What are we studying? | Why are we studying? | What are we finding? | What does it mean? | Where can I read more?
What are we studying?
We study sea turtles including hawksbill sea turtles (Eretmochelys imbricate) and leatherback sea turtles (Dermochelys coriacea) in the ‘One’ environmental health approach to gain an overview of global health investigating the health of humans, wildlife, and ecosystem health. All sea turtle species are endangered and can provide insight into global health as a wildlife species. Leatherback sea turtles are large, and long-lived species that spends almost their entire life in the ocean where they may be exposed to environmental contaminants. Hawksbills are also long lived and their habitat spans many of the oceans like the leatherbacks. Thus, we use these species as models to understand the threat of metal pollution to them, to monitor the health of the oceans, and to understand human health. To accomplish this we employed several methods: 1) We collect turtle tissue samples to measure metal levels including chromium. 2) We establish primary cell lines to measure chromium induced cell death and genetic changes and compare those outcomes to the same endpoints in human and other wildlife species cell lines. 3) We measure DNA and chromosome damage in fresh turtle samples to determine if damage occurs in the individual and to monitor the population.
Why are we studying it?
Reptiles are among the first species to be affected by changes in the environment and so serve as an important study subject to monitor the health of the environment. Sea turtles may experience prolonged exposures to environmental contaminants such as chromium (VI) which is a ubiquitous global contaminant of the marine environment primarily as a result of human activities. While chromium (VI) has been identified as a known human carcinogen, the health effects in marine species are poorly understood. Furthermore, metal levels have been previously investigated in sea turtle species, but these studies are limited and the effects of these exposures remain to be determined. We aim to identify the risk of environmental contaminant to the sea turtle populations and determine if sea turtles can serve as indicators of the threat of environmental contaminants to human health.
What are we finding?
Our assessment of metals and DNA damage in the sea turtles is still underway and we do not have data to report. However, we have found in an initial study of hawksbill sea turtle cell lines that both particulate and soluble forms of chromium (VI) induce cell death and damage chromosomes in hawksbill skin cells. We have found chromium (VI) induces a similar level of cell death, DNA damage, and chromosome damage in treated leatherback and hawksbill cells comparable to human cells. These outcomes support the possibility that chromium may cause reproductive and developmental issues in the turtles and may cause turtle lung cancer.
What does it mean?
Our data support the suggestion that chromium (VI) poses a potential health risk to turtles who are exposed to it through either inhalation of chromium (VI) or other routes such as diet. Furthermore, because our data indicate that chromium damages chromosomes, chromium exposure may contribute to the development of cancer, developmental abnormalities and failure to reproduce.
Where can I read more?
- Wise, S.S., Xie, H., Fukuda, T., Thompson, W.D. and Wise, Sr., J.P. Hexavalent Chromium Is Cytotoxic and Genotoxic to Hawksbill Sea Turtle Cells. Toxicology and Applied Pharmacology, 279: 113–118, 2014. PMID: 24952338. PMCID: PMC4134996.
- Young, J.L., Wise, S.S., Xie, H., Zhu, C., Fukuda, T., and Wise, Sr., J.P. Comparative Cytotoxicity and Genotoxicity of Soluble and Particulate Hexavalent Chromium in Human and Hawksbill Sea Turtle (Eretmochelys imbricate) Skin Cells. Comparative Biochemistry and Physiology, Part C, 178 145–155, 2015. PMID: 26440299. PMCID: PMC4669981.