Anita L. Moore-Nall

Landfill contaminants pose significant risks to environmental and human health, particularly in rural Alaska. These communities are predominantly Alaska Native and face unique challenges in solid waste management due to geography, climate, and limited infrastructure. This scoping review assessed published research on the impacts of landfill contaminants in the Arctic (Aim 1) and Alaska specifically (Aim 2). Seventy-one studies met the inclusion criteria, all of which were used to develop a conceptual model of contaminant transport pathways. Thirty-nine studies included Alaska-specific research: thirty-three focused on environmental impacts, and six addressed human health (e.g., birth outcomes, cancer). Key topics included waste burning, heat generation, carbon release, leachate characterization, and water or sediment contamination. Evidence specific to Alaska suggested landfill leachate may contaminate surface water and groundwater, and that microbes can migrate beyond the landfill site boundaries in communities using honeybuckets (plastic bag-lined buckets that collect human waste). Landfill contaminants also impacted wildlife through consumption of garbage, which may have human health implications for subsistence-based communities. Major research gaps remain in understanding individual-level exposures, the effects of emerging contaminants, and the mechanisms of contaminant transport pathways. Further research designed for causal inference is needed to support improvements to public and environmental health.

Calcified eggshells protect developing embryos against environmental stress and contribute to reproductive success¹. As modern crocodilians and birds lay hard-shelled eggs, this eggshell type has been inferred for non-avian dinosaurs. Known dinosaur eggshells are characterized by an innermost membrane, an overlying protein matrix containing calcite, and an outermost waxy cuticle^2,3,4,5,6,7. The calcitic eggshell consists of one or more ultrastructural layers that differ markedly among the three major dinosaur clades, as do the configurations of respiratory pores. So far, only hadrosaurid, a few sauropodomorph and tetanuran eggshells have been discovered; the paucity of the fossil record and the lack of intermediate eggshell types challenge efforts to homologize eggshell structures across all dinosaurs^{8,9,10,11,12,13,14,15,16,17,18}. Here we present mineralogical, organochemical and ultrastructural evidence for an originally non-biomineralized, soft-shelled nature of exceptionally preserved ornithischian Protoceratops and basal sauropodomorph Mussaurus eggs. Statistical evaluation of in situ Raman spectra obtained for a representative set of hard- and soft-shelled, fossil and extant diapsid eggshells clusters the originally organic but secondarily phosphatized Protoceratops and the organic Mussaurus eggshells with soft, non-biomineralized eggshells. Histology corroborates the organic composition of these soft-shelled dinosaur eggs, revealing a stratified arrangement resembling turtle soft eggshell. Through an ancestral-state reconstruction of composition and ultrastructure, we compare eggshells from Protoceratops and Mussaurus with those from other diapsids, revealing that the first dinosaur egg was soft-shelled. The calcified, hard-shelled dinosaur egg evolved independently at least three times throughout the Mesozoic era, explaining the bias towards eggshells of derived dinosaurs in the fossil record.

An estimated 11 million people in the US have home wells with unsafe levels of hazardous metals and nitrate. The national scope of the health risk from consuming this water has not been assessed as home wells are largely unregulated and data on well water treatment and consumption are lacking. Here, we assessed health risks from consumption of contaminated well water on the Crow Reservation by conducting a community-engaged, cumulative risk assessment. Well water testing, surveys and interviews were used to collect data on contaminant concentrations, water treatment methods, well water consumption, and well and septic system protection and maintenance practices. Additive Hazard Index calculations show that the water in more than 39% of wells is unsafe due to uranium, manganese, nitrate, zinc and/or arsenic. Most families’ financial resources are limited, and 95% of participants do not employ water treatment technologies. Despite widespread high total dissolved solids, poor taste and odor, 80% of families consume their well water. Lack of environmental health literacy about well water safety, pre-existing health conditions and limited environmental enforcement also contribute to vulnerability. Ensuring access to safe drinking water and providing accompanying education are urgent public health priorities for Crow and other rural US families with low environmental health literacy and limited financial resources.

The origin of V, U, REE and other metals in the Permian Phosphoria Formation have been speculated and studied by numerous scientists. The exceptionally high concentrations of metals have been interpreted to reflect fundamental transitions from anoxic to oxic marine conditions. Much of the oil in the Bighorn Basin, is sourced by the Phosphoria Formation. Two of the top 10 producing oil fields in Wyoming are located approximately 50 km west of two abandoned U-V mining districts in the northern portion of the basin. These fields produce from basin margin anticlinal structures from Mississippian age reservoir rock. Samples collected from abandoned U-V mines and prospects hosted in Mississippian aged paleokarst in Montana and Wyoming have hydrocarbon residue present and contain anomalous high concentrations of many metals that are found in similar concentrations in the Phosphoria Formation. As, Hg, Mo, Pb, Tl, U, V and Zn, often metals of environmental concern occur in high concentrations in Phosphoria Formation samples and had values ranging from 30–1295 ppm As, 0.179–12.8 ppm Hg, 2–791 ppm Mo, <2–146 ppm Pb, 10–490 ppm Tl, 907–86,800 ppm U, 1240–18,900 ppm V, and 7–2230 ppm Zn, in mineralized samples from this study. The REE plus Y composition of Madison Limestone- and limestone breccia hosted-bitumen reflect similar patterns to both mineralized samples from this study and to U.S. Geological Survey rock samples from studies of the Phosphoria Formation. Geochemical, mineralogical and field data were used to investigate past theories for mineralization of these deposits to determine if U present in home wells and Hg content of fish from rivers on the proximal Crow Indian Reservation may have been derived from these deposits or related to their mode of mineralization.

Exposure to uranium can damage kidneys, increase long term risks of various cancers, and cause developmental and reproductive effects. Historically, home well water in Montana has not been tested for uranium. Data for the Crow Reservation from the United States Geological Survey (USGS) National Uranium Resource Evaluation (NURE) database showed that water from 34 of 189 wells tested had uranium over the Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) of 30 μg/L for drinking water. Therefore the Crow Water Quality Project included uranium in its tests of home well water. Volunteers had their well water tested and completed a survey about their well water use. More than 2/3 of the 97 wells sampled had detectable uranium; 6.3% exceeded the MCL of 30 μg/L. Wells downgradient from the uranium-bearing formations in the mountains were at highest risk. About half of all Crow families rely on home wells; 80% of these families consume their well water. An explanation of test results; associated health risks and water treatment options were provided to participating homeowners. The project is a community-based participatory research initiative of Little Big Horn College; the Crow Tribe; the Apsaalooke Water and Wastewater Authority; the local Indian Health Service Hospital and other local stakeholders; with support from academic partners at Montana State University (MSU) Bozeman.

Uranium occurrence and development has left a legacy of long-lived health effects for many Native Americans and Alaska Natives in the United States. Some Native American communities have been impacted by processing and development while others are living with naturally occurring sources of uranium. The uranium production peak spanned from approximately 1948 to the 1980s. Thousands of mines, mainly on the Colorado Plateau, were developed in the western U.S. during the uranium boom. Many of these mines were abandoned and have not been reclaimed. Native Americans in the Colorado Plateau area including the Navajo, Southern Ute, Ute Mountain, Hopi, Zuni, Laguna, Acoma, and several other Pueblo nations, with their intimate knowledge of the land, often led miners to uranium resources during this exploration boom. As a result of the mining activity many Indian Nations residing near areas of mining or milling have had and continue to have their health compromised. This short review aims to rekindle the public awareness of the plight of Native American communities living with the legacy of uranium procurement, including mining, milling, down winders, nuclear weapon development and long term nuclear waste storage.