Assessing the potential for chronic exposure to low levels of domoic acid through the use of Solid Phase Adsorption Toxin Tracking

Domoic acid (DA), (C15H22NO6) is a biologically produced neurotoxin that causes amnesic shellfish poisoning (ASP) in humans (Hallegraeff 2003) and can lead to direct poisoning of marine life or Domoic Acid Poisoning (DAP) (Lansberg 2005). The toxin is produced by marine diatoms of the genus Pseudo-nitzschia. Domoic acid (DA) is an excitatory glutamate analog that can cause neuronal cell death from sustained depolarization and intracellular Ca2+ increases once bound to the glutamate receptor (Fuquay 2012). The subsequent glutamate release can then activate NMDA ionotropic receptors to excite seizure-prone circuitry in the limbic region of the brain; excitation that has been shown to lead to structural damage, particularly in the hippocampus, septum and olfactory bulb (Fuquay 2012). In 1987 DA was found to be toxic to humans. In the first reported outbreak of DA poisoning, toxic shellfish were consumed on Prince Edward Island, Canada, causing three deaths and over 100 people developed various toxic symptoms (Bates 1989). While widely distributed, Pseudo-nitzschia is most prolific on the west coast and northeast United States and not thought to be problematic in the southeast (Hasle 2002).