Overview:
A Contra Costa County resident died recently after mistakenly eating poison mushrooms.
Toxic mushrooms grow abundantly in East Bay parks, where foraging is prohibited.
There have been nearly three dozen poisoning cases statewide this season.
Contra Costa Health has confirmed that a county resident recently died after eating wild mushrooms and is reminding foragers that some toxic varieties closely resemble edible ones.
The county health department is warning residents to “not eat wild mushrooms unless you are absolutely certain of their identification and have expert experience.”
The California Department of Public Health issued an alert saying California is experiencing an “unprecedented outbreak of severe illness and deaths associated with people accidentally picking and eating Death Cap mushrooms.”
As of Jan. 6, 35 cases, including three adult fatalities and three liver transplants, have been linked to the ongoing outbreak.
The cases were reported across Northern California and the Central Coast, spanning regions from Sonoma to San Luis Obispo. Affected individuals range in age from 19 months to 67 years and include family groups and individuals. According to news reports, the Contra Costa County person was a man in his 60s.
Think you ate a poison mushroom?
Symptoms of mushroom poisoning, which include abdominal pain, vomiting, cramping, diarrhea and nausea, typically appear about 12 hours after consumption.
If you think you may have eaten a poisonous mushroom, seek medical care immediately or call Poison Control at 1-800-222-1222.
Death cap mushrooms can be found statewide but are particularly adjacent to oaks, other hardwoods and some pines.
Poisonous shrooms thrive in East Bay parks
It’s unknown where the Contra Costa person found the mushrooms, which are abundant in the East Bay Regional Park District (EBRPD), which issues standing warnings every rainy season of the dangers posed by toxic mushrooms. A spokesperson told Richmondside via email that park police have “no information related to a mushroom-related death on District property in Contra Costa County.”
Two of the world’s deadliest types thrive in the East Bay: the Amanita phalloides (death cap) and the Amanita ocreata (Western destroying angel).
Both are associated with oak trees, and can be found growing anywhere oak roots are present, according to the park district, which prohibits foraging. Richmondside reached out to parks officials about the recent death but did not hear back as of publication time.
Courtesy of the state health department
Both the death cap and the destroying angel contain amatoxin, a lethal chemical compound that causes liver failure. Symptoms of mushroom poisoning, which include abdominal pain, vomiting, cramping, diarrhea and nausea, typically appear around 12 hours after consumption.
Mushrooms tend to thrive after heavy rains, but when it comes to deadly amanitas, it’s not a hard and fast rule, Debbie Viess, a retired zoologist who founded the Bay Area Mycological Society, said in 2023.
“Mushrooms don’t behave the same all the time. They have windows of fruiting and they have times that they like to fruit,” Viess said. “Amanitas share resources with many other mushroom species on the same tree. Sometimes they take turns, and sometimes they compete, so there’s really no predicting what’s going to come.”
Other species of mushrooms, including the Lactarius rubidus (candy cap) — great in ice cream — and the plump, orblike Calvatia gigantea (giant puffball) — which can be sliced into discs and turned into a “pizza” — also thrive in East Bay parks.
Experts generally advise against eating foraged mushrooms — especially when it’s one you can’t identify with utter certainty.
In 1996, an Orinda mother and her three children were hospitalized with liver failure after eating mushrooms they picked at Lafayette Reservoir, according to an SFGate report.
According to the National Institutes for Health, over the last 18 years there have been an average of 7,428 reported mushroom poisonings a year.
Pets are also at risk. In early 2023, a Berkeley resident spoke out to warn others after her puppy died from eating a death cap in Codornices Park. A Berkeley animal hospital said it sees about 20 suspected pet poisonings annually.
To safely learn more about fungi, explore the East Bay Regional Park District’s toxic mushroom page which contains handy photos of mushrooms to avoid.
And if you’re determined to go foraging, you might consider visiting Salt Point State Park, which is about two hours north of Richmond in Sonoma County. It’s the only state park that allows mushroom picking, and there you can find expert guides who will help ensure that what you’re harvesting is safe to ingest.
This story includes information from a story by Iris Kwok originally published in January 2024.
You write: “Experts generally advise against eating foraged mushrooms”. This is nonsense. This is the sort of know-nothingism sometimes issued by agencies with little knowledge of mushrooms, but I challenge you to cite even one relevant expert giving such a point of view. Experts do regularly warn people to eat only well-identified edibles.