Air pollution may trigger depression in children

By Stephen Beech via SWNS

Air pollution may trigger depression in children, suggests a new study.

Exposure to ozone from air pollution has been linked to an increase in depressive symptoms among adolescents - even in areas that meet air quality standards, say scientists.

Ozone is a gas that is produced when various pollutants from motor vehicle exhaust, power plants and other sources react to sunlight.

Higher ozone levels have been previously linked to several physical ailments - including asthma, respiratory viruses and premature death from respiratory causes.

The new study is the first to link ozone levels to the development of depression symptoms in adolescents over time. The symptoms may include persistent feelings of sadness or hopelessness, difficulty with concentration, sleep disturbances and suicidal thoughts.

Lead researcher Dr. Erika Manczak, an assistant professor of psychology at the University of Denver said: "I think our findings really speak to the importance of considering air pollution’s impact on mental health in addition to physical health."

The researchers analyzed data from a previous study about early life stress with 213 participants, aged nine to 13-years-old, in the San Francisco Bay area.

The team compared data about the youngsters’ mental health over a four-year period with Census tracts for their home addresses and air quality data for those tracts from the California Environmental Protection Agency.

Those who lived in areas with relatively higher ozone levels showed "significant" increases in depressive symptoms over time, even though the ozone levels in their neighborhoods didn’t exceed state or national air quality standards.

Dr. Manczak pointed out that their findings, published in the journal Developmental Psychology, weren’t affected by the participants’ sex, age, race, household income, parental education or socio-economic characteristics of their neighborhoods.

She said: “It was surprising that the average level of ozone was fairly low even in the communities with relatively higher ozone exposure.

“This really underscores the fact that even low levels of ozone exposure have potentially harmful effects.”

Dr. Manczak explained that ozone and other components of air pollution can contribute to high levels of inflammation in the body, which has been linked to the onset and development of depression. Youngsters may be especially sensitive to these effects because they spend more time outdoors.

She said the findings are correlational so it can’t be proven that ozone levels caused an increase in depressive symptoms, only that there is a link between them. It’s also possible that other components of air pollution besides ozone could be a factor.

Dr. Manczak said communities should consider ways to reduce ozone exposure, such as holding youth sporting events indoors when necessary and limiting driving during peak hours of air pollution alerts, while investment in clean and renewable energy sources that reduce air pollution could also be helpful.

She added: “I believe air quality standards should be stricter, and we should have tighter regulations on industries that contribute to pollution.

“Our findings and other studies suggest that even low levels of ozone exposure can pose potentially serious risks to both physical and mental health.”