Arsenic Speciation in Blue Mussels (Mytilus edulis) Along a Highly Contaminated Arsenic Gradient

• Published in: Environmental science & technology Vol. 46; no. 6; pp. 3110 - 3118
• Main Authors: Whaley-Martin, K. J, Koch, I, Moriarty, M, Reimer, K. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20-03-2012
• Subjects: ABSORPTION SPECTROSCOPY; Animal, plant and microbial ecology; Animals; Applied ecology; AQUATIC ECOSYSTEMS; ARSENIC; Arsenic - analysis; Arsenic - chemistry; Biological and medical sciences; Chromatography, High Pressure Liquid; DISTRIBUTION; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Environmental Monitoring; ENVIRONMENTAL SCIENCES; Fundamental and applied biological sciences. Psychology; Gastrointestinal Tract - chemistry; GLANDS; HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY; Marine and brackish environment; Mass Spectrometry - methods; MASS SPECTROSCOPY; MINING; Mollusks; MUSSELS; Mytilus edulis; PLASMA; SEDIMENTS; SEMIMETALS; Spectrum analysis; Toxicology; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; X-Ray Absorption Spectroscopy; Canada; Nova Scotia; North America; America; Marine environment; Pollutant; Benthic organism; Arsenic; Bivalvia; Mytilus edulis; Harbor; Biological indicator; Invertebrata; Mollusca; Speciation
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es203812u

Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strong arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As–C bonds) and total arsenic concentrations present in M. edulis tissues (R2 = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R2 = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic–sulfur compounds. The XAS mapping revealed that the As­(III)-S and/or As­(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel’s cells in a physiological function such as an intracellular osmolyte.