title: Ecological half-life of 137Cs in plants associated with a contaminated stream.
abstract: Ecological half-life (Te) is a useful measure for studying the long-term decline of contaminants, such as radionuclides, in natural systems. The current investigation determined levels of radiocesium (137Cs) in two aquatic (Polygonum punctatum, Sagittaria latifolia) and three terrestrial (Alnus serrulata, Myrica cerifera, Salix nigra) plant species from a contaminated stream and floodplain on the U.S. Department of Energy's Savannah River Site. Current 137Cs levels in plants were used in conjunction with historical data to determine Te of 137Cs in each species. Median concentrations of 137Cs were highest in S. latifolia (0.84 Bq g(-1)) and lowest in M. cerifera (0.10 Bq g(-1)). Te's ranged from 4.85 yr in M. cerifera to 8.35 yr in S. nigra, both terrestrial species. Te's for all aquatic (6.30 yr) and all terrestrial (5.87) species combined were very similar. The Te's of the two aquatic primary producers (P. punctatum and S. latifolia) in the Steel Creek ecosystem were somewhat longer than Te values previously reported for some consumers from this ecosystem.
authors.affiliation: 207 Ostermayer Laboratory, Pennsylvania State University-McKeesport, 15132, USA. jdp12@psu.edu
authors.forename: John D
authors.initials: JD
authors.lastname: Peles
authors.forename: Michael H
authors.initials: MH
authors.lastname: Smith
authors.forename: I Lehr
authors.initials: IL
authors.lastname: Brisbin
mesh_terms: D002588:Cesium Radioisotopes / Q000493:pharmacokinetics; D017753:Ecosystem; D004784:Environmental Monitoring; D006207:Half-Life; D010944:Plants; D014018:Tissue Distribution; D014875:Water Pollutants, Radioactive / Q000493:pharmacokinetics*
chemical_list: D002588:Cesium Radioisotopes; D014875:Water Pollutants, Radioactive