Quantification of Elemental Contaminants in Unregulated Water across Western Navajo Nation

Credo, Jonathan; Torkelson, Jaclyn; Rock, Tommy; Ingram, Jani C.

doi:10.3390/ijerph16152727

Cited by 42 publications

(45 citation statements)

References 49 publications

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“…Contamination of groundwater from U mining can occur due to erosion of tailing piles and from open pit mining below the water table that produce mine waste water (US EPA 2007). Through increased exposure to water and oxygen, mining activities increase the mobilization of elements such as U and arsenic (As); therefore, the risk of contamination of natural water sources is greater in mining areas (Hoover et al 2017; Credo et al 2019). Arsenic is a natural occurring contaminant that is elevated in groundwater in the southwestern United States due in part to desorption reactions with metal oxides, dissolution reactions, a concentration effect due to high evaporation rates in arid zones, and mining activity (Smedley and Kinniburgh 2002).…”

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confidence: 99%

Dissolved Uranium and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation

Jones

Credo

Parnell

et al. 2020

Contemporary Water Research

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Concentrations of dissolved uranium (U) and arsenic (As) above drinking water standards in unregulated water sources pose various human health risks. Although high natural background concentrations may occur in some environments (Runnells et al. 1992), anthropogenic contamination concerns are especially troublesome on the Navajo Nation (NN), where past U mining activity may have contaminated water supplies. This research investigated U and As groundwater contamination issues in unregulated wells in the western portion of the NN. Objectives of this research were to provide insights to human health risks by assessing the spatial extent and seasonal variability of U and As concentrations while effectively communicating the potential contamination risks to the local Navajo people. Eighty‐two unregulated wells were sampled in 2018; nine of these sources exceeded the maximum contaminant level (MCL) for drinking water standards for U (30 µg/L), and 14 exceeded the MCL for drinking water standards for As (10 µg/L). U and As levels were highest in the southwest portion of the study area and seasonal variability was observed in a subset of wells, especially shallower hand dug wells and hand pumps. The results were compiled into a report that was presented to NN chapters included in the study as well as the Navajo Department of Water Resources and the NN Environmental Protection Agency. Implications for regional water quality patterns can help to direct policy recommendations for well monitoring, water use, and remediation targets.

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confidence: 99%

Dissolved Uranium and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation

Jones

Credo

Parnell

et al. 2020

Contemporary Water Research

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“…[20] On the Navajo Nation, it is reported that 30% of the community consumes unsafe water that is intended for livestock only or has unregulated water sources for drinking purposes. [21] Multiple studies have found elevated levels of metal(loid)s, such as arsenic, cadmium, lead, vanadium, manganese, and uranium on Diné lands, [22][23][24][25][26][27][28] and in human drinking water sources in communities that rely on water for ingestion, cleaning, agriculture, animal husbandry, and cultural needs. [29] Hard rock mining and its' toxicants are only one example, as environmental contamination may occur from other industries (i.e., gas, coal, oil).…”

Section: Watermentioning

confidence: 99%

American Indian/Alaska Native community infrastructure limitations amid the COVID-19 threat

Samuel-Nakamura

Hodge

2021

JNEP

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Objective: The recent SARS-CoV-2 (COVID-19) pandemic that is spreading throughout the nation is a particular threat to American Indian and Alaska Native (AI/AN) communities. The use of recommended methods to prevent or mitigate the spread of the virus, such as hand washing, social distancing, masks, contact tracing and community education is highly problematic at many of these sites. The objective of this paper is to identify and examine structural or cultural barriers to implementing COVID-19 recommendations on select reservation sites.Methods: A qualitative approach that collected and analyzed data from existing sources including newsletter articles, relevant policies and other published reports was instituted in the Spring of 2020. The Centers for Disease Control and Prevention (CDC) policies regarding COVID-19 recommendations to halt the spread of the virus were selected as the standard for COVID-19 prevention, surveillance and mitigation. News articles between March 1, 2020 and December 1, 2020 were identified using various search engines and tribal websites. Information from news resources, including literature reviews, newsletter articles, social media reports, and tribal policy announcements, were gathered and reviewed. Two U.S. southwestern communities are used as examples for the review.Results: Data collected from various sources paint a picture of American Indian communities that lack adequate community infrastructures, and have problems of residential isolation, close living quarters, and contaminated and scarce water supplies. Unsafe or limited water restricts handwashing. Limited informational tools, such as telephone, internet, computer and newsletters, restricted adequate notification of the novel coronavirus to American Indian reservation communities. Often, the lack of a physical home address can create barriers to healthcare accessibility and surveillance, as it limits the identification and access to households. In addition, many traditional cultures of AI/ANs emphasize the interrelatedness of all in nature and thus require an ecological approach to health education and preventive measures, identified as a limitation for COVID-19 surveillance and mitigation.Conclusions: AI/AN communities face a serious threat of contracting COVID-19. Four key infrastructure limitations to effective COVID-19 prevention, surveillance and mitigation were identified: limited access to safe water, deficient telecommunication networks (telephone, internet, and television), housing isolation and shortages, and inadequate medical services – are experienced by many AI/AN communities. Although there are 574 federally recognized tribes in the United States, the two identified in this study subscribe to an ecological approach to health education and preventive measures in that they believe in the interrelatedness of all things in nature. Surveillance questions may be misunderstood or seem invasive and prevention measures (masks, social distancing, and handwashing) may seem to be extreme measures to groups so close to the environment. Together, these present serious barriers to prevention and mitigation of the COVID-19 virus in this underserved population.

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“…Inductively coupled plasma mass spectrometry (adapted from Credo et al 2019) For this study, arsenic levels were quantified at only one time point for each site. We collected two 500 ml water samples from each of the three sites on December 4, 2019 in clean wide-mouth packers (#05-719-149B, Fisher After reduction of arsenate (iAs V ) into arsenite (iAs III ), it is metabolized to monomethylarsonic acid (MMA III or MMA V ) and subsequently to dimethylarsinic acid (DMA III or DMA V ), a less toxic chemical, via methylation by arsenite (+3) methyltransferase (as3mt) and oxidation.…”

Section: Collecting Sitesmentioning

confidence: 99%

Synonymous single nucleotide polymorphism in arsenic (+3) methyltransferase of the Western mosquitofish (Gambusia affinis) and its gene expression among field populations

et al. 2021

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Naturally occurring arsenic is toxic at extremely low concentrations, yet some species persist even in high arsenic environments. We wanted to test if these species show evidence of evolution associated with arsenic exposure. To do this, we compared allelic variation across 872 coding nucleotides of arsenic (+3) methyltransferase (as3mt) and whole fish as3mt gene expression from three field populations of Gambusia affinis, from water sources containing low (1.9 ppb), medium-low (3.3 ppb), and high (15.7 ppb) levels of arsenic. The high arsenic site exceeds the US EPA’s Maximum Contamination Level for drinking water. Medium-low and high populations exhibited homozygosity, and no sequence variation across all animals sampled. Eleven of 24 fish examined (45.8%) in the low arsenic population harbored synonymous single nucleotide polymorphisms (SNPs) in exons 4 and/or 10. SNP presence in the low arsenic population was not associated with differences in as3mt transcript levels compared to fish from the medium-low site, where SNPs were noted; however, as3mt expression in fish from the high arsenic concentration site was significantly lower than the other two sites. Low sequence variation in fish populations from sites with medium-low and high arsenic concentrations suggests greater selective pressure on this allele, while higher variation in the low population suggests a relaxed selection. Our results suggest gene regulation associated with arsenic detoxification may play a more crucial role in influencing responses to arsenic than polymorphic gene sequence. Understanding microevolutionary processes to various contaminants require the evaluation of multiple populations across a wide range of pollution exposures.

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Quantification of Elemental Contaminants in Unregulated Water across Western Navajo Nation

Cited by 42 publications

References 49 publications

Dissolved Uranium and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation

Dissolved Uranium and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation

American Indian/Alaska Native community infrastructure limitations amid the COVID-19 threat

Synonymous single nucleotide polymorphism in arsenic (+3) methyltransferase of the Western mosquitofish (Gambusia affinis) and its gene expression among field populations

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