Persistent bioaccumulative toxins of greatest concern are PCBs (a man-made chemical), PBDEs (a new generation of flame retardant) and dioxins/furans. Lead, arsenic, cadmium, and zinc are heavy metals released from mining operations and are also of concern.
When eating fish from the Spokane River, be aware of Washington State Department of Health (DOH) recommended limits. Eating fish from the stretch of river between the Idaho border and Nine Mile Dam may impact human health. DOH also recommends special precautions when cooking and cleaning fish to reduce contaminants (see Fish Consumption).
Sediments at certain recreational beaches from the Idaho border to Upriver Dam are also of concern. The Washington Department of Ecology and other agencies are actively cleaning up and restoring contaminated beaches identified as areas of potential risk (see Cleanup and Restoration).
Reducing or eliminating toxic chemicals in the river is a very difficult challenge because:
- Pathways to the river vary widely. While most toxic substances are directly deposited in the river, others migrate to the river via tributaries, runoff, stormwater drains, and air particulates
over a period of days or years.
- Sources are both near and far away. It is fairly easy to understand the effects of an industrial plant located on the river bank. It is a little harder to understand the effects of a mining operation 100 miles or so upstream. Still harder to understand are toxic chemicals from household, industrial, or farming products that often find their way into the river via ground water, stormwater drains, or wastewater treatment facilities. Even more difficult to grasp are the possible effects of a coal-fired power plant or incinerators located hundreds of miles away. All, however, can contribute to contaminants in the Spokane River.
- Regulatory practices often come after a problem becomes known. For instance, PCBs were only banned after years of being released into the environment. PBDEs were banned in
Washington State in 2007. Recently, EPA adopted a reference dose, which is the maximum acceptable oral dose of a toxic substance, for PBDEs. For future advisories, this will help determine safe levels of fish consumption.
In addition, some chemicals are regulated but become too concentrated in certain locations. This may happen when persistent chemicals deposited in an area build up over time. Some deposits build up when persistent chemicals travel to a location via air and water.
Addressing these challenges requires a collaborative effort across many public agencies, private industries, environmental groups, citizens and others with expertise and commitment to meeting the needs of the Spokane River.