Exposures to a selective serotonin reuptake inhibitor (SSRI), sertraline hydrochloride, over multiple generations: Changes in life history traits in Ceriodaphnia dubia

• Multigenerational effects of the pharmaceutical sertraline were investigated on an ecologically relevant species, C. dubia.
• Sertraline is one of the most widely prescribed drugs in North America and Europe to treat clinical depression.
• Sertraline has been detected in surface waters, effluents, sediments, and tissues of non-target aquatic organisms throughout North America and Europe.
• Sertraline delays reproduction, inhibits growth, and decreases the number of offspring produced in the third generation at an exposure concentration of 4.8 µg L−1.
• Sertraline exposure in successive generations might be linked to down-regulation of serotonin reuptake.

Selective serotonin reuptake inhibitors (SSRIs) have been reported to range from low parts per trillion to parts per billion levels in surface waters, wastewater effluents, and sediments. These low levels have led to concern for their potential long-term risks to the survival, growth, and reproduction of aquatic organisms. We investigated the acute and chronic effects of sertraline on the life history traits of Ceriodaphnia dubia over the course of three generations under environmentally realistic concentrations. Acute toxicity of sertraline in C. dubia offspring resulted in a 48 h median effective concentration of 126 µg L−1. Under chronic exposure, the lowest concentration to affect fecundity and growth was at 53.4 µg L−1 in the first two generations. These parameters become more sensitive during the third generation where the LOEC was 4.8 µg L−1. The median effective concentrations (EC50) for the number of offspring per female, offspring body size, and dry weight were 17.2, 21.2, and 26.2 µg L−1, respectively. Endpoints measured in this study demonstrate that chronic exposure of C. dubia to sertraline leads to effects that occur at concentrations only an order of magnitude higher than predicted environmental concentrations. However, this study also demonstrates that multigenerational effects should be considered in chronic exposure studies because standard toxicity tests do not account for increases in sensitivity in successive generations to toxicants.