Air pollution has long been linked to cardiovascular and respiratory diseases. Now, however, there is also a growing body of evidence that It also affects mental health.
Specifically, according to the results of a new study, published in JAMAthe journal of the American Medical Association, long-term exposure to high levels of air pollution increases risk of late-onset depression among older people.
To reach this conclusion, researchers from Harvard and Emory University examined data on nearly 9 million people with Medicare, the US government’s health insurance plan for people age 64 and older. Of these almost nine million, more than 1.52 million of them were diagnosed with depression during the study period of 2005 to 2016.
To conclude that pollution was a relevant factor in depression, pollution levels were mapped and compared to the addresses of Medicare patients. The pollutants they were exposed to were fine particles such as dust or smoke, nitrogen dioxide (mostly from road traffic) and ozone (cars, power plants and refineries).
Pollution could damage the brain
The more pollution, the more cases of anxiety and depression
Another second study published in the same journal has also obtained results along the same lines: long-term exposure to even low levels of air pollutants was associated with a higher incidence of depression and anxiety.
Researchers from Great Britain and China examined the relationship between prolonged exposure to multiple air pollutants and occurrences of depression and anxiety. They observed a group of about 390.000 personasmostly residents of Great Britain, for 11 years and found an increased risk of depression and anxiety, even when air pollution levels were below British air quality standards.
pollution also decreases the ability to learn
Pollution not only has effects on mental health, but on the brain in general, including cognition itself. According to research led by CREAL researchers and published in the journal Environmental Health Perspectivesair pollution generated by fine particles has a negative impact on human cognitiondiminishing the learning capacity.
The study followed 2,618 children from 39 schools in Barcelona with an average age of 8.5 years and found that traffic is the only source of fine particles that is associated with decreased cognitive development.
The exams carried out by the students included the evaluation of the work memory (the cognitive function of the brain that handles information temporarily), the superior working memory (which covers more complex processes), and lack of concentration.
In conclusion, this new body of evidence on the effects of pollution on the brain should encourage policies that improve air quality in cities, not only because of the health problems that have traditionally been associated with air pollution.