ChemicalMixtures

Marine and freshwater mammalian predators and fish samples, retrieved from environmental specimen banks (ESBs), natural history museum (NHMs) and other scientific collections, were analysed by LIFE APEX partners for a wide range of legacy and emerging contaminants (2,545 in total). The occurrence data were visualized using graph analytics and predator-prey pair analysis was used to derive the predominant chemical mixtures in the freshwater and marine environments. Predominant chemicals are substances that are most prevalent in terms of number of detected counts in prey-predator pairs. The most frequently co-occurring substances in chemical mixtures from AP&P in the marine and freshwater environments were established. Freshwater and marine environments shared 23 chemicals among their top 25 predominant chemicals. Legacy chemical, including perfluorooctanesulfonic acid (PFOS), brominated diphenyl ethers (BDEs), polychlorinated biphenyls (PCBs), hexachlorobenzene and mercury were dominant chemicals in both environments. Globally, these predominant chemicals have been produced and used in high quantities and were regulated in the 1990s and 2000s. Furthermore, N-acetylaminoantipyrine was a predominant pharmaceutical in both environments. The LIFE APEX application (https://norman-data.eu/LIFE_APEX_Mixtures) was proven to be useful to establish most prevalent compounds in terms of number of detected counts in prey-predator pairs. Nonetheless, further research is needed to establish food chain associations of the predominant chemicals.