Columbia River

Fish Contaminant Survey

About the survey

The Columbia River Basin Fish Contaminant Survey is a technical report that assesses the amount of chemcial pollution in certain species of fish, and the potential health risks from eating fish those fish. The study is based on fish samples collected between 1996 and 1998 from tribal fishing waters in Washington, Oregon and Idaho.

Who conducted it?

EPA funded the study which was coordinated by the four member tribes of the Columbia River Inter-Tribal Fish Commission (CRITFC): Exit

  • Confederated Tribes of the Warm Springs Reservation of Oregon
  • Confederated Tribes and Bands of the Yakama Nation
  • Confederated Tribes of the Umatilla Indian Reservation
  • Nez Perce Tribe

Five things we learned

  1. Tribal members were eating six to eleven times more fish than EPA's estimated national average (at that time) of 6.5 grams per day.
  2. The study showed the presence of 92 contaminants in fish consumed by tribal members, including polychlorinated biphenyls (PCBs), dioxins, furans, arsenic, dieldrin, mercury, and DDE - a breakdown product of DDT.
  3. Salmon, steelhead trout, smelt and rainbow trout had the lowest levels of chemical contaminants, so the risks from consuming these fish were lower than the risks from consuming species which had higher levels of contamination, such as white sturgeon, largescale sucker, and mountain whitefish.
  4. Estimated cancer risks were highest for the more contaminated resident species (e.g., mountain whitefish, white sturgeon, and large-scale sucker) and increased as people ate more fish, more often, and over a longer period of time. Adults in CRITFC's member tribes who eat fish frequently (48 meals per month) over a period of 70 years may have cancer risks that are up to 50 times higher than those in the general public who consume fish about once a month.
  5. The chemical concentrations in fish were generally lower than levels reported in the literature from the early 1970's and similar to levels reported in the late 1980's.

Why is it important?

  • The Oregon Department of Environmental Quality used data from the survey to establish new standards that help ensure that fish in Oregon's waters are safe to eat. Oregon's new standards are based on an average fish consumption rate of 175 grams per day (about 6.2 ounces, or 23 8-ounce fish or shellfish meals per month) - making them the most protective of any state in the U.S. Learn more about Oregon's water quality standards Exit
  • EPA and others are also using the data to help focus our toxics reduction efforts in the Columbia River on particular chemicals such as PCBs, DDE, dioxins, furans, mercury, arsenic. Read EPA's Columbia River Toxics Reduction Action Plan

Read the full report

Questions?