Study on risk of exposure of seafood consumers in Bulgaria to hydrophilic marine toxins

Marine biotoxins can be accumulated in shellfish and in turn can lead to severe illness or chronical consequences in human shellfish consumers. The aim of this study was to assess the levels of hydrophilic marine biotoxins in both farmed and wild mussels from the Bulgarian coast sampled in 2017 and to estimate the exposure (acute and chronic) of detected toxins to Bulgarian consumers if investigated mussels were consumed. The hydrophilic toxin - domoic acid was determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). Mean domoic acid in whole mussel meat was estimated 0.139 mg/kg which is below the regulatory limit of 20 mg/kg. Among all paralytic shellfish (PSP) toxins evaluated only gonyautoxin-2 (GTX2) was detected via high performance liquid chromatography with fluorescence detection (HPLC-FD). Mean GTX2 level in whole mussel meat was calculated to be 0.151 mg STX.2HCl eq/kg which is far beneath the legislative limit of 800 mg STX.2HCl eq/kg. Estimation of acute exposure for both detected toxins - domoic acid and GTX2 and of chronic exposure to domoic acid showed similar results among male and female, as well as among wild and cultivated mussel consumers. This study showed an overall low contamination level of wild and farmed mussels with hydrophilic marine biotoxins compared to the regulatory limits. This is concluding in low acute and chronic exposure via consumption of contaminated mussels.