After a Kansas City woman died under a kitchen sink in March, authorities suspected sewer gas asphyxiation because of the unmistakable stench that filled the house.
At the time, local plumbers and doctors said they never had heard of such a thing happening in a residence. Even national experts said residential deaths from sewer gas were extremely rare.
But the Jackson County medical examiner’s office recently confirmed that Bernice Weaver, 44, died from inhaling sewer gas. She was homeless but had been staying at the home in the 300 block of North Belmont Avenue with a friend for several months. Her roommate was not home when Weaver collapsed.
The doctor ruled her death an accident from “hydrogen sulfide intoxication,” according to the recently released autopsy results. The results noted methamphetamine abuse and asthma as contributing factors.
Hydrogen sulfide, commonly known as sewer gas, is produced from the decay of organic material, according to the chemist who performs toxicology tests for the county. When inhaled at high levels, the gas starves the victim’s cells of life-sustaining oxygen, similar to the way carbon monoxide kills.
Weaver apparently had poured Liquid Fire, a powerful drain cleaner, into a pipe under the sink after she and her roommate disassembled the plumbing to deal with a clog. But drain cleaner should not produce hydrogen sulfide, said Dan Ferguson, the medical examiner’s office spokesman, although “it may have enhanced the release of hydrogen sulfide from the water.”
The medical examiner’s office said it had one other case of hydrogen sulfide intoxication, in 2010, but details were not available.
Kansas City Health Department officials said they have death records from 2005 to 2009 that show no deaths from hydrogen sulfide intoxication.
“It’s really interesting to see this big list of deaths and that does not appear anywhere on the list,” said Jeff Hershberger, the health department spokesman. “I think that shows how unusual this is.”
Yet deaths from inhaling toxic sewer gas could be more common than people know, said Nick Gromicko, the founder of the International Association of Certified Home Inspectors. He said sewer gas deaths written off to other causes could have been missed if autopsies weren’t performed.
“This could just be the first one we’ve discovered,” he said. “Usually it takes a cluster of people to die before a connection is made.”
Still, Gromicko said, Weaver’s death could have been due to a unique set of circumstances: the missing trap, methamphetamine abuse, asthma and drain cleaner.
“Does it happen a lot and people don’t notice? That’s happened in history before,” he said. “Or is it a bad combination of things?”
Deaths from sewer gas in industrial situations are well documented because a federal agency investigates workplace deaths. No such agency is involved in residential deaths, Gromicko said.
Building codes require plumbing traps for a reason, he said — to prevent sewer gas from leaking into enclosed homes. But he noted there are no codes that require the traps to contain water.
Without water in them, dry traps are useless, he said, “and just a bend in the pipe.”
“My guys find dry traps all the time,” he said.
Gromicko said residents who smell sewer gas should check their traps and fill them with water. If the smell persists, he suggests calling a plumber to find the odor’s source.
“It’s never good to be smelling sewer gas,” he said.