Long-Term Exposure to Air Pollutants Linked to Depression and Anxiety

In an article published in JAMA Psychiatry, researchers acknowledged the potential risks associated with air pollution, linking long-term exposure to higher rates of depression and anxiety. Researchers in the study recognize the many impacts of environmental pollution on human health. Before this study was conducted, there was little evidence of the links between exposure and the incidence of depression and anxiety.

The prospective population-based cohort study used data from the UK Biobank, which recruited participants from March 2006 to October 2010. The data was analyzed between May and October 2022.

Researchers focused on long-term exposure to low levels of pollutants. They looked at multiple kinds of air pollutants: particulate matter (PM) 2.5 μm or less (PM₂.₅), PM that is 2.5–10 μm (PM₂.₅₋₁₀), nitrogen dioxide, and nitric oxide.

Furthermore, depression and anxiety were determined using the tenth revision of the International Statistical Classification of Diseases and Related Health Problems.

According to the researchers, the average concentration of PM₂.₅ was 9.9 μg/m³. Furthermore, the average concentrations of PM₂.₅₋₁₀, nitrogen dioxide, and nitric oxide were 6.1 μg/m³, 26 1 μg/m³, and 15.9 1 μg/m³, respectively.

They determined that those in the highest quartile of exposure were 11% more likely to experience anxiety than those in the lowest quartile. Furthermore, those with higher exposure were roughly 16% more likely to experience depression than those with lower exposure.

Using the data collected, the researchers generated curves on the incidence of depression and anxiety and the long-term estimated exposure to pollutants. However, the curves concluded that the relationship was not linear between exposure and depression or anxiety. The association was more significant at lower concentrations than at higher concentrations, implying some threshold of impact after a certain amount of exposure.

Researchers in the study concluded, “Study results suggest that estimates of long-term exposure to multiple air pollutants was associated with increased risk of depression and anxiety. The nonlinear associations may have important implications for policymaking in air pollution control. Reductions in joint exposure to multiple air pollutants may alleviate the disease burden of depression and anxiety.”

Because the effects of pollution and environmental toxins have been pervasive in nearly every aspect of healthcare, it is evident that environmental health will have long-lasting impacts on human health. Data like that reported in this study provides strong evidence in favor of more environmental protection protocols.