ShellfishScientists have warned that harvested shellfish should be screened for toxins to avoid long-term health risks, according to a report published in the Society for Applied Microbiology (SfAM) journal.

In an area with contamination by strains of Penicillium fungus, bivalve molluscs (clams, oysters, mussels, scallops, etc) will contain toxins at much higher levels than those found in the surrounding environment.

Professor Yves François Pouchus, from the University of Nantes, France, led the research: "A high level of toxins in the shellfish tells us that we have to be careful not to underestimate the impact of certain Penicillium strains in the water where shellfish are harvested for human consumption." Professor Pouchus' team found that the fungi produce more toxin when growing inside mussels or in a medium containing mussel extract.

Although toxins from Penicillium don't cause acute food poisoning, they can have a negative impact on cells and DNA. In theory, these mycotoxins could cause health issues in the long term, such as cancer. Pouchus concluded: "At this point, we think it would be pertinent to begin screening edible shellfish for mycotoxins in order to protect consumers."