Emerging contaminants and legacy pollutants exhibit contrasting exposure and hazard patterns in sediments and suspended particulate matter from an Antarctic coastal ecosystem.

Abstract

Antarctic coastal systems are changing under the combined influence of climate warming and increasing human activity, but the interaction between contaminants of emerging concern (CECs) and legacy contaminants (LCs) remains poorly resolved. Here, we investigated their occurrence, sources, partitioning, and ecological risks in suspended particulate matter (SPM) (n = 15) and sediments (n = 15) from Admiralty Bay, Northern Antarctic Peninsula, using gas chromatography coupled to a quadrupole time-of-flight high-resolution mass spectrometer for CECs, and to a triple-quadrupole mass spectrometer for LCs. In SPM, contaminants showed a heterogeneous distribution across Admiralty Bay and generally higher concentrations. In contrast, sediment contamination was more associated with preferential deposition areas and showed a greater diversity of detected compounds. Source apportionment suggested a combination of local sources, including wastewater discharge, fuel use, and station activities, together with long-range atmospheric transport and secondary remobilization. Risk assessment highlighted a functional difference between contaminant groups. CECs, such as octocrylene and triclosan, drove immediate ecological risk (RQ > 1) due to high exposure in SPM, while LCs, including PCBs and alkylated PAHs, remained dominant in toxicological priority. These findings show that Antarctica is no longer only a passive sink, but an active system where recent inputs and historical reservoirs interact, emphasizing the need for integrated monitoring and management strategies based on exposure and hazard.