Bioaccumulation and trophodynamics of the antidepressants sertraline and fluoxetine in laboratory‐constructed, 3‐level aquatic food chains

Abstract

Although reports of pharmaceutical bioconcentration in aquatic organisms are increasing, less is known about trophic transfer in aquatic food webs. The bioaccumulation and trophodynamics of sertraline and fluoxetine, 2 selective serotonin reuptake inhibitors (SSRIs) frequently detected in aquatic environments, were tested by exposing constructed aquatic food chains to SSRIs under controlled laboratory conditions. Both of these ionizable, weak base pharmaceuticals showed lower bioaccumulation factors (BAFs) with increasing trophic level (i.e., no biomagnifications) in 2 3-level food chains (Acer platanoides, fed to Asellus aquaticus, in turn fed to Notonecta glauca or Pungitius pungitius). Mean sertraline BAFs in A. platanoides, A. aquaticus, N. glauca, and P. pungitus were 2200 L/kg, 360 L/kg, 26 L/kg, and 49 L/kg, respectively, and mean fluoxetine BAFs 1300 L/kg, 110 L/kg, 11 L/kg, and 41 L/kg, respectively. The weak influence of diet was further demonstrated by measured BAFs being equal to or lower than measured bioconcentration factors (BCFs). Organism lipid content was not positively correlated with BAFs, suggesting that other processes are driving interspecific differences in SSRI bioaccumulation. The empirically derived parameter values were introduced into a proposed bioaccumulation model, and a poor correlation was found between modeled and empirical BAFs (predicted r = -0.63). In conclusion, the apparent lack of biomagnification of these ionizable pharmaceuticals suggests that environmental concern should not necessarily focus only on higher trophic levels, but also on species showing high BCFs at any trophic level. Environ Toxicol Chem 2017;36:1029-1037. © 2016 SETAC.

The Psychoactive Drug Escitalopram Affects Foraging Behavior in Zebrafish (Danio rerio)

“…The SSRIs were developed for humans but may equally influence aquatic organisms at different trophic levels and ultimately disturb natural food webs and thus aquatic communities. It has been demonstrated that SSRIs bioconcentrate in different fish tissues, particularly the brain, and in other aquatic organisms in the aquatic food chain (Brooks et al 2005;Nakamura et al 2008;Schultz et al 2010;Grabicova et al, 2014Grabicova et al, , 2015Boström et al 2017). The SERTs are comparable across different vertebrate taxa, and the 5-HT system is remarkably conserved in animal evolution (Wang et al 2006;Lillesaar 2011).…”

Assessing Potential Vulnerability and Response of Fish to Simulated Avian Predation after Exposure to Psychotropic Pharmaceuticals

“…Thus, the nominal concentrations used here would result in fish plasma concentrations in the range of therapeutic mammalian concentrations, and influence on these neurotransmitter systems could be expected. Earlier studies in our laboratory on the uptake of fluoxetine and sertraline in a similar-sized fish, the nine-spined stickleback ( Pungitius pungitius ), indicated that steady-state concentrations were reached within four to seven days and bioaccumulation factors were in the range of 40–50, with experimental half-lives in aquaria containing fish of six and nine days for sertraline and fluoxetine, respectively [ 31 ]. In addition, there was no significant abiotic degradation of either fluoxetine or sertraline in test media (pH 6.5, 7, or 9) exposed to constant light (995 ± 124 lux) over a 35 d period [ 31 ].…”

“…Earlier studies in our laboratory on the uptake of fluoxetine and sertraline in a similar-sized fish, the nine-spined stickleback ( Pungitius pungitius ), indicated that steady-state concentrations were reached within four to seven days and bioaccumulation factors were in the range of 40–50, with experimental half-lives in aquaria containing fish of six and nine days for sertraline and fluoxetine, respectively [ 31 ]. In addition, there was no significant abiotic degradation of either fluoxetine or sertraline in test media (pH 6.5, 7, or 9) exposed to constant light (995 ± 124 lux) over a 35 d period [ 31 ]. Regarding propranolol, literature data indicate that abiotic degradation is low, with an estimated environmental half-life of >1 year [ 33 ], and that two species of fish ( Hemiculter leucisculus , Carassius auratus ) sampled from the field had bioaccumulation factors in the range of 133–4000 [ 55 ].…”

“…Fish were exposed individually in 5 L glass containers for between seven and nine days per trial (further described in Section 2.3 ). This exposure time was chosen for the SSRIs as no abiotic degradation would be expected to occur [ 31 ], it is sufficient to reach steady state between fish and water ( i.e. , within four to seven days [ 31 ]), and behavioral effects have been detected after this exposure time in other studies [ 10 , 32 ].…”

“…This exposure time was chosen for the SSRIs as no abiotic degradation would be expected to occur [ 31 ], it is sufficient to reach steady state between fish and water ( i.e. , within four to seven days [ 31 ]), and behavioral effects have been detected after this exposure time in other studies [ 10 , 32 ]. Regarding propranolol, no abiotic degradation would be expected to occur during this exposure time [ 33 ], though literature data related to steady state and behavioral effects in fish are scarce (but [ 25 ] detected behavioral effects after a two-week exposure period).…”