Spending just one hour breathing in polluted air can change the way your brain and lungs function, a new study has found.
Air pollution, specifically pollutants called particulate matter (PM), has been linked to a multitude of diseases, including asthma and several forms of cancer.
In new research, healthy adults were exposed for 60 minutes to five different air types: clean air, limonene SOA (a citrus fragrance commonly used in cleaning products), diesel exhaust, woodsmoke and cooking emissions.
After an hour, the volunteers had a four-hour break from exposure before researchers tested their lung function, working memory, attention, emotion processing, psychomotor control (the time it takes the brain to receive sensory information) and motor function.
The greatest respiratory impact was seen among people exposed to limonene, followed by woodsmoke, diesel exhaust and cooking emissions.
When it came to cognition, diesel exhaust showed the strongest signs of impairing executive function, which is responsible for planning, focused attention and emotional regulation.
This may be because nitrogen oxides in the pollutant can alter blood flow to the brain, impairing day-to-day function.
Though participants were only around pollutants for an hour, the researchers warned repeated exposure could lead to permanent cognitive issues and health risks such as cancer.
Researchers in the UK found just an hour of pollution exposure may worsen lung and cognitive function (file photo)
‘This unique clinical study highlighted the importance of the lung-brain axis in brain responses to air pollution,’ Dr Thomas Faherty, lead study author and post-doctoral researcher at the University of Birmingham in the UK, said.
‘Safely exposing the same individuals to multiple real-world pollution mixtures allowed us to detect differences between pollutants, demonstrating the value of this approach for further pollution-dementia research.’
Particulate matter is made up of microscopic particles from sources like car exhaust, power plants, wildfires and fuel burning. These particles are so tiny that they can penetrate deep into lung tissue and even enter the bloodstream.
In the bloodstream, particulate matter creates inflammation, constricts blood vessels – raising blood pressure and promoting artery-narrowing plaque – and triggers oxidative stress, damaging cells, mitochondria and DNA from head to toe.
Past research has tied a type of particulate matter called fine particulate matter (PM2.5) to dementia. In a February study, researchers found that for every small increase in PM2.5, Alzheimer’s disease risk rose by nearly nine percent.
Experts estimate about 150 million Americans are regularly exposed to environmental pollution.
In the new study from the University of Birmingham, researchers recruited 15 healthy adults over the age of 50. The participants did not have dementia but did have a family history of the disease, which increases their overall risk.
The average participant age was 60, and 62 percent were men. All were white.
While participants were educated on the four pollution exposure mixtures, along with clean air, they were unaware of the order in which they were exposed. After each exposure, researchers asked participants to identify which of the five conditions they believe they experienced with a confidence rating between 1 (not at all confident) and 5 (completely confident).
Experts estimate about 150 million Americans are regularly exposed to environmental pollution from sources like car exhaust and factories (file photo)
The team found limonene aerosol exposure reduced lung function by 3.4 percent, followed closely by 2.6 percent in woodsmoke exposure.
Diesel exhaust exposure also led to small reductions in executive function, which can be measured with tasks like copying shapes and word recall.
‘Even though the pollution mixtures were adjusted to contain similar levels of particulate matter, which is how we currently measure air pollution, we didn’t see a single, uniform response,’ Gordon McFiggans, study author and professor of atmospheric sciences at the University of Manchester in the UK, said.
‘Instead, each pollution source produced its own pattern of short-term changes in the lungs and the brain. This tells us that the body doesn’t respond to all air pollution in the same way, the source and composition of the pollution really matter.’
The team noted more research is needed on long-term effects of exposure to different types of particulate matter that may help drive legislation and other measures to protect vulnerable populations.