News Coverage
Kids most susceptible to mercury
Published September 14, 2002
Mercury is highly toxic and can cause neurological problems ranging from declining IQ scores to convulsions or an inability to walk. Extreme exposures are fatal.
Children and fetuses are especially susceptible. Scientists say mercury contamination in walleye and other fish at the top of the food chain can be thousands of times greater than the contamination in water. So mercury is of particular concern in popular fishing waters, such as Lake Roosevelt.
Mercury is the most common cause of government warnings to limit fish consumption. Thirty-nine states have issued such advisories for at least one water body, according to the Environmental Protection Agency. Nine states warn about high mercury levels in every lake and river within their boundaries.
At Lake Roosevelt, the Washington Department of Health issued a fish-consumption warning in 1990, after studies showed elevated levels of mercury, cadmium, dioxins and PCBs. The agency initially warned that children should not eat whitefish.
A year later, after more studies, the department rescinded that order, saying people were safe eating up to 20 helpings of fish a month, as long as they removed the skin and as much fat as possible.
Meanwhile, British Columbia health officials warned that no one should eat more than two meals a week of large walleye taken downstream of the Cominco smelter in Trail. They issued a similar advisory for whitefish in 1992.
The Canadians lifted both advisories in 1996, after tests showed reduced fish contamination. Washington tests during the mid-1990s showed a dramatic decrease in mercury, dioxins and furans in trout and walleye.
However, the state Department of Health still recommends a limited diet of fish from Lake Roosevelt. The agency has recently launched a statewide effort to reduce mercury exposure, primarily by reducing the amount of mercury released into the environment and restricting the disposal of consumer products such as barometers, thermometers and thermostats.