News Coverage
Study Finds N.C. Mercury Levels Above Safe Levels
Published May 23, 2004
North Carolina allows potentially unsafe levels of mercury in rivers and lakes, according to a new study of the toxic metal.
The draft report by the state Division of Water Quality uses a new method that detects mercury at minute levels, analyzed water, sediment and fish in 13 locations in eastern North Carolina.
"It provides us with answers to questions we've had for years," said Luanne Williams, a toxicologist at the state Department of Health and Human Services.
The study found that mercury is dangerous at much lower levels than state water-quality rules recognize.
Those standards are meant to limit pollutants to levels that are safe for aquatic life and people. They also determine the amounts that can be dumped into rivers and lakes by discharge sources, such as waste-treatment plants.
State rules allow no more than 12 nanograms of mercury per liter. But to protect people who eat big largemouth bass from Lake Waccamaw in southeastern North Carolina, the study showed, it should be as low as 0.9 nanograms per liter.
"We agree that a lower number is probably going to be recommended," said Boyd Devane, who heads the planning branch of the state water-quality section.
A three-year review of the mercury standard, which went into effect in the 1980s, begins this year. The review will focus not only on a new numeric standard, Devane said, but also on updated science and health concerns.
North Carolina has fish consumption advisories for bowfin, largemouth bass and chain pickerel caught south and east of Interstate 85. "We need to lower our water-quality standard to a level that would keep fish at healthy levels," Williams said. "The second thing we need to do is better define where the mercury that's going into vulnerable areas is coming from, and what control measures can be placed on them."