Deposition history of trace metals and fallout radionuclides in wetland ecosystems using 210Pb chronology.
A comparative study has been made of the history of lead and other trace metals that have been deposited on wetlands. A series of sediment cores from the USA, Ireland and the Czech Republic were measured for 210Pb, Pb, other trace metals and the radionuclides 137Cs, 90Sr and 239,240Pu. The 210Pb chronology of the core profiles was established using the CRS method of Appleby and Oldfield and the minimum variance method of Tobin and Schell, i.e., the CRS-MV method. Using the minimum variance of the least-squares fit of the line representing the total core data and propagating the errors, the apparent time error ranges from 2 to 10 years. Cores were taken from Hudson River wetlands, a mountain top bog in the USA, blanket bogs in western and eastern Ireland, and bogs in a highly polluted and a "pristine" zone in the Czech Republic and provided profiles. At the most westward European station in Ireland, the Pb deposition history appears to exceed background levels at dates similar to those in eastern USA, whereas the profiles near Dublin exceed background values at approximately the same date but have maximum deposition values significantly later. Such initiation of the Pb deposition in Ireland could be due to long-range transport across the Atlantic Ocean. In the Czech Republic, the initiation of metal deposition occurs before that in Ireland and the USA, reflecting the earlier development of industrialization and release of metals.
|Main Author:||Schell, W.|
|Other Authors:||Tobin, M., Novak, M., Wieder, R., Mitchell, P.|