Science for Decision Making on Uranium Mining in Arizona

Exposure Characterization in Plants and Animals through the Mine Life Cycle

At Arizona 1 Mine

Arizona 1 Mine Life Cycle

Arizona 1 represents conditions after mining, before reclamation.

Vegetation, terrestrial invertebrates, and small rodents were collected for chemical and radiological exposure characterization at

  • Arizona 1 Mine and reference areas in the summer of 2015 (before reclamation ).1
  • Pinenut Mine and reference areas in the summer of 2015 (during active mining).1
  • Pinyon Plain (formerly Canyon) Mine in the summer of 2013 (before mining).2
  • EZ breccia pipes in the summer of 2015 (vegetation only; known uranium-mineralized but undeveloped breccia pipes).
  • Kanab North Mine in 2015 (decades after mining, before reclamation).3


  • We used traditional and new survey tools to understand how mining activities can affect local food webs. Chemicals can enter animals by ingestion, inhalation, absorption, and dietary transfer.1,2,3,4,5,6,7,8
  • Plants and animals take up mining-related radionuclides, uranium, other elements but direct effects were not linked.1,2,3
  • Radiation levels in plants and animals were low. Radiation enters rodents through soil interactions (burrowing, incidental ingestion, bathing, etc.) or their diet. Radium-226 was below protective levels. It is of most concern for rodent health.2,3,8
  • Tadpoles in the mine pond accumulated mining-related chemicals. Arsenic and selenium levels exceed protective thresholds.2



Specific Tasks

Task 5a: Compile/evaluate existing and newly collected monitoring data from various agencies/sources
Task 5c: Collect/analyze samples from biota with focus on trust resources
Task 7a: Conduct species surveys
Task 17: Determine biological effects of uranium + trace element mixtures


1 Cleveland, D., Hinck, J.E., Lankton, J.S., 2021, Elemental and radionuclide exposures and uptakes by small rodents, invertebrates, and vegetation at active and post-production uranium mines in the Grand Canyon watershed: Chemosphere, vol. 263,

2 Hinck, J.E., Cleveland, D., Brumbaugh, W.G., Linder, G., and Lankton, J., 2017, Pre-mining trace element and radiation exposure to biota from a breccia pipe uranium mine in the Grand Canyon (Arizona, USA) watershed: Environmental Monitoring and Assessment, February 2017

3 Cleveland, D.M., Hinck, J.E. and Lankton, J.S., 2019, Assessment of chronic low-dose elemental and radiological exposure of biota at the Kanab North uranium mine site in the Grand Canyon watershed: Integrated Environmental Assessment and Management 15:112-125,

4 Hinck, J.E., Linder, G., Darrah, A.J., Drost, C.A., Duniway, M.C., Johnson, M.J., Mendez-Harclerode, F.M., Nowak, E.M., Valdez, E.W., Wolff, S., and van Riper III, C., 2014, Exposure pathways and biological receptors--Baseline data for the Canyon Uranium Mine, Coconino County, Arizona: Journal of Fish and Wildlife Management, v. 5, no. 2, p. 422-440

5 Klymus, K.E., Richter, C.A., Thompson, N., and Hinck, J.E., 2017, Metabarcoding of Environmental DNA Samples to Explore the Use of Uranium Mine Containment Ponds as a Water Source for Wildlife: Diversity 2017, v. 9, no. 4.

6 Valdez, E.W., Hanttula, M.K., and Hinck, J.E. 2021. Seasonal activity and diets of bats at uranium mines and adjacent areas near the Grand Canyon. Western North American Naturalist: Vol. 81 :1-18,

7 Mann, R.K., Duniway, M.C., 2020, Vegetation cover and composition data in environments surrounding uranium mines in the Grand Canyon ecosystem, U.S. Geological Survey data release,

8 Minter, K.M., Jannik, G.T., Hinck, J.E., Cleveland, D., Kubilius, W.P.,and Kuhne, W.W., 2019, Biota dose assessment of small rodents sampled near breccia pipe uranium mines in the Grand Canyon watershed: Health Physics 117:20-27