Facilities & Laboratories
Radiochemistry Laboratory
The radiochemistry laboratory at the Marine Sciences Laboratory (MSL) has the ability to measure natural series, cosmogenic and bomb-produced radionuclides (e.g. 210-Pb, 137-Cs and 7-Be) in environmental samples using alpha and gamma counting techniques (Crecelius, 1975; Brenner et al., 2002, 2004). Measurement of these radionuclides in water, sediments, and air are routinely used as powerful tracers of natural processes or tools in environmental “forensic type” investigations. Examples include: Historical Reconstructions of Contaminant Input Investigation of Particle Transport, Coagulation and Aggregation Processes Determination of Rates of Sediment Mixing by Benthic Invertebrates Investigations of the Behavior and Fate of Particle-Reactive Contaminants Determination of Sedimentation Rates Geochronology Studies
Age Dating of Sediment CoresOne of the most common uses of radionuclide’s in environmental studies (that we routinely employ at MSL) is the determination of the age of various sediment layers (geochronology) in a sediment core. The isotopes typically used for this determination in terrestrial and coastal marine environments are 210-Pb and the bomb-produced isotope 137-Cs. This methodology is based on the pioneering work of Koide, Bruland, Goldberg and co-workers (Koide et al. 1973). The 210-Pb dating method is based on the assumption that there is a constant rate of sediment accumulation with a relatively uniform grain size distribution and that the activity of 210-Pb declines exponentially down the core. 137-Cs serves as an independent geochronology marker in sediments as it originated from above ground weapons testing having peak inputs into the atmosphere in 1963.
Radiochemistry InstrumentationInstruments at MSL for the determination of alpha emitting radionuclides and gamma emitting radionuclides.
ReferencesBrenner RC, VS Magar, JA Ickes, EA Foote, JE Abbott, LS Bingler, and EA Crecelius (2004). Long-Term Recovery of PCB-Contaminated Surface Sediments at the Sangamo-Weston / Twelvemile Creek / Lake Hartwell Superfund Site. Environmental Science & Technology 38(8): 2328-2337.
Brenner, Richard C., Victor S. Magar, Jennifer A. Ickes, James E. Abbott, Scott A. Stout, Eric A. Crecelius, and Linda S. Bingler (2002). Characterization and FATE of PAH-Contaminated Sediments at the Wyckoff/Eagle Harbor Superfund Site. Environmental Science & Technolog, 36: 2605-2613.
Crecelius, E.A., M.H. Bothner, and R. Carpenter (1975). The Geochemistries of Arsenic, Antimony, Mercury and Related Elements in Sediments of Puget Sound, Washington. Environmental Science & Technology, 9:3 25-333.
Koide, M., K. W. Bruland and E. D. Goldberg (1973). Th-228/Th-232 and Pb-210 geochronologies in marine and lake sediments, Geochim. Cosmochim. Acta. 37: 1171-1187.