INTRODUCTION: Marine biotoxins can be accumulated in shellfish and in turn can lead to severe illness or chronical consequences in human shellfish consumers.
AIM: 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 Bulgarian consumers to detected toxins if investigated mussels were consumed. To the group of hydrophilic marine toxins belong amnesic toxins (domoic acid, isodomoic acid) and paralytic toxins (neosaxitoxin, gonyautoxins and their decarbamoyl and N-sulfocambamoyl analogs).
MATERIALS AND METHODS: The hydrophilic toxin – domoic acid (DA) was determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). Paralytic toxins (saxitoxin (STX), neosaxitoxin (NEO), gonyautoxin-1 (GTX1), gonyautoxin-2 (GTX2), gonyautoxin-3 (GTX3), gonyautoxin-4 (GTX4), gonyautoxin-5 (B1), decarbamoyl gonyautoxin-2 (dcGTX2), decarbamoyl gonyautoxin-3 (dcGTX3), decarbamoyl saxitoxin (dcSTX), N-sulfocarbamoyl gonyautoxin-1 (C1), N-sulfocarbamoyl gonyautoxin-2 (C2)) were investigated via high performance liquid chromatography with fluorescence detection (HPLC-FD).
RESULTS: Among all hydrophilic toxins investigated DA and GTX2 were detected in the studied samples. Mean domoic acid in whole mussel meat was estimated to be 0.139 mg/kg mm which is below the regulatory limit of 20 mg/kg mm. Mean GTX2 level in whole mussel meat was calculated to be 0.151 μg saxitoxin dihydrochloride equivalent (STX.2HCl eq)/kg which is far beneath the legislative limit of 800 μg STX.2HCl eq/kg mm. Estimation of acute exposure for both detected toxins – DA 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.
CONCLUSION: This study showed an overall low contamination level of wild and farmed mussels with hydrophilic marine biotoxins compared to the regulatory limits. This leads to the conclusion that there is low acute and chronic exposure via consumption of contaminated mussels
