Cut air pollution to benefit mental health, too

By Erika Manczak, Colorado Sun, Feb 4, 2021. If safeguards are not reinstated — and, ideally, tightened — we risk repeating horrors we’ve already seen when oversight is eliminated or compromised.

Haze and smog shroud the mountain view behind the Denver City and County Building, as seen on Nov. 5, 2019. The state Department of Public Health and Environment issued an “action day” advisory for poor visibility for the day, but the overall air quality was labeled as “moderate.” (John Ingold, The Colorado Sun)

During his first two weeks in office, President Joe Biden has signed executive orders to roll back some of the more than 125 environmental and climate policy measures put in place during the Trump administration. This commitment is significant because reducing pollution exposure will not only promote better physical health, it will also benefit mental health.  

As a clinical psychologist and researcher, I’ve shown that exposure to even low levels of air and water pollution predict mental health symptoms in teenagers. For example, in one study, my colleagues and I found that teens who lived in neighborhoods with higher levels of lead, arsenic or nitrates in their community drinking water showed significantly higher levels of depressive symptoms two years later than did teenagers with better drinking water.  Notably, the levels of these contaminants in our sample were all deemed acceptable by 2017 safety thresholds, suggesting we need much more stringent — not less stringent — guidelines. 

As well, our data examining air pollution has found that living in a neighborhood with higher levels of ozone predicted sharper increases in participants’ anxiety and depressive symptoms across a five-year period compared to living in lower ozone areas. 

Because more disadvantaged neighborhoods are generally more likely to have higher pollution exposure, we also confirmed that poverty, educational attainment, and other life stressors did not account for these findings. 

Furthermore, preliminary work in my lab suggests that these associations can play out quickly: a week of worse air quality can predict higher levels of anxiety symptoms in young adults, even after adjusting for pre-existing symptoms of generalized anxiety disorder. This is consistent with findings by other research groups that higher rate of suicide and more psychiatric hospitalizations track seasonal variations in ozone. 

One way these pollutants may lead to mental health symptoms is by acting on some of the same biological processes that link pollution to physical disease. For example, once ingested or inhaled, these molecules can contribute to activation of parts of the immune system that contribute to systemic inflammation and can cross the blood-brain barrier to potentially change brain development or functioning

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To this end, higher levels of inflammation are associated not only with cardiovascular disease and asthma, but also depressive and other psychiatric symptoms.  Of course, most individuals are unaware of their daily ozone or water contaminant exposure, making these processes particularly insidious.

EPA rollbacks can also result in the destruction of natural spaces, which can similarly take psychological tolls, but through different mechanisms. Substantial research attests to the fact that access to green space can lower physiological and emotional stress processes. Air pollution that obscures beautiful vistas or manufacturing runoff that spoils biodiverse landscapes can make these opportunities much less enticing. 

Furthermore, hazy air and contaminated soil can force more people inside and reduce opportunities for physical exercise, which can also affect mental health.

If safeguards are not reinstated — and, ideally, tightened — we risk repeating horrors we’ve already seen when oversight is eliminated or compromised for the sake of illusory economic gains. For example, the water crisis in Flint, Michigan, has contributed to substantial social and emotional challenges for its residents, including higher levels of cognitive impairment and distress. 

Compounding this, the experience has understandably instilled a distrust of public institutions that can thwart efforts to connect residents with therapy and supports. Countless other American communities have their own harrowing accounts of spoiled landscapes, toxic air, and contaminated water that we fail to recognize.

Especially now, as Americans face unprecedented challenges, it is critical to do whatever we can to foster better mental health. To promote lasting and shared change we must turn to our national government. Recommitting to reducing pollution is a good place to start. 


Erika Manczak is an assistant professor of psychology at the University of Denver.