Health assessment of marine biotoxins in food

There are around 5,000 different species of algae in the world's oceans. About 300 of these species can occur in such high concentrations that they even discolour the water (red tide). A small percentage of algae species are capable of producing toxic substances known as marine biotoxins (also called algal toxins). The toxins can be stored in the tissue of mussels that feed on such algae. The marine biotoxins do not affect the mussels, but they can cause various illnesses in humans if contaminated mussels are consumed.

Marine biotoxins can accumulate in mussel tissue and, when consumed, can cause diarrhoea or paralysis in humans, among other things, and even lead to death in severe cases. For this reason, mussel harvesting waters and mussels are tested for their health safety before they are released for distribution and consumption.

Algal toxins are categorised into groups depending on the structure or the symptoms caused by the consumption of contaminated mussels. Three groups are relevant for Europe:

• the PSP group (paralytic algae toxins)
• the ASP group (amnesic algae toxins)
• the group of lipophilic toxins (including the DSP group: diarrhoea-causing toxins)

The European Food Safety Authority (External Link:EFSA) has published extensive scientific opinions on marine biotoxins. These address topics such as the occurrence, toxicological effect, detection methods and contamination of mussels, as well as the assessment of limit values.

Until the entry into force of Regulation EU No. 15/2011 on 1 July 2011, the EU reference method for detecting lipophilic marine biotoxins was the mouse bioassay. This animal experiment was not used in Germany for animal welfare reasons. According to Regulation EU No. 15/2011, a transitional regulation is in force in the EU until the end of 2014, during which both the mouse bioassay and alternative methods are permitted. After successful method validation, a chemical-analytical method (LC-MS/MS) replaced the animal experiment as the EU reference method for the determination of lipophilic marine biotoxins.

According to Regulation EC No. 1664/2006, PSP toxins can be determined by chemical-analytical methods such as HPLC. However, the reference method for dubious results is still the mouse bioassay. In Germany, this animal experiment is only used if non-animal testing methods do not provide a meaningful result.

According to Regulation EC No. 1244/2007, ASF toxins are to be determined using HPLC methods or an ELISA.