New research involving almost 364,000 English citizens found that traffic-related air pollution raises the likelihood of several long-term physical and mental health disorders.
This research, led by King’s College London’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN), is the world’s most extensive study on air pollution and long-term health concerns.
The UK’s air quality has been steadily deteriorating in recent years due to increased population and higher road traffic levels. This has led to a higher concentration of pollutants in the air, with the UK exceeding legal limits for pollutants such as nitrogen dioxide contributing to the increased risk of various health disorders.
The study, published in Frontiers in Public Health, found that high levels of traffic-related PM2.5 and NO2 raised the risk of at least two long-term health disorders. Co-occurring conditions such as neurological, pulmonary, cardiovascular, and mental health disorders, including anxiety and depressive disorders, had the highest connections.
Multimorbidity, as defined as having two or more medical conditions, affects 27% of UK primary care individuals. It increases primary and secondary care usage and expenditures, but its link with air pollution has recently been explored in the UK.
Dr. Amy Ronaldson, a Research Associate at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, and the first author of the study, said: “People with more than one long-term health problem have a worse quality of life and higher dependency on the healthcare system.”
“Our NIHR-funded research found that traffic-related air pollution increases the likelihood of various health problems. Air pollution does not induce multimorbidity. However, the findings warrant more study. Traffic reduction may enhance lives and minimize healthcare system strain.”
Researchers examined anonymized genetic, lifestyle, and health data from half a million UK residents aged 40–69 from UK Biobank, a large-scale biological database, and research resource. They analyzed thirty-six physical and five mental health chronic diseases. The study defined multimorbidity as having two or more of those conditions.
UK Biobank’s 2010 physical and mental health data were connected to air pollution estimates at members’ homes.
They found that greater fine particulate matter concentrations (over 10μg/m3) were associated with a 21% higher chance of two or more co-occurring diseases.
Participants exposed to NO2 values over 30μg/m3 had a 20% higher probability of having two or more co-occurring conditions than those exposed to NO2 below 20μg/m3.
PM2.5 and NO2 exposure worsened co-occurring symptoms in those with multiple conditions.
Dr. Ioannis Bakolis, Reader at IoPPN, King’s College London, and senior author of the study, 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 damage the brain, heart, blood, lungs, and gut.
“Our work reveals that air pollution negatively influences various physiological systems and raises the risk of multiple long-term health disorders through standard processes. Air pollution may prevent and alleviate many long-term health disorders, but more study is needed to understand how it impacts the body’s systems.”
Asthma, COPD, atrial fibrillation, coronary heart disease, and heart failure were the greatest connections, although neurological and common mental illnesses were also linked (stroke, substance abuse, depression, and anxiety).
NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, and NIHR Applied Research Collaboration South London sponsored this work.