Carbon Monoxide Poisoning - Epidemiology - Suicide

Suicide

Before the 1960s most domestic gas supply in the United Kingdom was coal gas (alternatively known as town gas), which in its unburned form contained high levels of carbon monoxide. Carbon monoxide poisoning by intentionally inhaling coal gas was a common suicide method, accounting for nearly half of all suicides in the United Kingdom in the late 1950s. After the British government phased out coal gas in favor of natural gas in the 1960s, the suicide rate in Britain fell by almost a third and has not risen since. The use of coal gas as a suicide method has declined as most domestic gas supply worldwide is now natural gas, which lacks carbon monoxide. Until the invention of catalytic converters, suicide has been committed by inhaling the exhaust fumes of a running car engine, particularly in an enclosed space such as a garage. Before 1975, motor car exhaust contained 4–10% carbon monoxide, but newer cars have catalytic converters that eliminate over 99% of the carbon monoxide produced. However even cars with catalytic converters can produce substantial amounts of carbon monoxide if an idling car is left in an enclosed space such as a closed garage.

As carbon monoxide poisoning via car exhaust has become less of a suicide option, there has been an increase in new methods of carbon monoxide poisoning such as burning charcoal, or fossil fuels, or by combining formic acid and sulfuric acid, within a confined space. Such incidents have occurred mostly in connection with group suicide pacts in Asian countries such as Japan, Taiwan, and Hong Kong, but are starting to occur in western countries as well, such as the 2007 suicide of Boston lead singer Brad Delp.