Uranium in Water: Pollution from Uranium Mining
Uranium is a naturally occurring heavy metal used in nuclear power generation, atomic weapons and nuclear medicine applications. It occurs in trace amounts in our air, water and soil, and in more concentrated amounts in rock formations that can be mined. According to the Canadian Coalition for Nuclear Responsibility (CCNR), much of the world’s uranium is mined in Canada. Because uranium and the byproducts of uranium production are highly radioactive, uranium in water, air and soil poses serious concerns for the environment and human health.
As uranium is exposed through mining, radioactivity is released from the rock and begins to decay. According to the U.S. Environmental Protection Agency, radon gas is the largest pollutant, followed by its by-products, called “daughters”: thorium, radium, polonium and lead. Sulfuric acid is used to leach uranium out of the ore. Like coal mining, uranium mining also produces high concentrations of arsenic.
Uranium Mining and Water Use
Approximately one ton of ore must be pulverized to produce two pounds of uranium. Vast amounts of water are used to keep dust down in the mines. Nuclear Free Queensland reports that one Australian mine uses up to 42 million liters of water per day. The residue, called tailings, remains dangerously radioactive for millions of years. The Canadian Coalition for Nuclear Responsibility notes that tailings were once used in the construction of schools and homes until dangerous levels of radon gas were detected. Today, tailings are often stored in open pits, or buried in closed uranium mine shafts, and abandoned. Uranium in water is left to evaporate in retention ponds.
Because radon gas is much heavier than air, it travels low to the ground on the breeze. Rain washes through it, which leads to more uranium in water being deposited on vegetation and agricultural crops. The same rain falls on the surfaces of ponds, lakes and streams, leading to more uranium in water. The toxins make their way into every part of the food chain, ending in humans who consume animals and vegetables for food. As the water evaporates from the sludge-filled retention ponds of uranium mines, toxic dry material remains. Exposed to rain and flooding over time, vast quantities of these toxins are released into the environment. Water in contact with abandoned or closed mines leaches into the water table, moving into watersheds, streams, reservoirs and the drinking water supply.