Living with Environmental Contaminants

Ms. Amy Chandos, M.S. – Amy Chandos received her Bachelor of Science degree in  Evolution, Ecology & Biodiversity from the University of California, Davis in 2010 and her  master’s degree in Biology from Northern Arizona University (NAU) in 2017. Her master’s  thesis investigated the effects of temperature on swimming performance of three species of fish  found in the Colorado River Basin. She found that swimming performance improved as  temperature increased up to the thermal tolerance of the species. Additionally, fish acclimated to  higher temperatures required greater amounts of food and had a lower mass-to-length ratio than  cooler temperatures, indicating that they were under a greater physiologic stress. She is current a  senior research technician and collaborates with Jonathan on a wide variety of projects. In this  role she assists in instrumental analysis, sample preparation, field work management, and is the primary supervisor for all fish that are used in the related experiments. Amy has more than 12  years of experience in fish care and husbandry, field work and ecology, and project management.  

Mr. Jonathan Credo (Navajo), MD/PhD Student – Jonathan Credo received two Bachelor of  Science degrees from Northern Arizona University in 2014, one in Chemistry with an emphasis  in Biochemistry, ACS Certified, and another in Biomedical Science. He started his MD/PhD training at the University of Arizona College of Medicine in 2015. His dissertation research  focuses on the health impacts of environmental contaminant exposure in minority and tribal  populations in Yuma County, AZ. Upon completion of his degree, Jonathan intends to pursue a  research career understanding how environmental pollutants impact health outcomes especially  in minority and tribal populations. In addition to his dissertation work, Jonathan collaborates on  numerous projects that assess the impacts of environmental contaminants. This work includes  projects in Israel and Latin America, to projects within the Navajo Nation where he has worked  with some communities for more than ten years. He has more than ten years of experience in  instrumentation and collaboration with tribal and minority communities and three years of  clinical medicine experience in rural and tribal communities.  

Jonathan Credo CIEHR

JMIR Research

This week, we speak with Jonathan Credo, an MD-PhD student at the University of Arizona College of Medicine, and Amy Chandos, a senior research technician at Northern Arizona University. We discuss the impacts of human-caused contamination on tribal communities, non-native communities, and ecosystems.

Science Moab: What kinds of contaminants do you study?

Credo: Most of the contaminants are human-caused. In southern Utah, there’s a lot of agriculture, so contaminants could be runoff from farms or livestock. These aren’t necessarily intentional or malicious; we’re only recently understanding how chemicals make their way through groundwater and soils. 

Another significant source of contamination is the long history of heavy metal mining in the Southwest. The Navajo Nation is infamous for its long history of uranium mining. But even before uranium mining picked up, this region had been mined for things like vanadium, molybdenum, and other precious heavy metals. 

Science Moab: How do these pathways of human exposure happen?

Credo: One way is exposure through ingestion, so things that people eat, drink, or inhale. But then we need to break it down. We need to understand where the contaminants are stored.

Mining can contribute to both those latter pathways. As you dig into the earth, you have the potential to contaminate the groundwater system, or even spill into surface water. As for inhalation exposure, if you’re digging in a dusty environment, you’re going to have to move the dirt you displaced. While that dirt might not have the resources you’re after, it can certainly be enriched by other contaminants, like arsenic and manganese.

Science Moab: Once these things enter the system, how long are effects felt?

Chandos: It depends on the chemical element. A lot of hydrophilic contaminants can be transient as long as the source goes away, but if there’s a continual source, then there’s going to be continual exposure.

Credo: I think effects are much longer than a lot of people realize. The Gold King Mine spill is an excellent example; there’s a rather infamous photo of the river dyed gold, but within a week or month, the water went back to roughly the previous color.

If you look at just that system, and have a relatively narrow scope, then water contaminants do tend to cycle out fairly quickly. But the governing thought now is that contaminants likely accumulate in reservoirs downstream, almost like drip coffee. That can be scary for the communities that live downriver.

Science Moab: Could you break down the distribution of contaminants on the Plateau?

Credo: The short answer is that we’re not sure. We certainly see a higher incidence of certain cancers and chronic health diseases in tribal people on the Colorado Plateau. But this is a common problem with contamination science: is this because of the toxic environment they live in, or because of other health disparities? It’s hard to suss out those variables. But the fact that this is unknown should not be an excuse not to study it; the fact that these studies are difficult should not be a reason to not look into it.

Chandos: Sometimes scientists have difficulty working with the tribes and minority groups. There can be a lot of distrust, because scientists in the past haven’t always operated with the best interests of these people in mind. They definitely have not always been culturally sensitive. That has not helped data gathering and information dissemination, either.

Science Moab: What things can start to address these environmental exposures on the Plateau?

Credo: One message is not to get discouraged. Most scientists are more than happy to talk with the community. Without community buy-in, our research is just going to rot away in a publication or on someone’s shelf. If the community becomes educated and involved, then they can make their voices known among local representatives. On the long-term scale, you can achieve larger policy changes.

Chandos: That legislation has also allowed for the cleanup of many contamination sources, including mines, mine tailings, and environmental spills, like the Gold King Mine spill. These cleanups are aiming to help the ecosystem and animals thrive in this environment that is heavily influenced by people.

Science Moab is a nonprofit dedicated to engaging community members and visitors with the science happening in Southeast Utah and the Colorado Plateau. To learn more and listen to the rest of Jonathan Credo and Amy Chandos’s interview, visit www.sciencemoab.org/radio. This interview has been edited for clarity.