Lead isotope ratios in bone ash of blesbok (Damaliscus pygargus phillipsi): A means of screening for the accumulation of contaminants from uraniferous rocks

Abstract

This study was done to determine whether blesbok (Damaliscus pygargus phillipsi) from the Krugersdorp Game Reserve (KGR) in Gauteng Province, South Africa have higher concentrations of 238U and higher 206Pb/204Pb and 207Pb/204Pb ratios in their bone ash than blesbok from a nearby control reserve that is not exposed to mine water and has no outcrops of uraniferous rocks. Eight blesbok females from the KGR and seven from the control site, all killed with a brain shot, were used. A Thermo X-series 2 quadrupole ICPMS was used to measure the concentrations of 238U and lead and a Nu Instruments NuPlasma HR MC-ICP-MS to measure the lead isotope ratios in the tibial ash from each animal. KGR blesbok had higher mean concentrations of 238U (P = 0.02) and ratios of 206Pb/204Pb and 207Pb/204Pb (P < 0.00001) than the control blesbok. The probability of rejecting the false null hypothesis of no difference in the 206Pb/204Pb or 207Pb/204Pb ratios between KGR and control reserve animals (the power of the test) was 0.999. The blesbok from the KGR accumulated contaminants from an uraniferous environment. The 206Pb/204Pb and 207Pb/204Pb ratios in tibial ash proved effective in confirming accumulation of contaminants from uraniferous rocks.