A study published in Environmental Science and Ecotechnology has revealed a strong connection between long-term air pollution exposure and an increased risk of depression.
This study was based on data from the China Health and Retirement Longitudinal Study which focusses on the Chinese population over 45 years old.
The cohort was made up of 12,389 participants using data from 2013 to 2020.
A 10-item questionnaire from The Center for Epidemiologic Studies-Depression was used to measures the severity of depressive symptoms among the cohort, while concentrations of CO, O3, NO2, SO2, PM10, and PM2.5 were obtained from the China High Air Pollutants datasets.
The primarily goal of the research was to evaluate any association between depression and exposure to single, dual, and multiple air pollutants, and identifying the primary pollutants that contribute to depressive symptoms.
The team found a particularly strong association between sulfur dioxide (SO₂) exposure and the risk of depression, with PM2.5 and carbon monoxide (CO) also linked to depressive symptoms. SO2 was described as ‘the primary and stable contributor to the increased risk of depressive symptoms, both in individual and combined exposures.’
The impact of these pollutants was compounded when they were both or all present in the air, with each quantile rise in combined air pollution, the risk of depression increased by 38%.
Only ozone (o3) was found to have no association with the risk of depression although the link with NO2 was so slight as to be deemed insignificant.
It was also noted that those members of the cohort who developed depressive symptoms were more likely to be female, live in rural areas, be single or separated/divorced, be nonsmokers, be nondrinkers, show less engagement in social activities, and have lower educational levels.
The researchers noted: ‘Our findings underscore the critical need for integrated air quality management to improve both physical and mental health. Targeting SO₂ and other key pollutants could significantly alleviate the public health burden of depression, particularly among vulnerable populations like middle-aged and older adults.’
The full research can be read here.
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