Consider the big picture of air quality
The Italian study is especially timely “given our evolving and emerging understanding of environmental risk factors for acute and chronic diseases, which we must first understand before we can address,” said Eileen Barrett, MD, of the University of New Mexico, Albuquerque, in an interview.
Dr. Eileen Barrett
“I am largely surprised about the findings, as most physicians aren’t studying ambient air quality and risk for autoimmune disease,” said Dr. Barrett. “More often we think of air quality when we think of risk for respiratory diseases than autoimmune diseases, per se,” she said.
“There are several take-home messages from this study,” said Dr. Barrett. “The first is that we need more research to understand the consequences of air pollutants on health. Second, this study reminds us to think broadly about how air quality and our environment can affect health. And third, all clinicians should be committed to promoting science that can improve public health and reduce death and disability,” she emphasized.
The findings do not specifically reflect associations between pollution and other conditions such as chronic obstructive pulmonary disease and asthma although previous studies have shown an association between asthma and COPD exacerbations and air pollution, Dr. Barrett said.
“Further research will be needed to confirm the associations reported in this study,” Dr. Barrett said.
More research in other countries, including research related to other autoimmune diseases, and with other datasets on population and community level risks from poor air quality, would be helpful, and that information could be used to advise smart public policy, Dr. Barrett added.
Air pollution’s mental health impact
Air pollution’s effects extend beyond physical to the psychological, a new study of depression in teenagers showed. This study was published in Developmental Psychology.
Previous research on the environmental factors associated with depressive symptoms in teens has focused mainly on individual and family level contributors; the impact of the physical environment has not been well studied, the investigators, Erika M. Manczak, PhD, of the University of Denver and colleagues, wrote.
In their paper, the authors found a significant impact of neighborhood ozone exposure on the trajectory of depressive symptoms in teens over a 4-year period.
“Given that inhaling pollution activates biological pathways implicated in the development of depression, including immune, cardiovascular, and neurodevelopmental processes, exposure to ambient air pollution may influence the development and/or trajectory of depressive symptoms in youth,” they said.
The researchers recruited 213 adolescents in the San Francisco Bay area through local advertisements. The participants were aged 9-13 years at baseline, with an average age of 11 years. A total of 121 were female, 47% were white, 8.5% were African American, 12.3% were Asian, 10.4% were nonwhite Latin, and 21.7% were biracial or another ethnicity. The participants self-reported depressive symptoms and other psychopathology symptoms up to three times during the study period. Ozone exposure was calculated based on home addresses.
After controlling for other personal, family, and neighborhood variables, the researchers found that higher levels of ozone exposure were significantly associated with increased depressive symptoms over time, and the slope of trajectory of depressive symptoms became steeper as the ozone levels increased (P less than .001). Ozone did not significantly predict the trajectory of any other psychopathology symptoms.
“The results of this study provide preliminary support for the possibility that ozone is an overlooked contributor to the development or course of youth depressive symptoms,” the researchers wrote in their discussion.
“Interestingly, the association between ozone and symptom trajectories as measured by Anxious/Depressed subscale of the [Youth Self-Report] was not as strong as it was for the [Children’s Depression Inventory-Short Version] or Withdrawn/Depressed scales, suggesting that associations are more robust for behavioral withdrawal symptoms of depression than for other types of symptoms,” they noted.
The study findings were limited by the use of self-reports and by the inability of the study design to show causality, the researchers said. Other limitations include the use of average assessments of ozone that are less precise, lack of assessment of biological pathways for risk, lack of formal psychiatric diagnoses, and the small geographic region included in the study, they said.
However, the results provide preliminary evidence that ozone exposure is a potential contributing factor to depressive symptoms in youth, and serve as a jumping-off point for future research, they noted. Future studies should address changes in systemic inflammation, neurodevelopment, or stress reactivity, as well as concurrent psychosocial or biological factors, and temporal associations between air pollution and mental health symptoms, they concluded.