Species- and tissue-specific bioaccumulation of arsenicals in various aquatic organisms from a highly industrialized area in the Pohang City, Korea

• Species- and tissue-specific bioaccumulation of arsenicals in biota was characterized.
• Arsenic in biota was generally shown to depend on waterborne As contamination.
• Arsenobetaine was found to be a predominant As in biota except for freshwater snail.
• Arsenicals were mainly localized in intestine of fish and bivalve.
• Salinity is the primary factor controlling the biogeochemistry of As in estuary.

Contamination of water and sediment with arsenic (As) in a highly industrialized area of Pohang City, Korea was investigated, with emphasis on in situ bioaccumulation of arsenicals by various aquatic organisms. Species- and tissue-specific concentrations of arsenicals were determined by use of HPLC-ICP/MS and μ-X-ray absorption near-edge structure (μ-XANES). Concentrations of arsenic in aquatic organisms were strongly associated with corresponding water concentrations, which indicates point sources associated with land use and activities. Arsenobetaine was the most dominant form of arsenic found in fishes, bivalves, crabs, and shrimps, while AsIII was predominant in freshwater snails. The μ-XANES analysis provided additional information about the unidentified arsenicals such as As-thiol. Arsenicals were mainly localized in intestine of mullet and marsh clam. Distribution and bioaccumulation of arsenic were strongly correlated with salinity, which indicates that natural processes controlling biogeochemistry of arsenic would be important in estuarine lotic system.