Guidance Level for Brevetoxins in French Shellfish

Nathalie Arnich,Zouher Amzil,Marie-Yasmine Dechraoui Bottein,Raphaele Le Garrec,Estelle Chaix,Nicolas Delcourt,Vincent Hort,César Mattei,Eric Abadie,Katia Comte,Jordi Molgó

doi:10.3390/md19090520

Abstract

Brevetoxins (BTXs) are marine biotoxins responsible for neurotoxic shellfish poisoning (NSP) after ingestion of contaminated shellfish. NSP is characterized by neurological, gastrointestinal and/or cardiovascular symptoms. The main known producer of BTXs is the dinoflagellate Karenia brevis, but other microalgae are also suspected to synthesize BTX-like compounds. BTXs are currently not regulated in France and in Europe. In November 2018, they have been detected for the first time in France in mussels from a lagoon in the Corsica Island (Mediterranean Sea), as part of the network for monitoring the emergence of marine biotoxins in shellfish. To prevent health risks associated with the consumption of shellfish contaminated with BTXs in France, a working group was set up by the French Agency for Food, Environmental and Occupational Health & Safety (Anses). One of the aims of this working group was to propose a guidance level for the presence of BTXs in shellfish. Toxicological data were too limited to derive an acute oral reference dose (ARfD). Based on human case reports, we identified two lowest-observed-adverse-effect levels (LOAELs). A guidance level of 180 µg BTX-3 eq./kg shellfish meat is proposed, considering a protective default portion size of 400 g shellfish meat.

Highlights

Brevetoxins (BTXs) are a group of lipophilic marine biotoxins mainly produced by the dinoflagellate Karenia brevis, which forms harmful algal blooms known as red tides
The aims of this work were first, to examine toxicological data in order to identify a lowest observed adverse effect level (LOAEL) possibly appropriate to calculate an acute oral reference dose (ARfD); second, to propose a guidance level in shellfish to protect human consumers; third, to identify investigations required if the guidance level was exceeded; and to provide recommendations for the monitoring of BTXs in the marine environment
There are few cases reported in the literature of human intoxications related to the ingestion of BTX-contaminated shellfish

Summary

Introduction

Brevetoxins (BTXs) are a group of lipophilic marine biotoxins mainly produced by the dinoflagellate Karenia brevis, which forms harmful algal blooms known as red tides. More than 70 analogues and metabolites of BTXs have been reported, most of them are issued from their metabolism in shellfish [1]. BTX-2 is the major analogue produced by K. brevis, while BTX-3 was reported at higher level than BTX-2 in shellfish, i.e., in oysters (Crassostea gigas) and cockles (Austrovenus Stutchburyi) in New Zealand [4,5,6]; in horse conch (Triplofusus giganteus), lightning whelk (Sinistrofulgur sinistrum), banded tulip (Cinctura hunteria), fighting conch (Strombus alatus), pear whelk (Fulguropsis spirata), clam (Mercenaria spp.) and oyster (Crassostrea virginica) in Florida [7,8,9]. According to a recent systematic review of the literature carried out by Young et al 2020 [10], BTXs account for 7.9% of the studies (30/380 publications from 1985 to 2019) on human health effects associated with the efflorescence of marine microalgae and their toxins

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