These advisories are based on samples of fish tissue collected by the Nebraska Department of Environmental Quality and analyzed by the U. S. Environmental Protection Agency laboratory. Omaha Creek at Homer Logan Creek at Lyons. Mercury is a naturally occurring metal, Pour said. Mining and industrial uses are the primary sources of mercury in the environment. Advisories for mercury were previously issued for Skyview Lake in Norfolk, Czechland Lake near Prague, the Little Blue River near Steele City, Liberty Cove Lake, Zorinsky Lake, Wehrspann Lake, Oliver Reservoir, Merritt Reservoir, and Box Butte Reservoir within the last four years and these advisories remain in place.
Advisories issued for PCBs and dieldrin contamination in previous years remain in effect.
Dieldrin is a pesticide of the organochlorine group. Most uses of dieldrin were restricted beginning in 1974, and all commercial sales ended in 1987. Dieldrin is a long-lasting chemical and is persistent in the environment. Advisories for cancer-causing chemicals in fish are issued by the Department of Regulation and Licensure when concentrations reach a risk Level of one in 10,000. This means that, under a worst-case scenario, the chemicals would cause one additional case of cancer per 10,000 people eating those fish on a regular basis.