Trace elements and their potential risk assessment on polar ecosystem of Larsemann Hills, East Antarctica

Abstract

Antarctica is considered pristine despite the gradual emergence of certain pollutants (trace elements and PAHs) from various sources. Environmental matrices viz, soil, lichen, bryophytes, and epilithic mat were collected and analyzed for major and trace elements from Larsemann Hills, East Antarctica. The biotic community-identified up to genera were algae (21), bryophytes (3) and lichens (2). The average lowest and the highest concentration of trace elements recorded were Hg, Cr for soil; Cd, Zn for lichen; Cd, Sr for bryophyte and Hg, Sr for epilithic mat respectively. The ER and Igeo indicate that Se is highly contaminated in all sample types, whereas; Hg is moderately enriched in bryophytes and lichen. However, the source of contamination is natural. Principal component analyses and cluster analysis identified two natural metal contamination sources: ornithogenic and geogenic. The potential ecological risk index indicates a moderate level of contamination for As, Cr, Cu, and Zn. The element Cd and Hg are a matter of concern from their moderate to high ecological risk in some sites of the LH of Antarctica.