Scientists think they have found a link between air pollution and our mental health

Air pollution stifles the lungs and shortens lives, but is also linked to a higher risk of mental illness, researchers said Tuesday in a study based on health data from millions of cancer patients. United States and Denmark.

People exposed to poor-quality air in both countries were more likely to be diagnosed with bipolar disorder or depression, the study revealed, although critics argued that it was defective and stated that more research was needed to draw definitive conclusions.

"There are many known triggers (for mental illnesses) but pollution is a new direction," told the Thomson Reuters Foundation, Andrey Rzhetsky, head of the study, from the University of Chicago.

"Research on dogs and rodents has shown that air pollution can enter the brain and cause inflammation that causes symptoms resembling depression." It is quite possible that the same thing will happen in the home. # 39; man. "

The World Health Organization (WHO) estimates that air pollution kills 7 million people each year, 13 per minute, more than war, murder, tuberculosis, HIV, AIDS and malaria.

According to a study released earlier this year by the US Health Effects Institute, it could reduce the life expectancy of children born today by an average of 20 months.

Growing concerns about this issue have seen cities like Paris, Bogotá and Jakarta experience car-free days.

But while the impact of pollution on physical health is well known, links to mental illness have been less explored.

The researchers compared health data and exposure to local pollution among 151 million US residents and 1.4 million Danish patients in the study published in PLOS Biology.

For Danish patients, they compared mental health with exposure to air pollution up to the age of 10, while in the US, they looked at levels pollution in real time.

The children's exposure has been linked to an increase of more than twice the schizophrenia in Danish patients, said the researchers, as well as to higher rates of personality disorders, depression and depression. bipolar disorders.

Data from the United States also showed that poor air quality was associated with higher levels of bipolarity and depression, but did not reveal any correlation with several other conditions, including schizophrenia, epilepsy and Parkinson's disease.

However, the study has proved controversial.

A critical commentary by Stanford professor John Ioannidis, published in parallel with the study, indicates that it raises an "intriguing possibility" that air pollution may cause mental illness, but has not made it possible to do so. evidence.

"Despite analyzes involving large datasets, the available evidence has significant gaps and a long series of potential biases may invalidate the observed associations," he wrote.