Mercury Problems May Be More Serious Than Experts Thought (Seafood Alert)

Doctors and scientists say mercury exposure appears to afflict two groups in America -- well-educated people who can afford to buy the most expensive fish, and recreational anglers and poor "meat" fishermen who eat large marine fish regularly.

Some strong patterns appear to be emerging from new data gathered by sources including the New Jersey Department of Health, a clinic affiliated with Harvard University and doctors in San Francisco, Wisconsin and Canada.

The evidence suggests that high mercury levels in people, such as those found during hair tests conducted by the Mobile Register, may be much more common than doctors, scientists and government health experts have believed, especially in certain segments of the population.

The new data also shows that the country's main source of information about mercury levels in people -- a Centers for Disease Control health survey -- does not capture the widespread nature of the most severe levels of contamination.

CDC officials said their survey is designed to produce an average level for the entire nation, and cannot show the exposure levels for the most contaminated 5 percent of Americans, or 14 million people, because the agency has too few samples for such calculations.

"This is a disease of the wealthy. It's affecting the fine wine and fine fish crowd," said Dr. Jane Hightower, who has tested more than 100 patients at her San Francisco practice. "It's hitting the people who are following the prevailing health advice to eat a lot of fish and can afford to buy the good stuff."

Hightower said she started testing patients for mercury while searching for an explanation for symptoms she discovered in her patients, such as fatigue, hair loss, memory loss, muscle aches and difficulty concentrating. In a paper posted last year on the San Francisco Medical Society Web site, Hightower reported that 62 of 123 patients, all of whom ate a lot of fish, had mercury levels higher than the Environmental Protection Agency's safe level for mercury in the body.

Her results appear to mirror results obtained last year from Mobile Register-sponsored mercury testing of 70 Gulf Coast residents who said they ate seafood at least once a week. Hair samples tested by the Register indicated that a number of local seafood consumers had mercury levels five to 10 times higher than the EPA's safe level.

Twenty of the people Hightower tested had mercury levels at least four times higher than the EPA safe level. A handful of her patients tested more than 10 times higher than the safe level.

Similarly high mercury levels in affluent Americans have recently been documented around the country: A pair of lawyers in Wisconsin tested by that state's health department, and a number of Bostonians tested at a clinic affiliated with Harvard, had mercury levels 10 or more times above the safe level.

Hightower said she was shocked to find high mercury levels in her patients, some of whom are physicians, especially in light of new studies that appear to show a strong correlation between elevated mercury levels and increased risk of atherosclerosis, or hardening of the arteries. She said doctors are being caught off guard when it comes to mercury exposure from fish because the government has downplayed the risks.

Part of the reason that doctors find themselves surprised may be that the government has little data covering mercury in people and has been measuring mercury levels in the general population only since 1999. The main tool for examining mercury exposure in America is "less than ideal" and "not designed to capture the people with the highest mercury levels" or "account for mercury exposure in places like coastal towns," according to CDC officials recently interviewed by the Register.

Much was made of the CDC's health survey last month during a U.S. Food and Drug Administration meeting in suburban Washington to discuss the dangers of mercury in the nation's seafood supply. The survey, called the National Health and Nutrition Examination Survey (NHANES), showed that 8 percent of American women have mercury levels above what the EPA considers safe. Elevated mercury levels are believed to be a cause of birth defects.

At the meeting, speakers from the seafood industry and the FDA used the study to support their contention that mercury contamination is not much of an issue in this country, affecting less than 10 percent of the population.

Mike Bolger, one of the key players in the FDA's mercury policy, used the CDC data to support a claim that even the most exposed people in America "still have a margin of safety" from dangerous levels of mercury. Bolger was referring to the fact that the EPA's "safe level" of 1 part per million of mercury in the body was set 10 times lower than the "benchmark" dose -- the level at which effects on humans become apparent.

But EPA officials believe mercury may begin to affect people at levels well below the benchmark level. And some of the people tested by Hightower, the state of Wisconsin, the Cambridge Health Alliance and the Register were found to have mercury levels that exceeded the benchmark dose, eradicating any "margin of safety."

At the July meeting, the EPA and consumer groups used the CDC data -- showing that about 8 percent of the population was above the safe level -- as evidence that tens of millions of American women and children are exposed to what they termed dangerous amounts of mercury.

"The truth, as usual, is probably somewhere in between," said Alan Stern, a member of the National Academy of Sciences and a mercury specialist with the state of New Jersey. "But remember, it's not at all inconsequential that around 10 percent of the population are over the safe dose for mercury. That is a red flag.

"If something like 1 to 3 percent of the population is at a level of mercury exposure where we might expect there to be a significant risk of recognizable effects, that is not a small number."

Although it has become the primary source for information about mercury exposure in Americans, the CDC's NHANES survey misses the segment of the population it is most important to reach, namely those with the highest mercury levels, according to officials with the CDC, the EPA and many state health officials.

Even the FDA officials who use the data to support their position that mercury is not a major health problem say that new and better data is needed.

A CDC Web site acknowledges that "NHANES cannot provide estimates of mercury exposure in certain highly exposed groups" and explains that the survey's sample size was too small.

The NHANES study was originally designed to cover a broad range of health concerns other than mercury. Statistics about the percentage of Americans suffering from high cholesterol, for example, usually come from the NHANES survey. The survey, which has been conducted for 40 years and consists of interviews and more than 100 different kinds of blood tests, is well respected by the medical community. Some doctors call it "a kind of gold standard of national health data," particularly when it comes to looking at issues such as obesity.

But a Register analysis of NHANES revealed significant gaps in the mercury data. Mercury tests were conducted on only about 20 percent of those surveyed by the CDC, greatly reducing the sample size. And the agency collected far fewer samples in coastal areas, where 53 percent of Americans live and where scientists expect mercury problems may be most pervasive because of increased access to large marine fish.

CDC officials acknowledged limitations in the mercury monitoring portion of NHANES, and said it was tacked on to the survey three years ago as officials realized that mercury contamination from fish might be a growing national health concern.

"We would be the first to agree that if you're looking at a mercury survey, NHANES may not be the best tool," said Bill Crews, one of the top CDC officials involved with the survey. "But the fact that everyone is mud wrestling over the data may indicate it's the best we've got right now."

Each year, the CDC tests about 5,000 people from 13 U.S. counties. The agency says that three years' worth of data, when combined, represents about 15,000 people and provides a kind of picture of America's general health.

But for the mercury portion of NHANES, only 2,414 people were surveyed over two years, in 1999 and 2000. No men, older women or children over age 5 were included -- only women between 16 and 49 and children ages 1 to 5 were tested because the fetus and young children are thought to be especially sensitive to mercury exposure.

Scientists note that the younger children are in fact far less likely than adults to consume enough fish to build up dangerous levels of mercury, further limiting the usefulness of the data.

With new evidence emerging linking mercury exposure to hardening of the arteries and possibly other problems in adults, Kate Mahaffey, author of the EPA's Mercury Report to Congress, said it has become apparent that more data on a broader spectrum of the population would be useful. She also said a survey looking more directly at the groups thought to be most at risk, such as people living near the coast, is needed.

The CDC's Crews said his agency has been advocating a more focused survey he called "Community Hanes," that would be designed to examine much narrower sections of the population. Crews said it would be the perfect vehicle for probing mercury levels in at-risk groups. The problem is, the CDC can't get the necessary funding.

NHANES may have further underestimated mercury exposure in America through the selection of testing locations.

The CDC does not release the locations of the counties it selects for its annual testing, but by combing through local news accounts and contacting other official sources, the Register learned where much of the NHANES data was collected.

In 1999 and 2000, the only years for which mercury data has been released, relatively few coastal counties were tested by CDC, although Census numbers show that more than half of Americans live in coastal counties. Mercury experts believe mercury levels may be significantly higher in such coastal communities.

"If you had more communities in coastal areas where fish consumption was more prevalent, we might see more people with these high levels," said EPA's Mahaffey. "I think one of the important things to be done is to get more data from regions where we expect fish consumption to be higher."

During 1999 and 2000, the agency tested 27 counties. Excluding four highly urbanized counties in southern California, where minority populations such as blacks and Hispanics were the focus of testing, only five of the remaining 22 counties were coastal. One of those five was an extremely remote county on the Texas coast.

Crews pointed out that even when the agency samples a coastal county, such as the Tampa Bay area, it is entirely possible that none of the about 500 people sampled by CDC consumed a lot of fish.

"NHANES was designed to provide a national picture for a variety of things," Crews said. "It wasn't designed to measure mercury in certain groups. If you're trying to look at mercury levels in a micro-population, such as coastal towns or seafood eaters, it simply wasn't designed for that."

Whether the 53 percent of the population who live in coastal counties represents a micro-population or the majority of Americans, many health experts agree that NHANES failed to identify the portion of the population with the highest mercury levels.

"I agree that NHANES is not a very good vehicle for finding out mercury levels for the high-end fish consumers, but where do you look?" asked New Jersey's Stern, who works with that state's Division of Environmental Health. "The problem is, how do you get to these people? If you want to find people with high lead levels, you look at inner-city kids. There is no analogous place to look for people who eat fish. They're very rich. They're very poor. They live all over the place."

Hightower agreed that even with more testing in coastal communities, the agency would have a hard time finding the people most at risk for mercury.

"This is a coastal problem afflicting the affluent. These folks aren't waiting around for CDC to fill out forms and go through getting tested," Hightower said. "This whole thing has been under our noses for years. We just didn't see it."

Mahaffey said it is well recognized that NHANES cannot capture the 5 percent of the population with the highest exposures, due to its limited sample size. For that reason, she said it's significant that the NHANES revealed as much mercury exposure as it did.

"I was actually a little surprised to find the prevalence of levels over the (safe) dose," Mahaffey said. "To me it says the occurrence of these elevated mercury levels is a lot more frequent than I would have anticipated."

Dr. Sanford Miller, a retired senior FDA official who used to be in charge of the agency's official mercury advice, headed the independent panel making recommendations to the agency at last month's meeting. Miller said his panel concluded that FDA needs better data when it comes to measuring mercury in the population.

"What necessarily needs to be done is a survey on the populations that have access to large amounts of these fish with higher mercury levels," said Miller.

"When I first began looking into the problem facing my patients, another physician commented that, 'No one will care about a bunch of rich people eating expensive fish and getting sick on it,'" said Hightower.

"Then, as I began having more physician patients and colleagues testing high, tuna was mysteriously removed from the doctors dining room menu," she said, speaking of tuna steaks, which have fairly high average mercury levels. "The nutritionists now give us the smaller fish. My colleagues now commonly ask me, 'So what are those fish that are high in mercury?'"

She makes a case that restaurants and consumers are more inclined to purchase fish that can be served or sold as boneless steaks. Those steaks usually come from the larger fish that scientists say tend to have higher mercury levels, which quickly build up in the people who eat them.

In Wisconsin, the state Division of Health documented a husband and wife, both lawyers, with mercury levels 10 and 12 times higher than the EPA's safe level. The husband reported sleep disturbances and difficulty concentrating. The family's mercury intake was traced to two meals per week of imported sea bass -- also known as Chilean sea bass or Patagonian toothfish -- purchased at a local market. The state health officials reported that six months after the family members quit eating the sea bass, their mercury levels had returned to normal.

The results of mercury testing sponsored by the Mobile Register last year also appear to support Hightower's contention. All but 14 of 65 Gulf Coast residents who reported eating fish at least once a week had mercury levels above the EPA's safe level.

Eleven of those tested by the Register had mercury levels from five to 11 times the EPA safe amount. These highest levels were recorded among well-educated people, including doctors, scientists and business people who said they ate steaks from large fish such as amberjack, grouper and tuna. One woman who ate a single tuna steak sandwich per week and no other seafood was found to have a mercury concentration more than four times the EPA's safe level.

Another recent study examining health records from the Cambridge Health Alliance, a clinic affiliated with Harvard Medical School, concluded that regular consumption of commercially available fish can lead to high mercury levels in the human body. The study examined the records of 71 patients who had undergone mercury testing for hair, blood or urine since 1986.

"For 31 patients with adequate dietary history, there was a significant relationship between fish consumption and blood-mercury concentration," wrote the authors of the study, who are professors at Harvard Medical School.

"Regular to heavy fish consumption explained 10 of 11 cases," for those with the highest mercury levels, according to the Harvard paper. Some of those tested were found to have mercury levels more than 10 times the EPA's safe level.

Stern, with the New Jersey environmental-health agency, conducted a survey of mercury levels in pregnant women. He said his agency found patterns in the exposure similar to those reported by Hightower. The top 2 percent of the women tested had mercury levels four times higher than the EPA's safe level.

"We found that if education level is taken as a surrogate for income level, then the most elevated mercury levels were in the upper and lower income brackets," said Stern.

"It's difficult to say how many people have these high mercury levels," said the EPA's Mahaffey. "But we know they are not very hard to find. We find them whenever we start looking."

(This report is part of a continuing series on mercury contamination in our nation's seafood supply. To reach reporter Ben Raines, call (251) 219-5628 or e-mail him at braines@mobileregister.com.)

I wonder if these same results can be found in asian populations due to their large consumption of fish. The trouble with these studies is that they cause panic without verifying the results of these experiments by peer evaluation.

In another article it states that the USA (Univ. Of South Alabama) and the Univ. of Calif will conduct a study along the Gulf coast and then another study will be done (by UC)in California after the Alabama study is complete.

They mentioned amberjack, tuna, grouper, and Chilean Sea Bass. What about shrimp, crab, salmon, and freshwater fish such as trout, catfish, etc.? This is an alarmist article without much real helpful information, like what seafood to AVOID!

Here in Louisiana, authorities are recommending only one serving per month of certain game fish especially bass and crappie from area lakes.

Some lakes are affected worse than others, especially the larger fresh water lakes. I’ve been told that it seems to accumulate faster in the tissues of fish that primarily eat other fish and have long life spans. Bream and sun perch supplement their diets with insects and have relatively short life spans. I've heard one theory of the source of mercury is from contaminated rainwater due to the atmospheric transportation from Asia and China.

Farm raised fish should not have as high a level since most are fed commercial feeds and are only about 1 year old when harvested. Only a hunch on my part if the above theories are correct. I have no idea how seafood lower on the food chain are affected such as clams, shrimp or crawfish.

"What about shrimp, crab, salmon, and freshwater fish such as trout, catfish, etc.?"

This has been a 'simmering' issure around here for quite a while. The original samples were small and initially were intended to check the fish quality around the oil platforms in the Bay and Gulf and when they were found to have high mercury content, the sampling was expanded, it appears to have gone nationwide now.

We have even been given limits of how much freshwater fish it is safe to eat from the waterways around here. The main worry is of the predator fish (trout/bass) that eat other fish and accumulate (concentrate) the methyl mercury in their bodies.

I have not seem crabs, catfish or shrimp mentioned on the 'concern' lists.

I have a 17 acre freshwater lake in my front yard and I quit eating fish from it a few years back and only ate deep water ocean fish.

"I've heard one theory of the source of mercury is from contaminated rainwater due to the atmospheric transportation from Asia and China."

Thanks for the input. I haven't heard about the Asian connection. Early on, at one time or the other, everyone was being blamed. Oil companies, paper mills and etc. I think the problem is more that an 'area' problem. They're even warning about canned tuna now.

Eek! I sure wish I hadn't pinched that murcury from my high school chemistry lab. It was fun to play with though. Maybe that explains why I'm slightly nuts!

On a more serious note, I've eaten a lot of tuna too. And swordfish. I think I will stick with salmon at this point.

"Eek! I sure wish I hadn't pinched that murcury from my high school chemistry lab. It was fun to play with though. Maybe that explains why I'm slightly nuts!"

No kidding. We used to use it to polish all our silver coins. (They wre really silver back then)

I haven’t heard about the canned tuna... I wonder if this is something that has been prevalent all along and we are just now discovering it. Seems to me that it would take decades and decades for the oceans to become affected.

On a more serious note, I've eaten a lot of tuna too. And swordfish. I think I will stick with salmon at this point.

I thought salmon was a carnivore fish and thus should also have a high mercury level.

Actually I suspect that this is the CDC's crisis du jour so that they can get some more funds.

"I haven’t heard about the canned tuna... I wonder if this is something that has been prevalent all along and we are just now discovering it. "

The "drift" that I'm getting is that it isn't new.

Americans die of heart disease. Japanese have healthy hearts in their 70s and 80s when they tend to die of liver cancer. Heavy metals contained in a lifetime diet of ocean fish are the cause. Also the Japanese covet the flesh of giant bluefin tuna that can't be sold in the US due to high levels of heavy metals. When an American fisherman is lucky enough to land a monster bluefin the fish is shipped to the Japanese market.

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