Automobile Exhaust as a Means of Suicide: An Experimental Study with a Proposed Model

Abstract

Experiments were conducted to investigate the concentration of carbon monoxide (CO) in a car cabin under suicide attempts with different vehicles and different start situations, and a mathematical model describing the concentration of CO in the cabin was constructed. Three cars were set up to donate the exhaust. The first vehicle didn't have any catalyst, the second one was equipped with a malfunctioning three-way catalyst, and the third car was equipped with a well-functioning three-way catalyst. The three different starting situations were cold, tepid and warm engine start, respectively. Measurements of the CO concentrations were made in both the cabin and in the exhaust pipe. Lethal concentrations were measured in the cabin using all three vehicles as the donor car, including the vehicle with the well-functioning catalyst. The model results in most cases gave a good prediction of the CO concentration in the cabin. Four case studies of cars used for suicides were described. In each case measurements of CO were made in both the cabin and the exhaust under different starting conditions, and the mathematical model was tested on these cases. In most cases the model predictions were good.

Decomposition and insect succession on cadavers inside a vehicle environment

“…Death by CO poisoning is commonly the result of deliberate exposure to the gas within a confined space, such as a vehicle [16][17][18]. Death occurs as a result of oxygen deprivation at a cellular level whereby the binding of CO to blood haemoglobin in place of oxygen reduces the oxygencarrying capacity of the blood [17,19,20]. Even low concentrations of inhaled CO (1500 ppm) over a prolonged period can result in a lethal concentration of carboxyhaemoglobin in the blood [19,20].…”

“…Death occurs as a result of oxygen deprivation at a cellular level whereby the binding of CO to blood haemoglobin in place of oxygen reduces the oxygencarrying capacity of the blood [17,19,20]. Even low concentrations of inhaled CO (1500 ppm) over a prolonged period can result in a lethal concentration of carboxyhaemoglobin in the blood [19,20]. Death can occur in less than 20 min from initial exposure [17,21,22].…”

Suicide by carbon monoxide from car exhaust-gas in Denmark 1995–1999

“…As catalytic converters reduce the amount of carbon monoxide emitted from the exhaust, the allowed maximum limit for this emission was reduced to 0.5% during idle running for cars newer than 1990. Even this concentration is sufficient to cause death within 5-10 min, but a car with a well functioning catalytic converter emits considerably less carbon monoxide (a few hundred parts per million) [13,14]. Older cars are allowed to emit up to 7% carbon monoxide during idle running (Table 1) [15].…”

Epidemiology of carbon monoxide gas poisoning deaths in Ardabil city, 2008-13

“…[11][12][13][14] For example, in Lutterloh et al study most of patients were in age group 45-64 and in Harduar and Watkins and et al study the most of cases were in age groups 45-54 years. 15,16 But in a study similar to our study in Tehran the most of death were in age groups 20-30 and in another study has been done by Shokrzadeh and et al, the mean age of death cases was 29.8 which were similar to our study.…”