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David Naftz, a geochemist, left, and Terry
Kenney, a hydrologist with the U.S. Geological Survey, collect water samples
from the Great Salt Lake earlier this month to check for mercury levels.
Tests have shown contamination about 25 times the level that prompted warnings
in the Everglades.
(Al Hartmann/The Salt Lake
Tribune)
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GREAT SALT LAKE - David Naftz and Terry Kenney are
searching the brackish water for clues about a potent poison.
Their white jumpsuits might make you mistake the two for hazmat responders
or astronauts. But they are scientists probing how toxic mercury is getting
into the lake and morphing into a dangerous neurotoxin.
For long stretches they ignore a glorious Indian summer day, taking samples,
jotting down observations. Kenney sniffs a jar of brine he has pumped from
the lake bottom.
"Bah!" he says, twisting his face away. "It's not healthy!"
You're bound to agree, no questions asked, if you've ever gulped a breath
of rancid Great Salt Lake air. But a serious, more troubling question has
emerged in recent months: Is mercury making Utah's environment truly sick?
Scientists and policymakers agree that it's too soon to answer
that question. They have too little data now - just a few hundred samples
of water, fish and waterfowl - to draw sensible conclusions. So, before they
ask for money or set priorities, they need to figure out what questions to
ask.
"We're learning," says W. Clay Perschon, who leads the Great Salt Lake Ecosystem
Project in the state Department of Natural Resources. "It's like with each
page of the book you are turning, you have learned more than you did two
pages ago."
His agency was one of three compelled to act after tests turned up
troubling levels of mercury in some Utah wildlife and fish. Like many Utah
regulators, Perschon believes the most pressing issue is protecting people
who might eat
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David Naftz, a geochemist, left, and Terry
Kenney, a hydrologist with the U.S. Geological Survey, collect water samples
from the Great Salt Lake earlier this month to check for mercury levels.
Tests have shown contamination about 25 times the level that prompted warnings
in the Everglades.
(Al Hartmann/The Salt Lake
Tribune)
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contaminated fish and birds.
Days before the duck season began earlier this month state officials warned
hunters not to eat two species of waterfowl because their flesh might contain
too much mercury. Although some states have grappled with mercury pollution
for decades, no others have such a warning. Some see it as a signal Utah
already has an extraordinary problem.
Two months earlier, the same officials urged anglers to limit fish eaten
from a stream on the eastern side of the state and a reservoir on the western
side. The advisories made Utah the 47th state in the nation to issue sport
fish consumption warnings because of mercury.
Mercury moves from place to place in the air and in rivers and streams. Erupting
volcanoes or burning coal can pump it into the skies. In the West, mercury
may also come from mining, including refining or "roasting" ores and runoff.
It becomes toxic when it changes into methyl mercury. In wildlife and humans,
methyl mercury settles in fat cells and builds up in the food chain. At high
levels, it can cause brain and nervous system damage. Its victims can become
nauseous, suffer muscle weakness and experience memory loss.
Although babies are thought to be most susceptible, new evidence suggests
mercury also can complicate heart conditions, infertility and autoimmune disease
in adults.
Generally, people don't breathe too much mercury. They eat it, usually in
fish. The U.S. Environmental Protection Agency and the U.S. Food and Drug
Administration have issued a joint warning about mercury aimed at pregnant
women, childbearing-age women and children
that focuses on predatory species, such as swordfish and tuna.
That standard helped guide Perschon's agency, together with the state departments
of Health and Environmental Quality, to warn the public about eating northern
shovelers or common goldeneye ducks, and to limit the amount of Brown trout
from Moab's Mill Creek and largemouth bass from Gunlock Reservoir near St.
George.
Perschon's office will sample more waterfowl in coming months in hopes of
getting a clearer picture of how widespread mercury contamination is. They
also hope to learn whether migrating birds bring mercury with them on their
international routes or shed it when they leave.
Just a hunch: Naftz, a biochemist, got a hunch a couple of years ago while
studying the lake for the U.S. Geological Survey. He had been taking measures
of the Great Salt Lake's deep brine layer, the salty pools that form in the
lake's underwater basins, when he realized it was ideal for the chemistry
that converts mercury to its toxic form.
Testing his hypothesis would require special techniques and gear. That's
why Naftz and Kenney wear the special suits when they test: they need to
protect the mercury at miniscule concentrations, parts per trillion.
They use Teflon bottles - at a pricey $100 apiece - to ship their samples
to the U.S. Geological Survey mercury lab in Wisconsin. They wear the white
"spacesuits" and layers of gloves so nothing on them contaminates the samples.
"Even a speck of dust could be a problem," says Naftz.
When they did the first tests for mercury, the results were shocking.
Not only was the contamination high - about 25 times the level that prompted
warnings in Florida's Everglades - but it had greater concentrations of toxic
methyl mercury than U.S. Geological Survey had seen nationwide.
Normally, the proportion of methyl mercury to total mercury was about 5 percent.
The Great Salt Lake samples showed concentrations, in a few cases, of more
than 50 percent.
A neurotoxin factory is what Naftz had discovered.
Meanwhile, the U.S. Fish and Wildlife Service examined eared grebes, migrating
birds that feed from May to December on Great Salt Lake brine shrimp.
David Krabbenhoft, who heads the USGS lab in Wisconsin, said the high levels
were surprising even to him, a scientist known as "Mr. Mercury" who's been
studying it for nearly two decades.
He was stunned again this month to hear about the state's data on game birds.
"I never would have dreamed that [mercury levels in] ducks could get that
high," he says.
The findings underscore how little mercury is understood in Utah's unusual
environment, adds Krabbenhoft. "We need to do more homework."
Where it's from: Cheryl Heying of the Utah Division of Air Quality has been
on a crash course to understand how mercury gets here by air. China may send
it on air currents, one scientist suggests.
Another points to natural dispersal from the mercury-rich desert dirt. Still
others blame the roasters at
Nevada gold
mines that released more than 5,000 pounds of mercury into the air and landed
two mines sites on the nation's top-ten mercury emitters in 2003. "We have
to know what's coming out of the stacks," says Heying, who serves on the
state's 15-member Mercury Work Group.
She's not even sure if computer-generated models of pollution's flow that
were developed elsewhere will work here, or how they might be adapted. Meanwhile,
casual testing doesn't seem economical, given that monitors cost about $100,000
each.
It's just too soon to suggest what mercury-air studies are needed, she says.
"It's very complex. It's very controversial."
More questions: "There are a heck of a lot more questions that we would like
to have answers to," agrees Nathan Darnall, an ecologist with the U.S. Fish
and Wildlife Service who has more in-depth studies underway.
It's more than scientific curiosity, he explains.
"In a lot of ways, our wildlife are like canaries in the mine. What affects
them is going to affect us."
So far, USGS tests have cost about $5,000. The state's fish-tissue
analysis has run up a $2,800 tab, and a new mercury-analyzing machine for
the state Health Department lab was about $50,000.
And, while more tests are in the works, it remains unclear whether it will
cost 10 or 20 times as much - or more - to really understand how bad the
problem is let alone what, if anything, should be done to protect people
and the environment.
Environmentalist Justin Hayes
agrees. His group, the
Idaho Conservation League, traced airborne mercury to the Nevada gold roasters.
He hopes that Congress will make a special appropriation for the task under
pressure by Sen. Orrin Hatch, R-Utah, Sen. Harry Reid, D-Nevada and Sen.
Larry Craig, R-Idaho.
"They are just going to have to put the resources into this," he says. "It's
a big thing to get our arms around, but it has to be done for the sake of
the health of our children and the health of our environment. I just don't
think they can ignore it."
Meanwhile, Naftz and Kenney motor across the lake once a year to take more
samples, to learn more. They take hundreds of painstaking measurements each
time and help build the state's knowledge base.
"Logistically," Naftz says, "it's . . . "
"A nightmare," offers Kenny.
fahys@sltrib.com |
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