PCBs: a Toxic Legacy and Ongoing Problem

According to the U.S. Environmental Protection Agency (EPA), PCBs are among the most widespread contaminants in the Columbia River. They are persistent, meaning they do not readily break down in the environment. On top of that, PCBs accumulate in the food chain, impacting human and environmental health. Although the United States banned the manufacture of PCBs 1979, with some exceptions, contamination throughout the Columbia River Basin remains today. 

What are PCBs?

PCBs are part of a family of human-made chemicals known as chlorinated hydrocarbons. In the United States, over 1.5 billion pounds of PCBs were manufactured from 1929 to 1979, when production and import of PCBs were mostly banned based on evidence of their toxicity. Valued for their properties of chemical stability, insulation, and non-flammability, PCBs were used in many electrical, industrial, and commercial applications. Today, PCBs can still be found in products and materials that were made prior to 1979, and the ban continues to permit some inadvertent PCB production. PCBs persist in the environment and can be found in high levels in the Columbia River, particularly near Superfund sites like the area around the Bonneville Dam.

What are the health risks?

PCBs are associated with a variety of cancerous and non-cancerous health effects in animals  including impacts to the:

• immune system,
• reproductive system, 
• nervous system, and
• endocrine system.

The EPA designated PCBs as probable human carcinogens and research shows a variety of adverse health effects. Diet is a major pathway of PCB exposure in people, and eating contaminated fish is one of the primary dietary sources of these chemicals.

How do PCBs enter the Columbia River?

PCBs enter the Columbia River from illegal dumping, improper disposal of PCB-laden materials, and leaks or spills of PCB-containing fluids. Additionally, because the manufacturing ban is incomplete and still permits low-level PCB production, many consumer products — especially those with pigments or dyes — continue to contain PCBs, leading to ongoing environmental releases.

Additionally, there are many contaminated waste sites contributing to the significant PCB pollution in the Columbia River. At the Bonneville Dam, for example, the U.S. Army Corps of Engineers disposed of toxic waste into the Columbia River for decades. These materials continue to leach contaminants into the river causing fish that reside in the area year-round to have some of the highest levels of PCBs in the country. Today at Bonneville Dam, fish advisories suggest avoiding any consumption of resident fish due to PCB contamination.

Are PCBs in Columbia River salmon?

PCBs are fat-soluble and over time they biomagnify up the food chain, occurring at high levels in top predators, including humans. On the Columbia, fish like salmon and steelhead (which live part of their lives in the ocean) typically contain lower levels of contamination than resident fish like sturgeon and bass (which live their entire lives in the Columbia River). This explains why state-issued fish consumption advisories — often driven by PCBs — are more commonly issued for resident fish. However, when it comes to human exposure, how much fish you eat matters. Recent testing by ProPublica and OPB found Columbia River salmon with PCBs levels that pose an unacceptable health risk under EPA guidelines when consumed at rates typical of Tribal people, meaning Tribal communities face disproportionate risks through consuming one of their most important foods.

Are there ways to reduce exposure to PCBs when eating fish?

Yes. PCBs build up in the fat of fish and can be reduced by:

•  removing the skin, fat, and internal organs before cooking; and 
• grilling, baking, or broiling fish so that the fat drips off while cooking. 

Visit the Oregon Health Authority’s website for more details on fish cleaning and cooking guidelines.

Who is researching PCBs on the Columbia?

Some of the research looking at PCBs on the Columbia River includes:

• An Oregon State University project using passive sampling devices to monitor bioavailable toxic organic compounds and study water quality on the lower 170 miles of the Columbia River to better understand toxic pollution and its impacts.

• The Confederated Tribes and Bands of the Yakama Nation and partners are working on a multi-year project to develop a long-term fish tissue and water quality monitoring program to track the status and trends of contaminants in fish, water, sediments and invertebrates in the Columbia River from the Canadian Border to Bonneville Dam.

• In an effort to update the current status of contamination in the Lower Columbia River, a USGS and Lower Columbia Estuary Partnership project uses passive samplers to monitor previously studied sites for pollutants like PAHs, PCBs, PBDEs as well as PFAS  (per- and polyfluoroalkyl substances) and cyanotoxins.

To learn more about other studies on pollution in the Columbia River, check out the following resources:

• USGS ConHab study
• EPA and Columbia River Inter-Tribal Fish Commission Fish Contaminant Survey
• EPA Mid-Columbia Toxics Assessment
• EPA State of the River Report

How can we reduce the amount of PCBs in the Columbia River?

PCB contamination on the Columbia River is a lasting and widespread problem. To protect and restore the Columbia River, a variety of actions are underway and needed to reduce PCBs. For a deep dive into strategies to reduce PCBs, check out the Washington Dept. of Ecology’s Draft Chemical Action Plan for PCBs. Other examples of strategies to reduce PCBs in the Columbia include:

• designate and clean up toxic waste sites that contain PCBs;
• reduce ongoing wastewater and stormwater pollution that contains PCBs;
• promote the use of manufacturing practices that do not inadvertently cause the production of PCBs;
• fund clean water programs;
• support monitoring and research to better understand the sources, pathways, and impacts of toxic pollution.

This publication was developed under Assistance Agreement No. 02J83901-0 awarded by the U.S. Environmental Protection Agency. It has not been formally reviewed by EPA. The views expressed in this document are solely those of Oregon State University and EPA does not endorse any products or commercial services mentioned in this publication.