Assessing ecotoxicity of surface water and sediment in the Little Scioto River

Environmental health and safety (EHS) is a globally interconnected discipline.  The health of benthic species, for example, can ultimately affect human health through bioaccumulation and biomagnification of contaminants up the food chain.  Characterizing the toxicological effects of anthropogenic pollution on ecological receptors helps EHS specialists develop plans for remediating contaminated sites and helps inform industrial policy regulation, providing a cleaner and safer environment for future generations.

Key Insights:

  • Healthy, lab-reared organisms were exposed to contaminated water and sediment samples from a former wood treatment facility in Ohio.
  • Tests were performed to evaluate the short-term (acute) and long-term (chronic) effects to four different aquatic species.  The tests measured several parameters including survival, growth, and reproduction.
  • Surface water samples showed acute toxicity to water fleas, but only at the highest concentration (undiluted sample).  Without a dose-response relationship in lower concentrations, causation cannot be established.  Surface water samples also showed chronic toxicity to fish larvae, but only at the highest concentration and only in the upstream sample.  This toxicity is attributed to sources other than the target site.
  • No sediment toxicity was observed as hypothesized; rather, midge growth was enhanced in the most contaminated samples and was lowest in the sample furthest from the source.  This may indicate this benthic species uses the contaminants as a food source.  Water flea survival was not impacted, and reproduction was observed in all samples.