Breathing in polluted air is linked to an increased risk for suicide, particularly among middle-aged men, according to researchers at the University of Utah. The study is adding to the small, but growing body of research linking air pollution exposure to suicide.
For the study, the researchers highlight the chemical and meteorological variables that are risk factors for suicide and examine how these factors play out among different genders and age groups. The findings build on their research from 2014, when they discovered that fine particulates and nitrogen dioxide in air pollution were linked with an increased risk for suicide.
In the latest study, the researchers found an increased risk of suicide tied to short-term exposure to nitrogen dioxide and fine particulate matter among Salt Lake City residents who died by suicide between 2000 to 2010. Specifically, men and people between the ages of 36 to 64 years experienced the highest risk of suicide following short-term air pollution exposure.
“We are not exactly sure why risk of suicide was higher in these two groups but suspect that it might be because these two groups were either exposed to higher levels of air pollution or that other additional factors make these two groups more susceptible to the effects of air pollution,” said investigator Amanda Bakian, Ph.D., an assistant professor of psychiatry at the University of Utah.
Looking at the records of more than 1,500 people who died by suicide in Salt Lake County between Jan. 1, 2000, and Dec. 31, 2010, Bakian found that the odds of completing suicide were 20 percent greater for people exposed to increased levels of nitrogen dioxide in the two to three days before their deaths.
Furthermore, residents exposed to high concentrations of fine particulate matter (PM2.5) in the two to three days before a suicide experienced five percent higher odds of suicide. The risk was highest during the spring and fall.
Men, in particular, experienced a 25 percent increase in the odds of suicide following short-term exposure to nitrogen dioxide and a six percent increase in the odds of suicide following short-term exposure to fine particulate matter.
Also, the odds of suicide in those between the ages of 36 to 64 rose by 20 percent following short-term exposure to nitrogen dioxide and seven percent following short-term exposure to fine particulate matter.
“As suicide risk was found to differ by age and gender, this suggests that vulnerability to suicide following air pollution exposure is not uniform across Salt Lake County residents and that some Salt Lake County residents are more vulnerable than others,” said Bakian.
“Our next step is to determine in more detail exactly what elements, such as genetic and sociodemographic factors. are responsible for increasing one’s vulnerability to suicide following air pollution exposure.”
Bakian emphasizes that the research doesn’t state that bad air causes suicide. Rather, it suggests that higher levels of pollution might interact with other factors to increase the risk for suicide, she noted.
In research published today in The American Journal of Epidemiology.
Source: University of Utah