Elemental and radionuclide exposures and uptakes by small rodents, invertebrates, and vegetation at active and post-production uranium mines in the Grand Canyon watershed

The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized exposure biota to co-occurring ore body elements during active production at a site where had recently concluded. Our results indicate that have taken up other (e.g., arsenic, cadmium, copper, molybdenum, uranium) from surficial contamination, like blowing dust. Results potential for prolonged radionuclides upon conclusion production. Mean radium-226 deer mice was 4 times greater than uranium-234 uranium-238 those same samples; this may for, but does not necessarily imply, toxicity. Soil screening benchmarks molybdenum toxicity thresholds selenium, growth effects) were exceeded vegetation, invertebrates, rodents (Peromyscus spp., Thomomys bottae, Tamias dorsalis, Dipodomys deserti). However, prevalence severity microscopic lesions rodent tissues (as direct evidence biological uptake exposure) could be definitively linked mining. data land managers might consider factors species, seasonal changes environmental concentrations, bioavailability, when determining mine permitting remediation watershed. Ultimately, our will useful site-specific risk analysis can support future decisions regarding mineral extraction withdrawal elsewhere.