Suicide by gases in England and Wales 2001-2011: evidence of the emergence of new methods of suicide.

BACKGROUND: Increases in suicide deaths by gassing, particularly carbon monoxide poisoning from burning barbecue charcoal, have occurred in many parts of East Asia and resulted in rises in overall suicide rates in some countries. Recent trends in gas poisoning suicides outside Asia have received little attention. METHODS: We analysed suicides by gassing in England and Wales (2001-2011) using national suicide mortality data enhanced by free text searching of information sent by coroners to the Office for National Statistics (ONS). We conducted specific searches for suicides involving barbecue charcoal gas, helium, and hydrogen sulphide. We analysed coroners' records of eight people who used helium as a method of suicide, identified from systematic searches of the records of four coroners. RESULTS: Gassing accounted for 5.2% of suicide deaths in England and Wales during 2001-2011. The number of gas suicides declined from 368 in 2001 to 174 by 2011 (a 53% reduction). The fall was due to a decline in deaths involving car exhaust and other sources of carbon monoxide. There was a rapid rise in deaths due to helium inhalation over the period, from five deaths in the two year period 2001-2002 to 89 in 2010-2011 (a 17-fold increase). There were small rises in deaths involving hydrogen sulphide (0 cases in 2001-2002 versus 14 cases in 2010-2011) and barbecue charcoal gas (1 case in 2001-2002 versus 11 cases in 2010-2011). Compared to individuals using other methods, those suicides adopting new types of gas for suicide were generally younger and from more affluent socioeconomic groups. The corones' records of four of the eight individuals dying by helium inhalation whose records were reviewed showed evidence of Internet involvement in their choice of method. LIMITATIONS: We were not able to identify the source of carbon monoxide (car exhaust or barbecue charcoal) for over 50% of cases. CONCLUSION: Increases in helium inhalation as a method of suicide have partially offset recent decreases in suicide by the use of car exhaust. Public health measures are urgently needed to prevent a potential epidemic rise in the use of helium similar to the recent rises in charcoal burning suicides in East Asia.