A year ago we wrote about a death of a San Jose teenager from poisoning by hydrogen sulfide gas, or H2S. At the time, I had hypothesized that the death might have been from an attempt at synthesizing methamphetamine gone awry.
But while one can mistakenly generate hydrogen sulfide gas from improper meth synthesis, I soon learned that intentional suicides with H2S is an increasing US trend imported from Japan. One can easily mix commonly-available consumer products to generate the gas and high enough concentrations can cause death. The gas acts in a manner similar to cyanide by binding to the heme in cytochrome c oxidase and inhibiting electron transport and ATP production by oxidative phosphorylation in the mitochondria. (Interestingly, small amounts of H2S are made in the body and is being investigated as a neurotransmitter and biological modulator.)
So deadly is hydrogen sulfide that it is considered a major occupational safety hazard for workers in municipal sewage services, industrial manure management on factory farms, and the growing aquaculture industry – the US National Oceanographic and Atmospheric administration provides detailed background and training videos here.
Now we can add first-responders like EMTs to that list. Pulitzer Prize-winning author Deborah Blum alerted me to an article in The Tampa Tribune about hazards to emergency personnel responding to “detergent suicide” attempts. (By the way, Blum just released her new book, “The Poisoner’s Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York,” and writes the beautifully-designed Speakeasy Science blog about culture and chemistry.)
This past Monday a 30-year-old Cary, NC, man committed suicide with hydrogen sulfide by mixing chemicals in a 5-gallon bucket inside his Toyota Camry. The gentleman was well-aware of the risk he posed to those who would find him there. As detailed in the WTVD-TV report embedded below, the man was found slumped over the wheel of his car in his apartment complex parking lot but had left warning signs on the dashboard and seats that read, “HAZMAT TEAM NEEDED” and “DO NOT OPEN!!! POISON GAS!!! Hydrogen sulfide.”
I went back and re-read The Tampa Tribune article and learned that the 23-year-old man who committed suicide similarly in St. Petersburg, FL, over Valentine’s Day weekend had also left similar warning notes in his car.
But in the event readers and emergency personnel see unconscious people inside parked vehicles without warning notes, be aware of the telltale smell of hydrogen sulfide: intense, rotten eggs. In the Cary case, authorities measure hydrogen sulfide gas in the car at three times the lethal concentration and a police officer responding in the St. Petersburg case had to be treated at the hospital after inhaling some of the gas.
I am deeply saddened by these stories because these people felt so badly about themselves so as to end their lives, yet they were compassionate enough to think about the welfare of those who would face risks finding them there.