On June 7th, 2023, New Yorkers woke up to an unfamiliar scene: an orange-colored sky above New York City’s skyscrapers. New York Times reported that this was the historically worst air pollution in NYC. Other parts of the United States are experiencing similar air pollution due to the forest fires in Canada. Today, we will explore how exposure to air pollution could affect our cognitive health.
What is the Cause of Air Pollution?
The current air pollution was caused by forest fires in British Columbia and Alberta in the west side of Canada and Quebec on the east side of Canada, moving south towards the United States. Half of the forest fires are caused by humans, while the other half are ignited by lightning strikes. According to the Wall Street Journal, May of 2023 was the hottest May in British Columbia and Alberta.
Other types of air pollution include smog (a form of air pollution when combusted fossil fuels react with sunlight), pollen/mold (exposed within a residential apartment/house), and asbestos.
What Is In the Air Pollution?
Such wild forest fires produce gaseous pollutants (such as carbon monoxide), hazardous air pollutants (HAPs) (such as polycyclic aromatic hydrocarbons [PAHs]), water vapor, and particle pollution. Particle pollution is a term used to describe a mixture of solid and liquid droplets suspended in the air.
According to the United States Environmental Protection Agency, particles in particle pollution can be made up of different elements, such as biological materials (e.g., pollen and mold spores), acids (e.g., sulfuric acid), inorganic compounds (e.g., ammonium sulfate, ammonium nitrate, and sodium chloride), organic chemicals, soot, and metals.
You will often see in news articles notations such as PM10 or PM2.5. PM10 means particulate matter 10 micrometers or less in diameter, PM2.5 is particulate matter 2.5 micrometers or less in diameter. PM2.5 is generally described as fine particles. AQI is another acronym that is often used to indicate air pollution level. AQI stands for Air Quality Index. It was a range of values. For example, good air quality AQI ranges from 0 to 50, moderate air quality ranges between 51 and 100, and unhealthy for sensitive groups ranges between 101 and 150. There are more ranges with higher AQI values.
What are the Effects of Air Pollution on Cognitive Health?
A 2014 study conducted by Columbia University researchers showed that when pregnant mothers are exposured to PAHs (Polycyclic Aromatic Hydrocarbons), the likelihood of the child developing Attention-deficit/hyperactivity disorder increased. A 2022 study in China showed similar results. Other types of disorders due to prenatal exposures to air pollution include lower birth weight, smaller brain size, autism spectrum disorder, and lower IQ score.
For older adults, exposure to air pollution may lead to cognitive decline, neurodegenerative diseases, and osteoporosis. Following about 4000 people from 1978 to 2018, a 2021 study found that higher 10-year average exposure to air pollution increases the risk of all types of dementia. Another study published in 2020 followed about 60 million people from 2000 to 2016 and found increased likelihood of having a Parkinson’s disease or Alzheimer’s disease among those who had a higher exposure to air pollution. A 2023 study found that postmenstrual women who were exposed to air pollution were more likely to have osteoporosis.
A 2020 study cites multiple studies to explain why air pollution might be associated with cognitive decline. The authors explain that proteins such as Tau and beta-amyloid deposits in the brain, which have been found to be associated with neurodegenerative diseases, are also linked to hypertension and other cardiovascular diseases. Cardiovascular diseases, in turn, are associated with stroke and cerebrovascular diseases. The author suggests that air pollutants such as nitrogen oxide and ozone may cause inflammation in the brain and cause cognitive impairment and neurodegenerative diseases. A 2014 study showed an association between exposure to nitrogen oxide and cognitive impairment among older adults in Los Angeles, California.
Exposure to air pollution may vary depending on the neighborhood socioeconomic status. A 2022 study that followed 12,000 participants for more than 50 years showed that living in a lower neighborhood socioeconomic status could increase the likelihood of cognitive impairment. A 2022 study with Chinese Health and Retirement Longitudinal Study between 2011 and 2015 found small effect of air pollution on cognitive decline.
If you would like to learn more about the effects of air pollution on your health, please feel free to visit the National Institute of Environmental Health Sciences’s web page.
What Can We Do to Prevent/Mitigate Exposure to Air Pollution?
In order to check the air quality in your area, you can utilize tools like the EPA’s air pollution monitor, AirNow. You can stay indoors, where the central air system has a higher quality air filters such as High Efficiency Particulate Air (HEPA) filter.
- Use electrostatic air cleaner: it works with static electricity to charge particles inside the air purifier, which can attract those charged particles to the sides of the internal filtration system and remove from the air.
- Use portable filter-based air cleaners: these air cleaners can remove bacteria, viruses, and air pollutants. New York Times has a great list of air cleaner recommendations.
- Avoid outdoors activities: in order to reduce the chance of inhaling air pollutants, avoid rigorous outdoors activities such as running and biking. Also, try to avoid traffic, which may have higher concentration of air pollutants.
- Wear KN/N95 masks: wearing masks can reduce air pollutant inhalation like carbon monoxide.
A 2020 study showed that consuming omega-3-rich foods can have protective effect against brain shrinkage among older women.
Summary
We looked into what are components of air pollution. We then explored what could be health effects of inhaling air pollutants. Although it is unfortunate that there is limited activities we can do to immediately reduce the air pollution, we can take steps to prevent deteriorative health effects. If you have health concerns, please contant your physicians for concrete evidence and detail of your care.
Disclaimer: This web post is for information purposes. If you have medical needs, please contact your primary care physician
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