You may have never, before now, heard of a zebrafish, but this is one aquatic animal you should remember. Why? Because it may help wellness experts to gain a better understanding of environmental wellness, and how chemicals in the atmosphere and in your products are impacting your health and wellbeing. This is according to researchers at a lab at Oregon State University, led by professor of molecular toxicology Robert Tanguay, who are using zebrafish to assess the impacts of multiple chemical exposures.
When it comes to the use of zebrafish in toxicology, Tanguay is a pioneer. His lab is on the cutting edge of this research, designing the new equipment and techniques that scientists need to examine the impacts of multiple chemical exposures. Why is this important? With zebrafish, scientists can soon determine why certain chemical components of crude oil spilled by the Exxon Valdez in 1989 continue to negatively affect fish survival in Alaska’s Prince William Sound. As well as this, zebrafish are enabling Tanguay and other scientists to zero in on why pesticide runoff can impair Pacific Northwest salmon’s ability to navigate, and how oil from the ruptured Deepwater Horizon well is affecting marine species’ health in the Gulf of Mexico.
However, Elizabeth Grossman, author of Chasing Molecules: Poisonous Products, Human Health, notes that zebrafish research goes well beyond the impact of chemical exposures on marine life. ‘Zebrafish studies are also being used to assess the potential human health impacts of the chemical stew in US Superfund sites,’ she details. ‘Zebrafish are also proving key to advancing our understanding of how particular chemical compounds affect the expression of individual genes that maintain and influence virtually every body system.’ Tanguay notes, ‘Some people are still sceptical about how a fish can model human health, but during early development we are more similar to fish than at any other time in life.’ Grossman explains, ‘Genes are particularly susceptible to environmental chemicals in early development. What happens then can set the stage for health throughout the rest of life.’
Moreover, Tanguay’s team are evaluating the exposure of multiple chemicals, when, historically, chemicals have been evaluated and regulated one at a time. In reality, however, we are exposed to a variety of chemicals daily throughout our lives. Therefore, it’s urgently important to understand how mixtures may affect human health, we now know that environmental chemical exposure can profoundly influence the development of disease. As Linda Birnbaum, director of the US National Toxicology Program and the National Institutes of Environmental Health Science (NIEHS), puts it, ‘We live in a chemical soup.’ So, why bother looking at one ingredient at a time?
Using zebrafish in scientific research is no new thing; since the 1990s, the small, white and silver striped creatures have been used for genetic modelling and screening. However, it was Tanguay, while working as a post-doctoral fellow in 1995, who suggested they might be used in toxicology. Grossman enthuses, ‘Because they are vertebrates, these prolifically reproducing fish turn out to be an extremely useful model for understanding how cells in other vertebrates, including humans, respond to environmental chemicals. Zebrafish, which progress from a translucent egg to a recognizable baby fish in just 24 hours, are ideal for investigating how chemicals may affect biological processes at various stages of development.’
So what’s the long-term aim for these fishy friends to environmental research? ‘The ultimate goal is to learn which chemical combinations, concentrations, and structures alter the normal function of genes and hormones,’ Grossman comments. ‘There is strong evidence, for example, that interference with endocrine system hormones and the genes that regulate them can lead to metabolic disorders such as diabetes and obesity. Research has also shown that endocrine-disrupting chemicals can upset reproductive, developmental, immune system, and neurological health…In a world where manufactured chemicals are ubiquitous, the tiny, fecund zebrafish is playing a big role in discovering how this chemical stew is affecting our health.’