[Suicide due to carbon monoxide poisoning-trends and preventive measures].

To lessen the number of suicide is a nationwide problem in Japan. Recently, suicide due to carbon monoxide poisoning with charcoal burning is increased. The information on this method seems to have spread via suicide-related websites. In addition, there are concerns about drugs and illegal substances that can be bought obtained via the internet. In Japan, the establishment of a voluntary internet guideline in 2005 was effective to save the lives of the persons with suicidal ideations.