State health officials are telling Alaskans they can eat more locally caught fish than federal health agencies advise. They're taking a stand on the issue in a prominent national forum this week with an article in the March issue of The American Journal of Public Health.
A key concern in the federal advisories is mercury, a toxic metal found in fish and which can be passed along to people who eat them. Just how much fish to eat is particularly important in a state where some residents eat hundreds of pounds of fish, mainly salmon, every year.
In 2004, the U.S. Environmental Protection Agency and the Food and Drug Administration issued a joint advisory recommending that women of childbearing years and young children eat only 12 ounces per week -- two meals -- of fish low in mercury to limit their exposure to the toxin.
State public health officials call these national advisories overly conservative, restrictive and not applicable to fish caught in Alaska waters. They point to studies showing low concentrations of mercury in many of Alaska's fish. They're sticking by the advice they've issued many times in recent years: All Alaskans -- even pregnant women and children -- can eat an unrestricted amount of fish caught in local waters.
One of the article's authors, environmental toxicologist Scott Arnold, said he's concerned that people who depend on subsistence foods in rural parts of the state will follow the national agencies' limitations. The Alaska Native Epidemiology Center recently surveyed hundreds of Alaskans in 13 villages throughout the state. The villagers, many of them Alaska Natives, each ate from 30 pounds of fish per year to well over 200 pounds in western Alaska, said Carol Ballew, the center's director.
Dr. Jim Berner, who has studied mercury levels in Alaska Native women and their babies, supported the article's message of unlimited fish consumption in Alaska. The fish these women are eating are generally low in mercury and high in nutrients that support fetal development, he said. Because of that, he'd recommend eating more, not less, fish from Alaska waters.
BENEFITS AND RISKS
With leading health organizations giving different opinions, Alaskans are put in the position of choosing between them.
"I would hope that EPA and state of Alaska officials share the same concern of not wanting people to be so confused that they throw all advice to the wind," said Denise Keehner, director of standards and health protection with the EPA's water division. Doing so, she said, might lead to two things: not eating any fish or eating too much fish from non-Alaska waters that have high levels of mercury.
As they stand now, the federal guidelines overemphasize risks and ignore the health benefits of eating fish, according to the article, co-authored by Dr. Tracey Lynn, Lori Verbrugge and Dr. John Middaugh. They note that eating fish is linked to the prevention of certain cancers, cardiovascular disease and diabetes as well as improving nutrition in mothers and boosting a baby's development.
The national advice also ignores the ability to measure exposure to contaminants here, something state health officials are doing through studying both fish and people in Alaska, the article said.
Fishing is a large part of Alaska culture. It's also a less expensive source of food for people in rural Alaska who face high grocery prices, Arnold said. "It's so much cheaper for someone to go down to the river and catch a fish than it is to eat a steak out of the (Alaska Commercial) store."
The national fish advisories carry adverse consequences because decreasing fish consumption means substituting foods that are less healthy, the article's authors argue.
"Because of the current epidemic of nutritionally linked disease, such as obesity, diabetes and cardiovascular disease, general recommendations for limiting fish consumption are ill-conceived and potentially dangerous."
"Among Alaska Natives who rely heavily on these foods for their nutritional, spiritual and cultural health, the results can be disastrous," the article asserts.
MEASURING MERCURY
Mercury occurs naturally and is emitted by Earth's crust. It also comes from man-made sources, including coal burning and other industrial emissions. Mercury comes in different forms, and bacteria can convert the metal into methylmercury, which accumulates in small fish and organisms. Larger fish eat these smaller fish, sending methylmercury up the food chain. That means larger, older halibut could contain more mercury than smaller salmon, Arnold said.
Determining what is an acceptable amount of methylmercury is confusing because several government agencies use different guidelines. The EPA, the Agency for Toxic Substances and Disease Registry and the World Health Organization, for example, each have standards for mercury exposure. These levels differ because they're based on the agencies' analysis of different studies, Arnold said.
Keehner said the EPA's concern with methylmercury stems from its effect on a developing fetus. Too much mercury exposure can affect a baby's neurological system, potentially damaging his or her cognitive abilities, she said.
Alaska officials have tried to justify their recommendation for unlimited fish consumption by monitoring mercury levels in fish and people.
The state Department of Environmental Conservation has studied levels of PCBs and metals in hundreds of fish collected from major Alaska water bodies, including rivers and oceans, during 2001 and 2002, said Bob Gerlach, the state veterinarian managing the study. In that sample, 245 of the fish were salmon, which had the lowest average methylmercury levels of all fish -- .027 parts per million. The species with the highest concentrations of methylmercury were halibut, with an average of .217 parts per million, Gerlach said. The FDA's limit for human consumption in commercially sold fish is 1 part per million.
Between June 2002 and December 2004, the state Division of Public Health collected almost 250 hair samples from pregnant women and women of childbearing age. An analysis showed that the median level of mercury in the pregnant women's hair was .47 milligrams per kilogram; the median for nonpregnant women was .63. Both medians were far below 14 milligrams per kilogram, the World Health Organization's level at which there was no observed health effect from exposure, the journal article showed. The EPA and other agencies have lower standards, but Arnold said state health officials don't use them as a comparison because they are too conservative.
SALMON EATERS HEALTHIER
Dr. Jim Berner, director of community health for the Alaska Native Tribal Health Consortium, has coordinated another study of Alaska Native women and their babies in North Slope and Yukon-Kuskokwim Delta villages. In the late 1990s and early 2000s, Berner collected blood or urine samples from more than 200 pregnant women and dozens of babies and studied exposure to nutrients, mercury and PCBs. Berner found higher average blood levels of mercury in Alaska Native women than in U.S. women of all races, likely because the Alaska Native women ate more fish, he said.
Even so, Berner said, Alaska's levels were far below the lowest level at which you'd see health effects in the most sensitive person. The Yukon-Kuskokwim women in Berner's study also had low rates of delivering premature babies, low rates of diabetes compared to rates in other parts of the state and high levels of essential omega-3 fatty acids that are found in fish. These fatty acids promote fetal brain growth and eye development, Berner said.
Health officials and researchers working on Alaska's fish, hair and blood studies acknowledge limitations in their work, including small sample sizes. All of these studies are ongoing, however, and are expanding to examine more fish or people.
Keehner said last week that the FDA and EPA aren't permanently committed to the advice they issued in 2004 and are willing to hear about new information collected in Alaska. She said, however, that she needed more information than was provided in the journal article to decipher whether the studies done in Alaska were scientifically sound.
"I'd like to see the data, and I'd like to work with Alaska," she said.
Reporter Ann Potempa can be reached at 257-4581 or apotempa@adn.com.
Read an abstract of the study "Human Biomonitoring to Optimize Fish Consumption Advice: Reducing Uncertainty When Evaluating Benefits and Risks" by Scott M. Arnold et al. The full report is available for a fee.
"What You Need to Know About Mercury in Fish and Shellfish," advice from the Environmental Protection Agency
Information from the state on mercury and fish consumption
