ISLAMABAD             -           People exposed to higher levels of air pollution are more likely to experience depression or commit suicide, researchers have found.

The systematic review and meta-analysis of evidence connecting air pollution and a range of mental health problems, published in the journal Environmental Health Perspectives, reviewed study data from 16 countries.

“Our findings correspond with other studies that have come out this year, with further evidence in young people and in other mental health conditions,” said the study’s senior author, Joseph Hayes from the University College London.

“While we cannot yet say that this relationship is causal, the evidence is highly suggestive that air pollution itself increases the risk of adverse mental health outcomes,” Hayes said.

The WHO guidelines recommend that fine particulate matter pollution - small airborne particles that can include dust and soot - should be kept under 10µg/m3.

For the findings, the research team searched for studies that had investigated the association between particulate matter pollution and five different adverse mental health outcomes in adults.

They identified 25 studies that fitted their criteria, nine of which were included in the primary analyses.

Five studies looking at long-term particulate matter exposure and depression were included in one meta-analysis.

By pooling the results, they found that a 10µg/m3 (microgram per metre cubed) increase in the average level of fine particulate matter (PM2.5) air pollution people were exposed to over long periods was associated with an approximately 10 per cent increase in their odds of depression.

The researchers said that the evidence was particularly strong for the suicide risk link, but the effect was smaller than for depression (an increase in suicide risk of two per cent for each 10µg/m3 increase in the average coarse particulate pollution level over a three-day period).