Data show decrease in most contaminants of concern
TOPEKA — The Kansas Department of Health and Environment (KDHE) and the Kansas Department of Wildlife and Parks (KDWP) have issued revised fish consumption advisories for 2010. The advisories identify types of fish that should be eaten in limited quantities or, in some cases, avoided altogether because of contamination found in tested fish.

The advisories are based on mercury and polychlorinated biphenyls (PCBs) in fish, and lead and cadmium in shellfish. Data from most long-term monitoring sites show a decrease in PCB levels and no significant change in mercury concentrations. Although PCBs have not been produced in the U.S. since the 1970s, these compounds degrade slowly and take decades to completely break down.

The state recommends not eating specified fish or aquatic life from the following locations:

  1. Kansas River from Lawrence (below Bowersock Dam) downstream to Eudora at the confluence of the Wakarusa River (Douglas and Leavenworth counties) 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;
  2. 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;
  3. 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
  4. Shoal Creek from the Missouri/Kansas border to Empire Lake (Cherokee County) for shellfish because of lead and cadmium levels.

In addition, the state recommends 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:

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

Due to mercury contamination, the state recommends a limit of one 8-ounce serving per week for adults or one 4-ounce serving per week for children (12 years or younger) of predatory fish (basses, crappie, walleye) from the following locations of the Little Arkansas River and of any species of fish from the following locations of the Blue River:

  1. 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
  2. the main-stem of the Blue River from U.S. 69 Highway to the Kansas/Missouri state line (Johnson County).

Kansas counties with current fish consumption advisories include Cherokee, Douglas, Johnson, Leavenworth, Reno, Sedgwick, and Sumner.

In 2004, the Environmental Protection Agency (EPA) issued a nationwide consumption advisory for locally caught fish, based on nationwide average mercury levels in a variety of fish. Many states east of Kansas have mercury fish consumption advisories that include a mix of water-body specific and statewide advisories. EPA recommends that consumers limit consumption of any locally caught fish to not more than one 8-ounce meal per week. The advisory is designed to protect consumers in states lacking fish contaminant data. EPA further indicates that where there is better information, state advisories should take precedence. The EPA advisory rationale is found online at www.epa.gov/fishadvisories/advice/1-meal-per-week.pdf.

Since 2004, KDHE has been collecting additional fish tissue samples from both lakes and streams to evaluate mercury levels in Kansas fish. KDWP is now collecting fish samples from the 17 largest, most heavily-fished and harvested lakes every other year. KDWP is also collecting fish samples from many smaller public lakes. In addition to monitoring fish tissue quality in the large main-stem rivers, KDHE is also sampling smaller streams across the state. Details of monitoring efforts and protocols may be found in the Fish Tissue Contaminant Monitoring Program Quality Assurance Monitoring Plan, online at www.kdheks.gov/environment/qmp_2000/download/2007/FTCMP_QAMP.pdf

Currently, tissue samples are taken from bottom-feeding fish and from predatory fish, where available. Mercury tends to accumulate in predatory fish to a greater extent than in bottom-feeding fish. Earlier fish tissue contaminant monitoring efforts had focused on bottom-feeding fish, owing to the presence of pesticides and other organic chemicals (DDT, dieldrin, chlordane, PCBs, etc.). Average mercury concentrations in Kansas fishes remain lower than nationwide averages. KDHE protocol requires use of the average tissue mercury level when conducting water-body specific risk assessments.

Consumers of Kansas fish can safely eat at least two 8-ounce fish meals per week from any Kansas water body not under a specific KDHE/KDWP advisory. Data suggest higher levels of consumption are safe for most consumers. In time, data should be adequate for conducting individual risk assessments for our largest and/or most heavily fished and harvested lakes.

Women who are pregnant or nursing may wish to consult with their physicians about safe levels of fish consumption and mercury exposure. This sensitive group, and children under 12, should restrict their total mercury intake as related to both supermarket fish and locally caught species. Information on the FDA/EPA commercial fish advisory is available at www.epa.gov/fishadvisories/advice.

Fish consumption advisories assess cancer risk levels using EPA methods. Cancer risk assessment is a method to determine the added increase in cancer levels in a human 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 regarded as unacceptably high. Risk assessments for contaminants assessed as non-carcinogens (mercury, lead, cadmium) are based on 8-ounce serving size for adults and 4-ounce serving size for children nine to 18 years of age.

Testing for contaminants in fish and other aquatic life will continue. Information on the Kansas Fish Tissue Contaminant Monitoring Program can be found at www.kdheks.gov/befs/fish_tissue_monitoring.htm. Advisories are also posted on the KDWP website, kdwp.state.ks.us/news/Fishing/Are-My-Fish-Safe-To-Eat.