Contaminants of emerging concern (CECs) are unregulated chemicals that enter waterways and have the potential to harm aquatic and human health. CECs are commonly introduced into aquatic environments through the use of personal care products, but our understanding of the impact of these chemicals on the development of aquatic organisms remains limited. The zebrafish model system (Danio rerio) has been widely used in environmental toxicology to explore the harmful effects of various environmental pollutants. Here, we explored how three common CECs (acetaminophen, DEET, and triclosan) impacted the development of zebrafish embryos both in isolation and in combination with one another. To determine the effects on zebrafish development, embryos were exposed to increasing concentrations of CECs to quantify the lethal dose. Then, embryos were exposed to sublethal concentrations of CECs for three days and we quantified the effect on development (angle of development and developmental stage), metabolism (yolk sac diameter), and brain growth (eye circumference).
Results/Conclusions
Initial results indicate that typical lethal doses on the CECs explored here were on the order of 1X10^6 times higher than commonly measured environmental concentrations. However, sublethal effects on the growth and development of embryos were observed at concentrations much lower than the lethal dose. For example, acetaminophen showed a 100% mortality rate at a concentration of 2000 mg/L (compared to environmentally relevant concentrations of ~10 µg/ L) but concentrations as low as 100 mg/L resulted in measurable differences in development and metabolism. Here we will further explore the sublethal impact of CECs on organismal development and discuss the impact of simultaneous exposure to multiple CECs.