Superfund Research Program
Mechanisms and Consequences of Evolved Adaptation to Environmental Pollution
Studies in the past year have continued to build upon and expand the project team's understanding of pollution as a driver of evolution, the “cost” of genetic adaptations that allow animal populations to thrive in polluted environments, and mechanisms underlying these adaptations. This research has primarily revolved around a real world “case study” in the Elizabeth River, VA, where specific sites were highly contaminated by polycyclic aromatic hydrocarbons (PAHs). One of these sites, Atlantic Wood Industries, is a designated Superfund site that has undergone extensive remediation in the last several years. Another former wood treatment site (“Republic”) now serves as the team's major high PAH site while King’s Creek (KC) continues to serve as the project's primary reference site. In total, the team is investigating eight sites that cover a broad range of contamination. Recent results demonstrate that the developmental toxicity of sediment extracts for these sites tracks the concentrations of PAHs in the extracts (Volkoff 2019). A related field study demonstrated profound differences in the expression of genes associated with heart development and function between killifish from the Atlantic Wood Industries site and the King’s Creek reference site (Osterberg 2018). These impacts appear to be in part associated with the detrimental effects of PAHs on mitochondria, the energy producing organelle of cells also impacted by hypoxia (Lindberg and Di Giulio, 2019). These results have important ramifications for risk assessment: the ability of animals to adapt to pollution may result in the underestimation of site-specific risk assessments if fitness costs are not addressed.