Air Pollution Linked to Nearly 188,000 Dementia Cases in the U.S. Every Year, Study Shows
A new study published in the journal JAMA Network Open reveals that air pollution may be responsible for nearly 188,000 dementia cases in the United States each year. The research suggests that exposure to bad air quality from wildfires and agricultural activities significantly increases a person’s risk of developing Alzheimer’s disease and other forms of dementia later in life.
The study, based on data collected from a decades-long survey backed by the National Institutes of Health, followed up with thousands of older adults across the country every two years to assess their health. These findings were then combined with detailed air quality modeling, which estimated the level of exposure to specific sources of air pollution in each individual’s residential area.
The study primarily focused on PM 2.5 air pollution, which refers to very small particles that can be inhaled from the air. These particles, which are less than 2.5 micrometers wide, can come from various sources such as vehicle exhaust and wildfire smoke. They have been linked to a range of health issues, including coughing, shortness of breath, worsening asthma, and an increased risk of heart disease.
“The environmental community has been working very hard for the past 10 to 15 years to be able to predict exposures,” said Sara Adar, associate chair of epidemiology at the University of Michigan’s School of Public Health. The researchers accounted for multiple emission sources such as coal-fired power plants, agriculture, wildfires, and traffic in their modeling, enabling them to assess the impact of each source on dementia risk.
Even after adjusting for various potential factors that could affect the results, such as sex, race, ethnicity, education, and wealth, the study found that the higher risk of dementia remained significant. However, the researchers acknowledged that they did not have enough data to account for every possible exposure or difference in every individual’s life, which can impact the results.
“Dementia takes a long time to develop. It’s more likely to build up over a lifetime,” said Adar. The study also highlighted the role of other types of air pollution associated with wildfires and agriculture in contributing to the increased dementia risk. Toxic molecules carried by the smoke from wildfires and the reaction of ammonia released by farming activities can further worsen air pollution and potentially harm the brain.
The researchers hope that their findings will lead to more targeted interventions to address the dementia risk associated with air pollution. Unlike other common risk factors for dementia, such as hypertension and diabetes, air pollution can be modified at the population level, making it an ideal target for large-scale prevention efforts.
As scientists continue to highlight the range of health risks associated with air pollution, it becomes increasingly important to prioritize efforts to reduce pollution levels and protect public health.