Uranium is a naturally-occurring radioactive element that has been mined
and used for its chemical properties for more than a thousand years. It is
now primarily used as fuel for nuclear reactors that make electricity.
Uranium can be recovered in two ways: by conventional mining of the rock
(ore), or by using strong chemicals to dissolve uranium from the rock that
is still in the ground and pumping it to the surface.
Regardless of how uranium is extracted from rock, the processes leave
behind radioactive waste. For example, the solid radioactive wastes that
are left over from the milling processes are called tailings and the
liquid wastes are called raffinates. Mill tailings and raffinates are
stored in specially designed ponds called impoundments. The tailings
remain radioactive and contain hazardous chemicals from the recovery
process.
Uranium eventually decays to radium. Radium decays to release a
radioactive gas called radon. Open pit uranium milling and in situ mining
sites do not pose a significant radon risk to the public or to miners; the
radon disperses into the atmosphere. In the past, the waste rock produced
by underground and open pit mining was piled up outside the mine. This
practice has caused problems, including on Navajo lands where more than
half of the small, abandoned uranium mines from the middle of the 20th
century and their wastes remain. Wind can blow radioactive dust from the
wastes into populated areas and the wastes can contaminate surface water
used for drinking. Some sites also have considerable groundwater
contamination.
Learn more on the EPA's website
Uranium has a half life of 4.5 billion years, meaning this waste isn't
going anywhere without human intervention. Remediation, or the restoraton
of land and ecosystems to previous health, is a promising solution to the
issue of mining waste. This nuclear legacy is far from over with plans to
transport nuclear waste from all over the United States to New Mexico,
making the state a nuclear waste “destination”.While uranium exists
naturally in the environment, concentrations is certain areas are higher
than background levels due to activities revolving around the nuclear
industry. The nuclear industry relies on a supply of uranium, which is
heavily mined for in the southwest. Uncovered and abandoned mines are
still spread throughout the southwest, making uranium and other metals
freely available to the environment. The environment and communities are
not only threatened by abandoned mines, but also the radioactive waste
that is left at the end of the nuclear fuel chain. A recent study used
quantitative framework to show the association between uranium waste
exposure and chronic illnesses such as kidney disease, diabetes, and
hypertension.
Fungi and mushrooms represent an exciting opportunity to remediate
radioactive contaminants, like uranium. Mushrooms and fungi have the
ability to absorb uranium, therefore removing it from the enviironment.
(1) Herzer, K. Exploring Feminine Science. UNM 2021, 12.
(2) Stamets, P. Mycelium Running; 2005.