Toddlers Could Be Tested For Mercury
States seek grants to address threat posed by toxic metal found in fish
Bruce Henderson in the Charlotte Observer.
On The Waccamaw River – After more than a decade of measuring mercury
in fish, water and air, Carolinas officials will seek grants this week to
test a final frontier: people.
Thousands of people on the coastal plain, where mercury most
commonly takes a toxic form, would be tested if the Centers for Disease Control and Prevention approves the grants. Many in Piedmont counties east of
Charlotte would be tested, too.
Even without a CDC grant, South Carolina hopes to forge ahead with
plans to test 12,000 toddlers, who are at special risk.
In North Carolina, a state toxicologist estimates 7,400 children
born each year are already at risk from mercury. In its most toxic form, it can
cause neurological damage to developing fetuses and harm the way children
think, learn and problem-solve.
A naturally occurring metal, mercury also blows out of industrial
smokestacks, mostly coal-fired power plants and incinerators. Released
into the air, mercury falls back to earth in rain. A national study released
last month indicated average concentrations of mercury in rainfall in the
Carolinas were at least twice as high as the Environmental Protection
Agency says is safe in surface waters.
The chemistry of the Carolinas’ blackwater rivers on the coastal
plain transforms mercury into a highly toxic form. Called methylmercury, it
works its way up the food chain from tiny organisms to the largest fish. People
are most often exposed to it by eating contaminated fish.
Most previous estimates of mercury’s health impact in the Carolinas
have been projected from concentrations measured in fish and water.
Testing people is a direct approach.
“Blood doesn’t lie,” said Karen Brazzell of the S.C. Department of
Health and Environmental Control’s biomonitoring unit.
Each year the Carolinas update advisories on what fish species and
waterways to avoid. The growing list now covers the half of North Carolina
south and east of Interstate 85, and 53 rivers and lakes in South
Because of the potential damage to developing babies, pregnant women
are especially cautioned not to eat fish known to be high in mercury.
But some officials worry the warning isn’t reaching the people who
most need it.
Many of the coastal plain’s poor rely on fish for a substantial part
of their diet. They may also be less likely to read newspapers, brochures
or Web sites where mercury information is posted.
Neither state budgets money for public outreach. North Carolina
sends fact sheets to doctors, clinics and health departments, but hasn’t spent
the $42,000 it would cost to print and mail posters and brochures —
information women could take home and post on the refrigerator.
South Carolina mails 30,000 to 40,000 information booklets a year.
“We do the best we can within the scope of no resources,” said Tracy Shelley,
a state environmental toxicologist.
Mercury News Misses Many
The Waccamaw River flows between the two states, a tea-brown syrup
oozing downstream from Lake Waccamaw in southeastern North Carolina to
Winyah Bay at Georgetown, S.C.Tests of people who live along the N.C.
portion of the river, in 1993, found 10 times more mercury in frequent
fish eaters. Some concentrations were among the highest in the nation.
Despite fish-consumption advisories out for several years, mercury
is still news to some local people.
“I haven’t heard anything about that, and I’ve been here nearly two
years,” said Myra Ward, who owns a bait-and-tackle store near the
“I see a truck come here and test the water ever so often, but they
haven’t said anything to me about it.”
North Carolina advises limiting consumption of three freshwater
predators — largemouth bass, blackfish and chain pickerel. State
advisories also include the saltwater species shark, swordfish, tilefish and king
Michael Best, 40, who regularly fishes the Waccamaw, knows about
mercury — he believes he has seen it in largemouth bass and bream. It
looks like pockets of the silvery liquid in oral thermometers, Best said.
Biologists say mercury isn’t visible in fish. Best said he cleans
out the mystery substance and eats the fish. “It ain’t never bothered me yet,”
Interest in mercury is growing in Washington, Raleigh and Columbia.
North Carolina’s Clean Smokestacks Act, enacted last summer, is
expected to reduce mercury emissions by 55 percent by 2013 as power plants
install pollution controls for ozone and haze-forming chemicals.
The Bush administration says its Clear Skies Initiative would, by
2010, reduce mercury in Carolinas rainfall by up to 25 percent. N.C. power
plant emissions would drop 56 percent and S.C. emissions 64 percent by
The Natural Resources Defense Council — an advocacy group critical
of Bush’s proposal — estimates the Bush proposal would let power plants
release five times as much mercury for a decade longer than the Clean Air
Act now does.
Scientists, meanwhile, aren’t able to say how much of the
contamination in water and fish comes from industry.
“The big question is what concentration coming out of a smokestack
is going to equal what concentration in a bass that you’re going to pull out
of a lake and eat?” said Todd Crawford of the N.C. Division of Air Quality.
“There’s so much that happens between that smokestack and that fish that
it’s a daunting question.”
The state has measured mercury in rain at two spots in Eastern North
Carolina, Lake Waccamaw and Pettigrew state parks, since 1996 without
drawing a clear picture of whether more or less mercury is falling.
S.C. fish consumption advisories rose rapidly in the early l990s as
state officials expanded their tests of fish and waterways, said Butch
Younginer, aquatic biology manager for the S.C. Bureau of Water.
“In the last three years the numbers and intensity of mercury in
fish have pretty well leveled off,” he said.
The N.C. air-quality division is also studying the amount of mercury
in Charlotte’s air.
An Environmental Protection Agency study, based on computer
modeling, predicted in 1996 that Mecklenburg County would be in the top 5 percent of counties nationally. Air samples, to be collected through fall, will tell
whether the EPA estimate was accurate.
Even at high levels, Crawford said, it’s doubtful airborne
mercury — in a different form than methylmercury — would be harmful.
An ongoing study of fish, water and sediment in 13 sites across
Eastern North Carolina has found levels of methylmercury similar to those
in other parts of the Southeast, said Michelle Woolfolk of the N.C. Division
of Water Quality. Southeastern levels tend to be higher than in the rest of
Using analytical equipment that can detect mercury at levels 1/400th
that of previous methods, the study will let researchers use water samples
to estimate more accurately the levels of methylmercury in fish.
In September, the CDC plans to award $5 million in grants to states
that want to begin testing humans for environmental contaminants. Future
funding will allow some of the projects to last nearly five years.North
Carolina would use its grant to test for mercury in blood, urine, hair and
toenails in fish-eaters from 14 counties, ranging from Union, Cabarrus,
Stanly and Anson eastward to Brunswick and Columbus in the state’s
southeastern corner. One hundred people from each county would initially
be tested, but state officials say the number could eventually expand to as
many as 18,000 over 20 years.
Starting in March, South Carolina would test blood samples for
methylmercury from 1-year-olds in 23 counties. Children of that age are
already tested for lead.
The state has partnered with the Medical University of South
Carolina, which is studying the prevalence of autism and developmental disabilities
in coastal and Pee Dee counties. Researchers want to learn whether there is a
link to the prevalence of mercury, and whether developmental problems crop
up at certain doses.
Scientists are increasingly concerned about environmental
contaminants, said Dr. Jane Charles, a developmental pediatrician at MUSC
who studies autism and mental retardation.
“If you have a whole county full of children whose IQs are a few
points lower than you would normally expect, what kind of effect does that
have on the state?” she said.
Mercury on the Web
For fish-consumption advisories, visit the N.C. Department of Health
and Human Services: http://www.schs.state.nc.us/epi/fish/index.html or the
S.C. Department of Health and Environmental Control:
http://www.scdhec.net/eqc/ admin/html/fishadv.html For more on mercury,
see the EPA’s site: http://www.epa.gov/ mercury/index.html