

PM2.5 refers to particulate matter with a diameter of 2.5 micrometers (㎛) or less. In Korea, environmental standards for PM2.5 have been in effect since 2015, with the annual average air quality standard set at 15㎍/㎥. According to the Ministry of Environment's Air Quality Annual Report, the annual average PM2.5 concentration in Seoul in 2023 was 20㎍/㎥.

This content was produced with the assistance of AI translation services.