The presence of "methyl mercury" in fish is well-known, but until now the detailed chemical identity of the mercury has remained a mystery. In an x-ray absorption spectroscopy study published in the August 29 issue of Science (Science 301, 2003: 1203;Science now: Murky Picture on Fish Mercury), SSRL scientists report that the chemical form of mercury involves a sulfur atom (most likely in a so-called aliphatic form). The study presents significant new knowledge - because the toxic properties of mercury (or any element) are critically dependent upon its chemical form - and represents an important milestone in developing an understanding of how harmful mercury in fish might actually be. The study was carried out by SSRL staff scientists Ingrid Pickering and Graham George and postdoctoral fellow Hugh Harris using SSRL's structural molecular biology beam line 9-3. The very high flux, excellent beam stability and state-of-the-art detector technology allowed the team to measure samples of fish containing micromolar levels of mercury, much lower than had previously been possible.
Funding for this research was provided by the U.S. Department of Energy, Office of Biological and Environmental Research and by the NIH National Center for Research Resources, Biomedical Technology Program.
(Note: Ingrid Pickering and Graham George ( ) have recently relocated to the University of Saskatchewan and Hugh Harris to the University of Sydney).
H. H Harris, I. J Pickering and G. N George, "The Chemical Form of Mercury in Fish", Science 301, 1203 (2003)
