Bioaccumulation of antimony and arsenic in a highly contaminated stream adjacent to the Hillgrove Mine, NSW, Australia

Abstract

Bioaccumulation and uptake of antimony (Sb) were investigated in a highly contaminated stream, Bakers Creek, running adjacent to mining and processing of Sb–As ores at Hillgrove Mine, NSW, Australia. Comparisons with arsenic (As) were included owing to its co-occurrence at high concentrations. Mean metalloid creek rhizome sediment concentrations were 777±115μgg⁻¹ Sb and 60±6μgg⁻¹ As, with water concentrations at 381±23μgL⁻¹ Sb and 46±2μgL⁻¹ As. Antimony and As were significantly elevated in aquatic autotrophs (96–212μgg⁻¹ Sb and 32–245μgg⁻¹ As) but Sb had a lower uptake efficiency. Both metalloids were elevated in all macroinvertebrates sampled (94–316μgg⁻¹ Sb and 1.8–62μgg⁻¹ As) except Sb in gastropods. Metalloids were detected in upper trophic levels although biomagnification was not evident. Metalloid transfer to riparian vegetation leaves from roots and rhizome soil was low but rhizome soil to leaf As concentration ratios were up to 2–3 times greater than Sb concentration ratios. Direct exposure to the rhizosphere sediments and soils, water ingestion and consumption of aquatic autotrophs appear to be the major routes of Sb and As uptake for the fauna of Bakers Creek.