SSRIs antidepressants in marine mussels from Atlantic coastal areas and human risk assessment

Selective serotonin reuptake inhibitors (SSRIs) are among the most prescribed antidepressants nation and worldwide. Their presence in the aquatic environment is known, causing growing pressures in heavily populated coastal areas. For instance, disruption of invertebrate endocrine systems has been described. Since discrete seawater sampling may not be suitable to evaluate such environmental risk, we aimed to assess SSRIs and metabolites in wild Mytilus galloprovincialis, and assess risk to human health. A total of 1225 mussels were sampled during one year along the Portuguese Atlantic coast. Each freeze-dried pool of 25 specimens was analyzed, in duplicate, by solid phase extraction (SPE) and liquid chromatography with tandem mass spectrometry (LC-MSn). Approximately 70% of the samples were contaminated with at least one, and up to 4 from the 7 targeted compounds. The cumulative SSRIs and metabolites content in mussels ranged between 3.17 and 33.93ngg^-1 dry weight, in a mean level of 14.68±9.69ngg^-1. Norfluoxetine was the most recurring SSRI and the one with the highest mean concentration, 13.52ngg^-1. Although some differences were found between different sampling periods and locations, those were not statistically significant (p>0.05) and no correlation was found between wet weight and mean contamination levels. Regarding risk to human health following consumption of these filter-feeders, when considering the average sample contamination of positive samples and the average Portuguese and European consumption, the ratio between the estimated daily intake (EDI) and the acceptable daily intake (ADI) ranged from 0.45 to 5.50%, and from 1.60 to 19.41%, respectively. Therefore, although the resultant risk is lower for the Portuguese consumer than for the average EU consumer, apparently, no appreciable risk to human health is expected.