Air pollution linked to risk of hospital admission with dementia
Written by Eleanor Bird, M.S. on November 3, 2020 — Fact checked by Mary Cooke, Ph.D.
A study of over 63 million people in the United States finds that air pollution exposure increases hospital admission risk for neurological conditions, including Alzheimer’s disease and other dementias.
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The burden of neurodegenerative disease is rising. According to estimates from Harvard’s NeuroDiscovery Center, in 30 years, more than 12 million people in the U. S. will receive a diagnosis for neurodegenerative disease.
The progressive loss of neurons causes neurodegenerative diseases, including Alzheimer’s disease, the most common form of dementia, and Parkinson’s disease.
Although increasing rates of these conditions are partly due to an aging population, the way we live may also be increasing their likelihood.
The National Institute of Environmental Health Sciences (NIEHS), for example, fund a range of research to investigate what these factors might be, including exposure to pesticides, toxic metals, such as lead, and air pollution.
Air pollution, in particular, seems to have a strong connection with neurological disease. A landmark study in 2016 found that magnetite — a potentially toxic particle in polluted air — was able to get into human brain tissue.
A further study found a significant association between residential air pollution and receiving a diagnosis with dementia in London, United Kingdom. More recently, scientists have shown that even young people exposed to air pollution show markers of neurodegenerative disease.
New research led by Harvard T. H. Chan School of Public Health adds to the evidence on this, finding that levels of fine particulate matter — tiny particles with a diameter of 2.5 micrometers or under — in the air have associations with hospitalization for neurodegenerative disease in a U.S. cohort.
The study, published in The Lancet‘s Planetary Health journal, uses the largest ever dataset to assess the link between air pollution and neurological disorders.
The study, which is the first nationwide cohort study to look at the association between fine particulate air pollution and neurodegenerative disease in the U.S., uses data from over 63 million people. Everybody in the study was a Medicare-fee-for-service beneficiary over the age of 65.
The researchers investigated the connection between long-term exposure to fine particulate matter and hospital admissions with a diagnosis of Parkinson’s disease or Alzheimer’s disease and related dementias.
The researchers estimated air pollution exposure by zip code and based hospital admissions information on almost 17 years’ worth of data spanning 2000–2016.