Data show overall decrease in river and stream contaminants
TOPEKA -- The Kansas Department of Health and Environment (KDHE) and the Kansas Department of Wildlife and Parks (KDWP) have issued fish consumption advisories for 2007. The advisories identify species of fish that should be eaten in limited quantities, or in some cases, avoided altogether because of contamination found in tested fish. The advisories include guidelines for mercury and polychlorinated biphenyls (PCBs) in fish, perchlorate in fish and other aquatic life, and lead and cadmium in shellfish.

Trend data from most Kansas long-term monitoring sites show a decrease in mercury and PCBs. PCBs have not been in use in the U.S. since the 1970s, and chlordane use was discontinued in 1988. Chlordane levels have declined dramatically statewide, and PCB levels are expected to follow. PCBs and chlordane degrade slowly, so it takes decades for them to be completely removed from the environment, even after use is discontinued.

The two agencies recommend not eating specified fish or aquatic life from the following locations for the reasons stated:

  • the Kansas River from Lawrence (below Bowersock Dam) downstream to Eudora at the confluence of the Wakarusa River for bottom-feeding fish (carp, blue catfish, channel catfish, flathead catfish, freshwater drum, bullheads, sturgeons, buffalos, carpsuckers, and other sucker species) because of PCB levels;
  • Horseshoe Lake located in units 22 and 23 of the Mined Lands Wildlife Area (Cherokee County) for all forms of aquatic life, including all fish, because of perchlorate levels;
  • the Spring River from the confluence of Center Creek to the Kansas-Oklahoma border (Cherokee County) for shellfish (mussels, clams, and crayfish) because of lead and cadmium levels; and
  • Shoal Creek from the Missouri-Kansas border to Empire Lake (Cherokee County) for shellfish because of lead and cadmium levels.

In addition, the agencies recommend a limit of one 8-ounce serving per month, or twelve 8-ounce servings per year, on the consumption of bottom-feeding fish from the following locations due to PCBs:

  • the Arkansas River from the Lincoln Street Dam in Wichita downstream to the confluence with Cowskin Creek near Belle Plaine (Sedgwick and Sumner counties); and
  • Cow Creek in Hutchinson and downstream to the confluence with the Arkansas River (Reno County).

Due to the average levels of mercury, a limit of one 8-ounce serving per week for adults or one 4-ounce serving per week for children 12 years of age or younger is recommended for any species of fish from the following locations:

  • the Little Arkansas River from the Main Street Bridge immediately west of Valley Center to the confluence with the Arkansas River in Wichita (Sedgwick County); and
  • the main stem of the Blue River from U.S. 69 Highway to the Kansas-Missouri state line (Johnson County).

The Environmental Protection Agency (EPA) has issued a national fish consumption advisory for mercury that recommends consuming no more than one 8-ounce serving per week of non-commercial (locally caught) fish. EPA bases this on nationwide average mercury levels in various species of fish but recommends first consideration be given to local advisories. Women who are pregnant or breast feeding should avoid eating large-sized predatory fish such as largemouth bass, or consult their physician. Additional testing for contaminants in fish and other aquatic life will continue on an annual basis.

The advisories assess cancer risk levels using EPA methods. Cancer risk assessment is a method to determine the added increase in cancer levels in a population if fish in the advisory areas are consumed regularly over a 70-year period. Assessments that estimate the increased risk of cancer as greater than one in 100,000 are determined to be unacceptably high-risk levels. Risk assessments for contaminants assessed as non-carcinogens (mercury, lead, and cadmium) are based on 8-ounce servings for adults and 4-ounce servings for children nine to 18 years of age.

For more information, contact the KDHE at 785-296-5571.