Copper poisoning in wild ruminants in the Kruger National Park: geobotanical and environmental investigation

Abstract

A geobotanical and environmental investigation was undertaken to investigate the potential for copper poisoning in wild ruminants within the Phalaborwa area in the Kruger National Park and to confirm that environmental copper pollution associated with smelting operations at a nearby mine was the source of copper responsible for the poisoning. The study area selected was divided into high, moderate and low-risk zones and a control area based on initial topsoil copper concentrations and impala (Aepyceros melampus) liver copper concentrations in relation to distance from the copper smelter. Samples collected revealed that topsoil copper concentrations were significantly higher than subsoil copper concentrations at the same sites. There was a significant linear decrease in topsoil to subsoil copper concentration relative to distance from the copper smelter and thus from the high-risk zone to the control area. Copper concentrations of unwashed plant material were significantly higher than washed plant material at the same sites, indicating the deposition of copper on the plant surfaces . Copper deposits in dust fall buckets were significantly higher downwind than upwind from the smelter stack and the presence of atmospheric copper was also confirmed with the aid of low-volume air sampling monitors. The investigation confirmed that the emissions from the copper smelter were sufficient in amount and appropriate in direction to have contributed significantly to the topsoil copper concentrations, unwashed plant copper concentrations and dust fall results.