Investigation of marine biotoxins and human toxicity

Marine biotoxins are correlated with proliferation of harmful algal blooms (HABs) and can accumulate in seafood products, with severe consequences both on fishery industry and consumer health. Recently, an increase of HABs occurred worldwide due to climate change or anthropogenic activities such as discharge of nutrients from domestic and industrial waste, shellfish translocation and global shipping. Different types of food poisoning are described, i.e. Amnesic Shellfish Poisoning (ASP), Diarrhetic Shellfish Poisoning (DSP), Neurologic Shellfish Poisoning (NSP), Paralytic Shellfish Poisoning, (PSP) and Ciguatera Fish Poisoning (CFP). The symptoms are dependent on the specific biotoxin, and maximum levels have been established for some of them in the global legislation. Moreover, acute reference doses are reported for some marine biotoxins, whereas tolerable daily intakes cannot be determined due to absence of appropriate toxicological data. The real incidence of poisoning events is often underestimated because symptoms are similar to viral or bacterial infections as well as allergic reactions. In addition, the lack of knowledge aiming at the diagnosis and treatment of human patients can represent a serious problem for communities and educational programs are considered efficient tools to prevent these events. The majority of human intoxications are related to the consumption of live bivalve molluscs, which are filter feeders and concentrate marine biotoxins produced by toxic phytoplankton species, but these substances may increase at higher trophic levels in the food chain and therefore also other marine organisms can be involved in foodborne outbreaks. Most marine biotoxins are not destroyed by food technologies like freezing or cooking, and their presence cannot be perceived because they give no particular taste, flavor or smell to food. Monitoring plans are generally performed to assess the risk of seafood contamination, and in vivo assays and chemical analysis are the most frequently used tests. In addition, other rapid methods have been developed, such as ELISA test, receptor binding or antibody-based lateral flow assays and in vitro tests. In this chapter, the authors described the main foodborne illnesses linked to marine biotoxins, their toxicity, detection methods and prevention strategies. In particular, they reported the results of monitoring analyses carried out in samples of Mytilus galloprovincialis collected along the Central Adriatic Coast, Italy.