Occurrence and risk assessment of domoic acid and its analogs in seafood marketed in South Korea

Amnesic shellfish poisoning (ASP) is a seafood-related neurotoxic disorder caused by domoic acid (DA) and its structural analogs, which can lead to symptoms such as short-term memory loss. Despite its increasing regulatory importance in Korea's seafood safety management, comprehensive data on the occurrence of DA and its analogs remain limited. This study investigated the occurrence of five ASP toxins (DA, epi-DA, and iso-DA A, D, and E) in seafood distributed in Korea and assessed the potential health risks associated with their consumption. A total of 347 seafood samples, representing 19 species of bivalves, crustaceans, fish, and gastropods, were analyzed using two validated methods: high-performance liquid chromatography with UV detection and liquid chromatography-tandem mass spectrometry. ASP toxins were detected in one fish and seven bivalve samples, with iso-DA A being the most frequently detected analog. Contamination was observed from February to November, indicating its presence for most of the year. Risk assessment considered three exposure scenarios: (i) summation of DA and epi-DA, (ii) total ASP with equivalent toxicity, and (iii) total ASP with relative toxicity. Although acute reference dose values remained low overall, they increased sequentially across all scenarios. These findings provide critical baseline data for future risk management and regulatory policies on ASP toxins in Korea's seafood industry.