Motor vehicle exhaust gas suicide in Victoria, Australia 1998-2002

Motor vehicle exhaust gas suicide (MVEGS) is the second most frequent method of suicide in Victoria, Australia. It is a highly lethal method of suicide with 1.5 deaths for every hospital admission. Australian regulations require all vehicles manufactured since 1998 to have a maximum carbon monoxide exhaust emission level of 2.1 g/km, reduced from the previous level of 9.6 g/km. Information surrounding all Victorian MVEGS between 1998-2002 was analyzed to determine whether suicides occurred in vehicles with the lower emission levels. Between 1998-2002, 607 suicides by this means were recorded while just 393 hospital admissions were recorded for the same period. Mean carboxyhaemoglobin levels were significantly lower in fatalities using vehicles manufactured from 1998, however suicide still occurred in these vehicles (n = 25). The extent to which the new regulations contributed to the relatively low rate of suicide in vehicles less than 5 years old compared to their frequency in the fleet remains unknown. Based on international experience and the age of the Victorian vehicle fleet, it may take well over a decade until substantial decreases in MVEGS are observed in the absence of active preventive measures.