A recent study reveals that inhaling polluted air for just one hour can affect brain and lung function, even in healthy people.
Air pollution, especially fine particulate matter (PM), is a major factor associated with serious health problems such as asthma and some types of cancer, in addition to its increasing association with potential effects on cognitive abilities.
In the study, researchers exposed a group of adults over the age of 50, all of whom had a family history of dementia but did not have it, to five different types of air for 60 minutes, including: clean air, limonene gas (an acid-smelling compound used in cleaning products), diesel exhaust, wood-burning smoke, and cooking emissions.
The average age of the participants was 60 years, and the majority of the sample were men and white people.
After the exposure period ended, the participants were given a four-hour rest, and then underwent tests to measure lung function, attention, working memory, emotional processing, motor response speed, and executive brain functions.
The results showed that the strongest effect on the respiratory system was in those exposed to limonene gas, followed by wood smoke, then diesel exhaust, and finally cooking emissions, with slight decreases in lung function recorded in some groups.
At the brain level, diesel exhaust was found to have the greatest impact on executive functions, which are responsible for planning, concentration, and emotional control.
Researchers suggest that these effects may be due to the fact that some pollutants, such as nitrogen oxides, can affect blood flow to the brain, which in turn affects its efficiency.
Although the exposure lasted for a short period of no more than one hour, the researchers warned that repeated exposure to these pollutants could, over time, lead to more serious health effects, including possible cognitive problems.
Dr. Thomas Faherty, lead author of the study and a postdoctoral researcher at the University of Birmingham, said: "This study highlights the importance of the lung-brain relationship in responding to air pollution."
He added: "Providing participants with safe exposure to a mixture of realistic pollutants enabled us to observe the different effects of each type, which shows that the source of the pollution and its chemical composition are important factors in determining its effect on the body."
Particulate matter is formed from multiple sources such as car exhaust, power plants, forest fires and fuel burning, and is characterized by its small size which allows it to reach deep into the lungs and may enter the bloodstream.
If it enters the body, it may cause inflammation, affect blood vessels, raise blood pressure, and increase the accumulation of deposits inside the arteries. It may also lead to cell damage as a result of oxidative stress.
Previous research has linked fine particulate matter (PM2.5) to an increased risk of dementia, with one study showing that a slight increase in its concentration may raise the risk of Alzheimer's disease by about 9%.
The researchers stressed the need for more research on the long-term effects of air pollution of all kinds, with the aim of improving understanding of the relationship between it and public health, and developing more effective policies to protect the most vulnerable groups.
