Depression and suicide risk linked to air pollution

People exposed to higher levels of air pollution are more likely to experience depression or die by suicide, finds a new analysis led by UCL. The first systematic review and meta-analysis of evidence connecting air pollution and a range of mental health problems, published in Environmental Health Perspectives , reviewed study data from 16 countries. The researchers found that, if the relationship with depression reported in some of these studies is causal, then reducing global average exposure to fine particulate matter (PM_2.5) air pollution from 44 micrograms per metre cubed (µg/m³)* to 25µg/m³ could result in a 15% reduction in depression risk worldwide. The World Health Organization guidelines recommend that fine particulate matter pollution - small airborne particles that can include dust and soot - should be kept under 10µg/m³.** "We already know that air pollution is bad for people's health, with numerous physical health risks ranging from heart and lung disease to stroke and a higher risk of dementia," said the study's lead author, Dr Isobel Braithwaite (UCL Psychiatry and UCL Institute of Health Informatics). "Here, we're showing that air pollution could be causing substantial harm to our mental health as well, making the case for cleaning up the air we breathe even more urgent." The research team searched for studies that had investigated the association between particulate matter pollution and five different adverse mental health outcomes in adults.