T133 Environmental Impact Studies for Energy Geology

Monday, 23 October 2017
1:30 PM - 5:30 PM
Room 602/603

ELEVATED URANIUM AND LEAD LEVELS IN THE NAVAJO NATION AT CLAIM 28

Paper number: T133-10
Program: Technical Sessions
Time: 3:45 PM – 4:00 PM

Authors

Abstract

In the late 1940s, the US government incentivized a ‘uranium rush’ to obtain material needed for nuclear weapons production. The uranium-rich land of the Navajo Nation was stripped of its precious resources, and the sites were abandoned without proper remediation by mining companies. This led to contamination of the Navajo lands and waterways where residents lack the funding, education, and resources to identify and decontaminate polluted areas.

The Blue Gap-Tachee Chapter of the Navajo Nation in Blue Gap, Arizona, is home to many of these abandoned uranium mines. The largest abandoned uranium mine in the Blue Gap-Tachee Region, Claim 28, produced around 4,181 tons of uranium during the 1950s and 60s. Remediation consisted of piling all the radioactive mine waste in a large heap and fencing it off. This poses a continued health concern, particularly to the people living in the houses within one mile of the claim. Local residents have tried to get the Federal government to remediate the site but have no scientific data for corroboration.

In this study, both bulk and leachates for soil samples from areas adjacent to Claim 28 were analyzed for uranium (U) and lead (Pb) concentrations. The concentrations of contaminants such as U are compared to the North American Shale Composite (NASC), which represents abundances typical of natural geological background, and the former are higher than other areas around uranium mines in Arizona. In comparison, the labile (leachate) fraction of the soil samples yielded much higher abundances of U and Pb (up to ~500 ppm and ~150, respectively), and clearly demonstrates that these mine-related, anthropogenic components are loosely bound within the soil. Current work is focused on measuring uranium and lead isotope ratios of the soil leachates to determine if these contaminants originated from the Claim 28 mine.

Our results obtained thus far indicate that people located in the area surrounding Claim 28 are living with elevated U and Pb levels in their soil and that it is predominantly mobile.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-305530

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