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High levels of paralytic toxin found in California shellfish

Cheryl Santa Maria
Digital Reporter

Friday, March 9, 2018, 5:58 PM - The California Department of Public Health is advising consumers not to eat recreationally harvested mussels, clams or whole scallops from San Francisco and San Mateo counties, after finding "dangerous levels" of paralytic shellfish poisoning -- or PSP -- in them.

While the toxins are naturally occurring, officials say they're seeing some of the highest levels in twenty years.

Weather a contributing factor

Experts believe an unseasonably warm winter has contributed to the elevation in toxin levels.

PSP is a biotoxin produced by algae, which flourishes under warmer conditions. When shellfish eat the affected algae, they retain the poison and can pass it on to humans.

PSP toxins are not destroyed by cooking and can cause illness or death in humans.

According to SF Gate, Marin County in northern California produced mussels with 37 times the level of PSP that would be considered harmful for human consumption.

The findings have prompted California Public Health to issue a public advisory.

Commercially-sold clams, mussels, scallops or oysters from approved sources are still safe to eat.

PSP toxins affect the central nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating affected shellfish.

A loss of balance, lack of muscular coordination, slurred speech and difficulty swallowing usually follows.

According to state statistics, there have been 542 PSP-related illnesses and 39 deaths in California over the past 90 years.

Sources: California Department of Public Health | SF Gate

Video: Shellfish vs. climate change:

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