Uranium mining Environmental Issues

BOX 6.5
Ecological Effects Possible from Chemical Spills

The following chemicals used in uranium processing have the potential to affect ecological health if significant quantities are spilled:

Sulfuric acid. Sulfuric acid poses moderate acute and chronic toxicity to aquatic life. Exposure may cause superficial burns and lesions on animals. Although small quantities may be neutralized, larger amounts may affect water pH levels, causing acidic conditions. Acidic conditions may promote leaching of other compounds, such as aluminum and iron, from soils (DSEWPC, 2011).

Sodium hydroxide. Although sodium hydroxide is not directly toxic to aquatic life, large enough amounts may cause water pH to rise above the tolerance limits of some freshwater aquatic species (California EPA, 2003).

Carbonate and bicarbonate. Carbonate and bicarbonate are not inherently toxic compounds, but elevated levels may cause indirect negative effects on an aquatic system by raising water pH (Lottermoser, 2010).

Ammonia. At a low pH and temperature, ammonia combines with water to produce ammonium and a hydroxide ion, which is nontoxic. Above pH 9, unionized ammonia is predominant and can readily cross cell membranes, allowing ammonia to accumulate in organisms. Exposure to ammonia at high levels may cause increased respiratory activity and increased heart rate in fish. In addition, exposure can lead to reduction in hatching success, reduced growth and morphological development, and injury to gill tissue, liver, and kidneys. Impacts such as hyperplasia of the gill lining in salmon fingerlings and bacterial gill disease have been seen at even slightly increased levels of ammonia (0.002 mg/L for 6 weeks). Various fish species can die at concentrations of 0.2 to 2.9 mg/L, with trout being the most susceptible and carp the least (CSREES NCWQP, 1976).

Decanol. Decanol biodegrades readily and is expected to adsorb to suspended solids in water and sediment. There is a moderate potential for decanol to bioconcentrate in aquatic organisms. Decanol poses a slight to moderate toxicity to freshwater fish and a moderate toxicity to saltwater fish.

Kerosene. Kerosene spills could result in potential acute toxicity to some forms of aquatic life. The lighter, more volatile compounds of kerosene, such as benzene, toluene, and xylene, could cause long-term contamination hazards to the groundwater. The polycyclic aromatic hydrocarbon compounds in kerosene may be translocated and accumulated in plants. Chronic effects of exposure to some constituents in kerosene include changes in liver; harmful effects on kidneys, heart, lungs, and nervous system; increased rates of cancer; and immunological, reproductive, fetotoxic, and genotoxic effects (Irwin et al., 1997).

processes responsible for acid mine drainage from coal mines in the eastern United States. Biological data are not available for most of these sites. However, information on the effects of acid drainage on stream fish communities and on the recovery of fish communities following remediation is available from studies performed at the Rum Jungle uranium mine site in Australia. The Rum Jungle