Abstract

The concept of ‘one’ environmental health posits that humans, animals, and the ecosystem share a common environment and, therefore, what affects the health of one impacts the health of all. However, while toxicological impacts on human health are readily investigated, toxicological-impact studies in wildlife and the ecosystem are lacking. We have been pioneering a ‘One Environmental Health’ approach in metal toxicology using the Sea of Cortez as one area of focus. Our efforts considered two different periods of time. The first time period was in 1999 and was part of a global voyage focused on the sperm whale (Physeter macrocephalus). The second time period started in 2016 and is part of an ongoing series of voyages focused on the Sea of Cortez. It considers six different species of whales. We collected skin biopsies and measured the concentrations of essential metals, selenium, and nonessential metals of toxic concern in the skin. In 1999, sperm whale skin had elevated levels of aluminum and chromium. Metal levels were similar when stratified by gender. Age could not be considered as there were no discernable differences in age and all individuals were adult animals. In general, metal levels in whales from the Sea of Cortez were lower than other parts of the globe. Samples from the recent voyages (2016–2017) are currently being analyzed and results are pending. We next focused on the toxicological effects of chromium in whale skin cells. Using cells from whale species found in the Sea of Cortez, including sperm whales, fin whales (Balaenoptera physalus), blue whales (Balaenoptera musculus) and humpback whales (Megaptera novaeangliae), we investigated the cytotoxic and genotoxic effects of Cr(VI) in whale skin fibroblasts. We measured cytotoxicity with a clonogenic survival assay and genotoxicity by the induction of chromosome aberrations. Cr(VI) induced concentration-dependent increases in cytotoxicity and genotoxicity, indicating that Cr(VI) is toxic to whale cells. Interestingly, comparing the effects in whale cells to those in human cells revealed whales may be more resistant to the genotoxic effects of Cr(VI). Thus, using a One Environmental Health approach, whales, like humans, are exposed to chromium at concentrations of toxicological concern; however, whales may have evolved protective mechanisms against Cr(VI) toxicity.

* Presenting author