PROGRAMME

The contamination of the aquatic ecosystem with organic micropollutants due to anthropogenic activities, over the last decades, is a well-known issue. Due to the frequent detection of these chemicals in various environmental compartments, they are considered as potential threats to the aquatic ecosystem. Although a percentage of them has been studied in detail since 1980s and are already included in existing legislation or monitoring programmes, thousands of organic micropollutants, characterized as chemicals of emerging concern, are not subjected to marketing restrictions and regulatory monitoring programmes but are candidates for future regulation, due to their frequent detection in environmental samples and their potential hazardous properties (Thomaidis et al, 2012; Gavrilescu et al, 2015; Dulio et al, 2018). The distribution of organic micropollutants in the living organisms and, subsequently, their bioaccumulation in the upper trophic levels of the food webs, along with their potential toxic properties, underline the necessity for regular environmental monitoring studies (Badea et al., 2020; Montesdeoca-Esponda et al., 2018). Furthermore, chemicals detected in organisms are highly possibly bio-accumulative (B) and persistent (P), thus fulfilling two out of three PBT criteria considered under REACH legislation. Consequently, the systematic monitoring of organic micropollutants in biota specimens is of high importance, in order to identify the emergence of chemicals including substitutes of regulated compounds, which may present similar levels of hazard. Apex predators play a key role in the monitoring of environmental contaminants and in risk assessment studies for a number of reasons including: their position at the top of food webs, a relatively long lifespan over which they accumulate contaminants, integration of exposure both over time and relatively large spatial areas, relative ease with which samples can be obtained, and relative ease with which populations can be quantified and monitored (Movalli et al, 2017). The occurrence of persistent organic micropollutants in remote areas, including Arctic and Antarctica regions, will contribute in the prioritization of these substances. It is expected that, due to the global warming, the polar areas will become more accessible and, consequently, more polluted from anthropogenic activities. Although the occurrence of many organic micropollutants has been investigated in Arctic region through targeted analytical methodologies, in the context of Arctic Monitoring and Assessment Programme (AMAP, 2017), the contamination and sources of persistent chemicals in the Antarctic continent have not been systematically investigated yet. In order to assess the presence of ubiquitous organic micropollutants in biota specimens from remote areas, 4 samples of organisms from the lower trophic levels (macrophyte, sea star, sea urchin, fish) and 10 apex predator samples (3 different matrices; placenta from Weddell Seal, muscle from Gentoo Penguin and Crabeater Seal, egg from Adelie Penguin and Gentoo Penguin) were gathered from 2018 to 2020 in Antarctica and were analyzed following state-of-the-art wide-scope target screening methodologies. The samples were lyophilized before analysis, in order to enhance extraction efficiency, improve the precision and achieve lower detection limits. The analytes were extracted from the dry matrices through generic methods of extraction, using Accelerated Solvent Extraction (ASE), followed by a clean-up step using Solid Phase Extraction. The final extracts were analyzed by different complementary chromatographic techniques (both liquid and gas chromatography) and ionization modes (using electrospray and atmospheric pressure ionization) coupled to High Resolution Mass Spectrometry, in order to broaden the chemical domain accessible to wide-scope target analysis and suspect screening. The samples were screened for the presence of more than 2,400 organic pollutants, included in the target list of the National and Kapodistrian University of Athens (NKUA). NKUA database includes compounds of different classes (such as pharmaceuticals, personal care products, biocides, plant protection products, illicit drugs, stimulants, sweeteners, and industrial chemicals, e.g. per- and polyfluorinated compounds (PFASs), flame retardants, corrosion inhibitors, plasticizers, surfactants), as well as their transformation products and metabolites [The LC target list is available as S21 UATHTARGETS in the NORMAN Suspect List Exchange https://www.norman-network.com/ nds/SLE/ (DOI: 10.5281/zenodo.3723478) and the GC target is available as S65 UATHTARGETSGC (DOI: 10.5281/ zenodo.3753372)]. The target list is being updated on a regular basis, since new compounds of concern are continuously being identified. Moreover, the archived HRMS chromatograms were uploaded into NORMAN Digital Sample Freezing Platform (DSFP) for the suspect screening of more than 65,000 chemicals, included in the NORMAN SusDat (Alygizakis et al, 2019). These data are also available for future retrospective screening of organic micropollutants. Strict criteria of mass accuracy (<2mDa), isotopic fitting (mSigma<50), retention time (<0.20 min) and fragmentation pattern match were applied during the screening process, while the standard addition method was used for quantification purposes of the detected analytes (Gago-Ferrero et al, 2020). Preliminary results indicate the presence of dozens of organic micropollutants in low concentration levels (μg/L). Specifically, chemicals classified in different categories, such as personal care products ( galaxolide, benzophenone-3 and methylparaben), plant protection products (including fenuron and endothall) and pharmaceuticals (for example hydrocortisone). Moreover, parent and transformation products were detected in the Antarctica organisms (such as nicotine and nor-nicotine), underlying the added value of wide-scope target screening.