Exposure to higher concentrations of air pollution has been linked to an increased risk of developing long term, multiple physical and mental health issues, new research has indicated.

In the largest study of its kind worldwide, researchers examined the data of more than 364,000 people and say their findings “warrant further research in this area”.

People exposed to greater levels of traffic-related air pollution were found to be at an elevated risk of at least two long term health conditions, with the strongest links found for co-occurring neurological, respiratory, cardiovascular and mental health conditions such as depression and anxiety.

The study was led by researchers from Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London and was funded by National Institute for Health and Care Research (NIHR), Maudsley Biomedical Research Centre and NIHR Applied Research Collaboration (ARC) South London.

The study’s first author, Dr Amy Ronaldson, a Research Associate at Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, said: “People with more than one long-term health condition have a lower quality of life and greater dependence on the healthcare system.

“Our NIHR funded research has indicated that those people that live in areas of higher traffic-related air pollution are at greater risk of having multiple health conditions. The study does not prove that air pollution causes multimorbidity, but it does warrant further research in this area. It could be that simple measures to reduce traffic levels could potentially improve lives and lessen the pressure on our healthcare systems.”

Study participants who were exposed to higher levels of fine particulate matter had an increased risk of 21% of having two or more co-occurring conditions.

For those people exposed to higher levels of nitrogen dioxide, they had a 20% increased risk of having two or more co-occurring conditions.

Senior author Dr Ioannis Bakolis, Reader at IoPPN, King’s College London, said: “How air pollution affects multiple organs and systems at the same time is not yet fully understood, but there is some evidence that mechanisms such as inflammation, oxidative stress and immune activation could be triggered by air particulates, which can cause damage to the brain, heart, blood, lungs and gut.

“Our study suggests that it could be through shared mechanisms that air pollution negatively impacts several body systems and increases the likelihood of people developing multiple long term health conditions. More research is needed to understand just how air pollution affects the different bodily systems, but it may be that tackling air pollution could help prevent and alleviate the debilitating impact of multiple long-term health conditions.”

Read the study in the journal Frontiers in Public Health.

Major study shows exposure to air pollution puts people at greater risk of multiple health conditions