Chappell, LL; Colman, J; Lorenzana, RM; McGinnis, P; Troast, R; Yeow, A
One of the most significant sources of human exposure to arsenic is food, with the highest arsenic concentrations found in seafood. In most seafood, organic forms of arsenic, mainly arsenobetaine, predominate (80?99%); however, other arsenicals, both inorganic and organic, may also be present. Arsenobetaine is not considered toxic, but inorganic arsenic is toxic and carcinogenic. Consequently, the speciation of arsenic in seafood is a critical consideration for estimating human health risk from seafood consumption. Commonly, only the total arsenic concentrations are available. For estimating human cancer and non-cancer risks, an approximation is needed for the percent of the total arsenic that is inorganic. A survey and evaluation of the data on arsenic speciation in various types of seafood was performed in order to determine published concentrations of total arsenic and inorganic arsenic in finfish, aquatic invertebrates, and seaweed. Sources of data included the published literature and EPA documents, and covered seafood worldwide, as well as seafood from specific US sites. A goal of this survey was to determine if default values could be derived for the percent inorganic arsenic in various types of seafood. While average percent inorganic arsenic values typically are <10% for fish and shellfish, the percent inorganic arsenic values for individual samples of a particular type of fish or shellfish can vary widely from not detected to nearly 30%. Frequently, the quality of the data was not documented and the number of samples limited. In seaweed samples, the percent inorganic arsenic values vary even more widely, from <1% to 60%. Data were not adequate to determine whether the percent inorganic arsenic differs in seafood from contaminated versus uncontaminated areas. This literature review indicates that a nation-wide default that accurately characterizes the percent inorganic arsenic in fish, shellfish, or seaweed is not supported by the available published data.
