A novel method of suicide – which poses nearly as much danger to rescue personnel as to victims – appears to be gaining popularity in the United States.
Ten chemical suicides in cars occurred in the United States from 2006 to 2011, according to a report by the U.S. Agency for Toxic Substances and Disease Registry (ATSDR). The data were published in the Sept. 9 issue of Morbidity and Mortality Weekly Report (2011;60:1189-90).
The victims mixed various household chemicals and cleaners to produce toxic gases inside a car, and died from inhaling the fumes, the report said.
The paper shows an upward trend in chemical suicides in automobiles: One occurred in 2006, one in 2007, four in 2009, and four in 2010. But there’s no way of knowing the true numbers, said Dr. Eric Lavonas, associate director of the Rocky Mountain Poison and Drug Center, Denver, and an emergency physician at the Denver Health Medical Center.
"There is no question in my mind this is an upward trend, especially in the past year and a half or so," he said in an interview. "This is an emerging phenomenon and we are seeing more and more cases – each one as tragic as the one before."
The ATSDR drew its data from the 2006-2009 Hazardous Substances Emergency Events Surveillance system and from the 2010 data from the National Toxic Substance Incidents Program. A chemical suicide case was defined as suicide or attempted suicide using mixed chemicals in an automobile, noted lead author Ayana Anderson, a public health official with the Centers for Disease Control and Prevention.
The 10 incidents, which occurred in Connecticut, Florida, New York, North Carolina, Utah, and Washington, resulted in 9 deaths. One person began the attempt but then aborted the action. Four rescue personnel were also affected. Two experienced respiratory irritation, but symptom data were not available for the other two, Ms. Anderson and her colleagues noted.
Nine of the incidents occurred in residential areas, where a total of 85 people were evacuated; 32 required decontamination.
In addition to household cleaners, the victims used an assortment of chemicals, including ammonium hydroxide, aluminum oxide, hydrochloric acid, potassium ferrocyanide, sodium hypochlorite, sulfur, sulfuric acid, and trichloroethylene.
The victims for whom an exact age was available ranged from 22 to 69 years. No exact ages were available for four victims, but two were younger than 18 years and two were older than 18, the report said. Most victims (7) were male.
This suicide method kills quickly, said Dr. Lavonas, who has been involved with two cases not noted in the report. "One good, deep lung-full of hydrogen disulfide causes almost immediate loss of consciousness and cessation of heart and brain activity within minutes." However, the fumes will linger in an enclosed space, endangering emergency personnel who move into a scene without following proper hazardous material protocol.
Because of its effectiveness, most victims are dead by the time emergency responders arrive, so the biggest concern is protecting emergency responders. "Toxic gases will make their way through a structure in unpredictable ways. When we hear about these cases, we need to make sure we just have one dead body. We don’t want our rescuers becoming secondary victims in their efforts to help someone."
If a victim is alive at the scene, decontamination is necessary before resuscitation can begin. "This consists of off-gassing the patient by getting them out of their clothing and running a fan over them," he said. While there is no antidote for hydrogen disulfide poisoning, cyanide poisoning can be treated with hydroxocobalamin.
Signs of chemical suicide are a rotten-egg smell around the car or any enclosed space that can contain gas, said Dr. Paul Pepe, chief of emergency medicine at the University of Texas Southwestern Medical Center, Dallas. "Suspicions should be high if the person looks very dead in the car and has locked themselves in, especially if the windows are taped closed," he said in an interview. Other signs are a car that is not running and that is parked in the open – not in the garage – and printed signs taped to the inside of the car windows. These could be biohazard signs or notes warning emergency responders of toxic gases.
Both physicians agreed that the 10 victims noted in the report are certainly an underestimate of the true incidence. But, they said, chemical suicide in cars is likely to remain relatively uncommon for several reasons, including the difficulty of finding the necessary chemicals, Dr. Pepe said.