Emerging contaminants and priority substances in marine sediments from Cartagena Bay and the Grand Marsh of Santa Marta (Ramsar site), Colombia

Emerging pollutants and priority substances are of growing concern due to their toxicity potential to aquatic organisms and human health. However, few reports on this issue in marine ecosystems in general and, more specifically, on the Colombian Caribbean coast are available. The aim of this study was to detect these compounds in sediments from Cartagena Bay (CB) and in the Grand Marsh of Santa Marta, GMSM (Ramsar site), in order to determine how they related to in vitro cytotoxicity assays on HepG2 cells of sediment extracts. A total of thirty compounds were detected using GC-MS/MS in fifteen stations during both the rainy and the dry seasons. Sediments from CB had a wide range of different toxicants, with polycyclic aromatic hydrocarbons (PAHs) being the most prevalent (12 PAHs, 5.5-881.6 ng/g). Total PCBs ranged from < LOD to 18.6 ng/g, with PCB 138 being the most common detected congener. Residues of p,p '-DDE, Chlorpyrifos and two organophosphate flame retardants, TEHP and ToTP, were found in most sampling locations. The UV filters 4MBC and homosalate were recurrently found in sediments, and the fragrance galaxolide appeared in all cases, with the greatest concentrations found on a touristic beach. In GMSM, with the exception of deltamethrin, all chemicals evaluated had lower average values than in CB. According to sediment quality guidelines, some sites in CB presented values of PAHs higher than the threshold effects level, while in the marsh, none of the stations exceeded it. HepG2 cells exposed to 1% sediment extracts presented reduced cell viability up to 26%. Cytotoxicity displayed a negative correlation with chlorpyrifos concentration. In short, these data suggest the bay and the marsh have specific contamination fingerprints related to anthropogenic interventions. This research highlights the need to further investigate the ecotoxicological implications of detected chemical stressors in these ecosystems.