Sources and composition of chemical pollution in Maritime Antarctica (King George Island), part 1: Sediment and water analysis for PAH sources evaluation in the vicinity of Arctowski station

The paper presents a study regarding the identification of polycyclic aromatic hydrocarbons (PAHs) in fresh waters and surface sediments on the western shore of Admiralty Bay over four sampling seasons from 2017 to 2018. The results were compared to literature data from 2016 to provide a more comprehensive image of the environmental fate of PAHs over the years. The highest value of Sigma PAHs was 82.9 ng/L and 445 ng/g dw in water and sediment samples, respectively. The analysis of PAH indicator ratio values showed that pyrogenic or mixed sources contribute to the PAH pollution in Antarctic sediments and water more than does petroleum. The main source is the combustion of biomass (e.g. as a result of fires) and coal, and PAHs are mostly associated with the activity of stations or are transported to a lesser extent by long-range atmospheric transport (LRAT) from South America. The values of the Sigma LMW/Sigma HMW ratio in sediments indicate that petrogenic sources contribute to PAH contamination, but among the six PAH ratios tested, petrogenic sources were identified as dominant in approximately 17-19% of cases. Lack of coherence in the obtained results confirms the mixed origin of PAHs in the studied samples. Although the differentiation of PAHs sources is still ambiguous, caution is recommended in light of the Antarctic system's evident and rapid response to global and local PAH emissions, and the dependency of accumulation and release cycle processes on weather conditions. A reduction in petrol usage in favour of renewable energy sources, and restriction of tourism are strongly recommended for better preservation of the pristine Antarctic environment.

Automated summary

This study investigated the presence of PAHs in fresh waters and surface sediments on the western shore of Admiralty Bay over several sampling seasons. The results showed that biomass combustion and coal were the main sources of PAHs, with a limited contribution from petroleum sources. The study also indicated a minimal role of long-range atmospheric transport from South America in PAH pollution, with local activities being more closely associated with PAH contamination.