Investigating Environmental Contaminants

My name is Anna Shimkus, Whitman class of 2026, and this summer I’m working in the Ingram Analytical Environmental Chemistry Lab at Northern Arizona University. The Ingram Lab focuses mainly on environmental contaminants, and more specifically, uranium contamination. 

Uranium has an extensive history in the four corners region of the southwest, as between the 1940s and the 1980s the Navajo Nation was home to vast amounts of uranium mining for nuclear weaponry. Though these mining sites have been shut down for decades, many of them were abandoned without proper clean up. Due to this, there is significant concern on Navajo Nation regarding uranium contamination in the environment, and the potentially carcinogenic effects of such contaminants. 

I was very excited to start working in the Ingram Lab, as I thought it would be a great way to intertwine my major (Biochemistry, Biophysics, and Molecular Biology or BBMB) with my interests as a Pre-Med student. My main project this summer has been looking at changes in uranium concentration within mutton using different cooking methods. We were specifically 

interested in mutton since it is a traditional food within Navajo Nation and is often prepared as a stew. Preparing mutton in a stew can potentially introduce even more uranium contamination, as water sources on Navajo Nation are not regulated and may have higher concentrations of heavy metals. 

The method of determining uranium concentration in a substance, be it mutton, water, or otherwise, revolves around the use of an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) instrument. In short, the ICP-MS can determine the concentration of an element given it’s specific mass and charge. Since all samples have to undergo a similar preparation process before being analyzed by the ICP-MS, I was able to help with multiple projects all while practicing similar skills. For example, I also helped to collect and prepare samples for a project exploring uranium concentration in top soil on Navajo Nation. 

The majority of my work had to do with preparing samples, as uranium is often found in complex chemical environments which make it difficult to identify in the ICP-MS instrument. This can sometimes be the most dangerous part of the sample preparation, as very strong acids are used to help break apart the chemical compounds where uranium is housed. 

Soil is especially tough, so we used hydrofluoric acid, or HF, to help “digest” the samples. This requires specialized training and personal protective equipment, as exposure to hydrofluoric acid can lead to severe burns and even cardiac arrest. In the following picture I’m training to use HF and wearing specific equipment to protect myself from exposure. 

Sample collection can also sometimes require fieldwork. For the mutton project we were able to source the meat from a local Arizona grocer, but the soil project required that we travel to Cameron, Arizona to collect samples. We traveled specifically to Cameron because it is home to a uranium mound where waste from previous mining now sits less than 100 ft away from a

residential area. Myself and other lab workers wore additional protective equipment, such as gloves and masks, and monitored our radiation exposure with Geiger counters while collecting samples. The following picture shows myself, as well as two other lab workers on top of the uranium mound while collecting samples. 

I’ve had a great time so far learning more about analytical chemistry and bringing the knowledge I’ve gained at Whitman back to my home state. The whole experience has opened my eyes to the various factors that are affecting public health in rural areas across the US, and has further developed my interest in medicine and non-traditional approaches to improving public health. I’m extremely grateful for Dr. Ingram and everyone in the Ingram Lab for being great teachers and for Whitman’s Career and Community Engagement Center for helping make this internship possible!