Human Pharmaceuticals in the Marine Environment: Evidence of occurrence, direct impact and potential ecotoxicological effects on blue mussels, Mytilus edulis

A growing body of literature suggests that pharmaceuticals used in human medicine pose an increasing contamination risk to non-target organisms and indeed to the overall health of marine ecosystems. However, data concerning the level and nature of that risk is lacking. This is particularly true for developing countries such as Indonesia, where the precarious service of wastewater treatment, especially domestic wastewater is threatening the coastal marine environment.

The present research investigates the biological responses and potential
ecotoxicological effects of acetaminophen and metformin, two of the most commonly used human pharmaceuticals, on the marine bivalve Mytilus edulis. This is the first study to record the contamination of Indonesian marine waters (Jakarta Bay) with acetaminophen. Among the studied effects, this research focuses on biological responses recorded both in adults and at the early life stage, in mussels exposed to pharmaceuticals under laboratory conditions. Special emphasis was placed on histological and cytological effects, as well as the impact on molecular pathways, with several reproduction related genes such as vitellogenin and estrogen receptor-2 being strongly modulated by the selected contaminants. The variation in mRNA expression of four other genes involved in apoptosis: heat shock protein-70, caspase-8, B-cell lymphoma-2 and Fas cell surface death receptor was also investigated.

In summary, this study provides the first record to date of acetaminophen presence in Indonesian seawater, with one of the highest contamination levels published so far globally. Furthermore, it provides a comprehensive and integrative assessment of the short- and long-term effects of acetaminophen and metformin in marine mussels Mytilus edulis. Indeed, to date this is the first study recording the effects of acetaminophen in Mytilus edulis, and is also the first study recording the effects of both acetaminophen and metformin specifically on the early life stage of Mytilus edulis. Finally, it discusses the significance of these two most highly consumed pharmaceuticals in the context of marine pollution and the possible consequences for survival of coastal marine species.