Effects of Weather on Incidence of Attempted Suicide by Carbon Monoxide Poisoning

This study sought to determine the effects of weather & time of year on suicide attempts by carbon monoxide poisoning. Cases of patients in western Washington State referred to a regional hyperbaric oxygen treatment centre from 1981-1995 were reviewed retrospectively. The study population consisted of 264 patients attempting suicide by carbon monoxide poisoning on 251 days of the 15-year period. Mean & total precipitation in the preceding 7 days strongly correlated with the attempted suicide rate. A decrease in minimum daily temperature also correlated with attempted suicide rates. No other weather variables showed significant correlations with dates of carbon monoxide suicide attempts. February, March, & October were seen to be separate factors related to a higher incidence of attempted suicide by carbon monoxide poisoning. (20 refs.)