Five Years Monitoring the Emergence of Unregulated Toxins in Shellfish in France (EMERGTOX 2018-2022)

Abstract

Shellfish accumulate microalgal toxins, which can make them unsafe for human consumption. In France, in accordance with EU regulations, three groups of marine toxins are currently under official monitoring: lipophilic toxins, saxitoxins, and domoic acid. Other unregulated toxin groups are also present in European shellfish, including emerging lipophilic and hydrophilic marine toxins (e.g., pinnatoxins, brevetoxins) and the neurotoxin β-N-methylamino-L-alanine (BMAA). To acquire data on emerging toxins in France, the monitoring program EMERGTOX was set up along the French coasts in 2018. Three new broad-spectrum LC-MS/MS methods were developed to quantify regulated and unregulated lipophilic and hydrophilic toxins and the BMAA group in shellfish (bivalve mollusks and gastropods). A single-laboratory validation of each of these methods was performed. Additionally, these specific, reliable, and sensitive operating procedures allowed the detection of groups of EU unregulated toxins in shellfish samples from French coasts: spirolides (SPX-13-DesMeC, SPX-DesMeD), pinnatoxins (PnTX-G, PnTX-A), gymnodimines (GYM-A), brevetoxins (BTX-2, BTX-3), microcystins (dmMC-RR, MC-RR), anatoxin, cylindrospermopsin and BMAA/DAB. Here, we present essentially the results of the unregulated toxins obtained from the French EMERGTOX monitoring plan during the past five years (2018-2022). Based on our findings, we outline future needs for monitoring to protect consumers from emerging unregulated toxins.

Keywords: BMAA; LC-MS/MS; brevetoxins; cyanotoxins; cyclic imines; shellfish.

Figure 1

Examples of chromatograms obtained for each of the three analytical methods after doping of the mussel matrix with (a) DA, MCs, NOD; (b) OA/DTXs, YTXs; (c) GYM-A, SPX-13-desMe-C, PnTXs, PLTX, PTX-2, AZAs, BTXs.

Figure 2

Percentage of shellfish samples from the EMERGTOX network containing different groups of unregulated lipophilic phycotoxins and microcystins quantified during the period 2018–2022.

Figure 3

Maximum concentrations of unregulated toxins found in shellfish at different sites of the EMERGTOX network in 2018.

Figure 4

Chromatograms obtained with (a) HILIC conditions A for a blank mussel matrix spiked with PSPs and TTX; (b) HILIC conditions B for a blank mussel matrix spiked with ATXs and CYNs.

Figure 5

Concentration of CYN in mussels collected at the Ingril site on the Mediterranean coast during the period 2019–2020. * In order to show the presence of toxins at levels between the LOD and LOQ on the graph, the LOQ value of CYN was attributed to these specific cases.

Figure 6

Maximum concentration of the saxitoxin group in oysters collected at the Arguin site (Atlantic coast) during winters in the period 2019–2022. * In order to show the presence of toxins at levels between the LOD and LOQ on the graph, the LOQ value for each toxin detected was attributed to these specific cases.

Figure 7

HILIC-MS/MS analysis of (a) a mixture of BMAA, D3-BMAA, DAB, D5-DAB, and AEG standards; (b) Oyster sample collected at Baie des Veys.

Figure 8

Evolution of the monthly concentration of BMAA and DAB in mussels at the Kervoyal site (Atlantic coast) during the 2019–2022 period.

Figure 9

Maximum concentrations of BMAA and DAB per year and per site during the 2019–2022 period.

Figure 10

Map of the shellfish sampling sites in France used within the EMERGTOX network. Sites are indicated by red triangles; shellfish species studied at these localities are indicated by symbols defined in the legend.