Growing up in air-polluted areas linked to mental health issues
People who spend their childhood in areas with high levels of air pollution may be more likely to later develop mental disorders, research suggests. Air pollution has become a matter of growing concern as an increasing number of studies have found links to conditions ranging from asthma to dementia and various types of cancer. There are also signs it may take a toll on mental health. Research published in January found that children growing up in the more polluted areas of London were more likely to have depression by the age of 18 than those growing up in areas with cleaner air. But a study by researchers in the US and Denmark has suggested a link between air pollution and an increased risk of mental health problems, including bipolar disorder, schizophrenia and personality disorders.
Between 1% and 2% of the UK population have bipolar disorder in their lifetime, with similar figures for schizophrenia. It is estimated that about 5% of people in the UK have a personality disorder at any one time. Prof Andrey Rzhetsky, a co-author of the research at the University of Chicago, said the team carried out their work after finding that genetics did not fully explain why some people experienced these conditions and others do not.
Writing in the journal PLOS Biology, Rzhetsky and colleagues explained how they used a rather crude approach when they first examined possible links to air pollution. Insurance data for 151 million individuals collected between 2003 and 2013 was used to explore the rates of particular mental disorders in counties across the US. This was then analysed alongside the average level of air pollution in each county. The team found the rate for bipolar disorder was 27% higher for counties in the bottom seventh for air quality compared with those in the top seventh (with the best air quality), once factors including age, sex, poverty levels in the county and average income were taken into account. A tentative link was also seen for depression and air pollution. However, this analysis was based on average air pollution levels over very large areas. What’s more, the rates of psychiatric conditions may not reflect the situation for low-income individuals who may be less likely to have insurance. The team then looked at air pollution data from Denmark, which was collected on a scale of 1 sq km.
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