Abstract

Selenium, an element required in trace quantities for normal health of animals and humans, can cause problems for livestock, wildlife, and humans when ingested in larger-than-required concentrations. It is present in many sedimentary deposits and in arid, alkaline soils typical of the western United States, selenium can be mobilized or released from soil by irrigation and may reach hazardous concentrations in drainage water. If water containing selenium enters a wetland or pond, biological processes can magnify the concentration within wildlife and cause reduced reproduction and deformities. Within the middle Green River area of Utah, large concentrations of selenium have been found in water and wildlife at Stewart Lake Waterfowl Management Area and at Ouray National Wildlife Refuge. Several other areas of the State are affected to a lesser degree. Human consumption of fish and fowl from contaminated areas could result in selenium dosages that exceed the recognized safe and adequate maximum daily intake of 200 micrograms. Options for remedial action for contaminated areas involve changes in management of water, drainage, land-use, wildlife, and possible application of waste-water treatment processes.