A comparison of particulate hexavalent chromium cytotoxicity and genotoxicity in human and leatherback sea turtle lung cells from a one environmental health perspective

Evaluating health risks of environmental contaminants can be better achieved by considering toxic impacts across species. Hexavalent chromium [Cr(VI)] is a marine pollutant and global environmental contaminant. While Cr(VI) has been identified as a human lung carcinogen, health effects in marine species are poorly understood. Little is known about how Cr(VI) might impact humans and marine species differently. This study used a One Environmental Health Approach to compare the cytotoxicity and genotoxicity of particulate Cr(VI) in human and leatherback sea turtle (Dermochelys coriacea) lung fibroblasts. Leatherbacks may experience prolonged exposures to environmental contaminants and provide insight to how environmental exposures affect health across species. Since humans and leatherbacks may experience prolonged exposure to Cr(VI), and prolonged Cr(VI) exposure leads to carcinogenesis in humans, in this study we considered both acute and prolonged exposures. We found particulate Cr(VI) induced cytotoxicity in leatherback cells comparable to human cell data supporting current research that shows Cr(VI) impacts health across species. To better understand mechanisms of Cr(VI) toxicity we assessed the genotoxic effects of particulate Cr(VI) in human and leatherback cells. Particulate Cr(VI) induced similar genotoxicity in both cell lines, however, human cells arrested at lower concentrations than leatherback cells. We also measured intracellular Cr ion concentrations and found after prolonged exposure human cells accumulated more Cr than leatherback cells. These data indicate Cr(VI) is a health concern for humans and leatherbacks. The data also suggest humans and leatherbacks respond to chemical exposure differently, possibly leading to the discovery of species-specific protective mechanisms.