Identifying pathways of pharmaceutical exposure in a mesoconsumer marine fish

Pharmaceutical uptake involves processes that vary across aquatic systems and biota. However, single studies examining multiple environmental compartments, microhabitats, biota, and exposure pathways in mesoconsumer fish are sparse. We investigated the pharmaceutical burden in bonefish (Albula vulpes), pathways of exposure, and estimated exposure to a human daily dose. To evaluate exposure pathways, the number and composition of pharmaceuticals across compartments and the bioconcentration in prey and bonefish were assessed. To evaluate bioaccumulation, we proposed the use of a field-derived bioaccumulation factor (fBAF), due to variability inherent to natural systems. Exposure to a human daily dose was based on bonefish daily energetic requirements and consumption rates using pharmaceutical concentrations in prey. Pharmaceutical number and concentration were highest in prey, followed by bonefish, water and sediment. Fifteen pharmaceuticals were detected in common among bonefish, prey, and water; all of which bioconcentrated in prey and bonefish, and four bioaccumulated in bonefish. The composition of detected pharmaceuticals was compartment specific, and prey were most similar to bonefish. Bonefish were exposed to a maximum of 1.2 % of a human daily dose via prey consumption. Results highlight the need for multicompartment assessments of exposure and consideration of prey along with water as a pathway of exposure.