Dr. Pal Weihe is chief physician at the Department of Occupational and Public Health in the Faroese Hospital System. He studied epidemiology and occupational medicine in Denmark for 20 years before returning to his native Faroe Islands, where he spent the next 20 years studying the effects of mercury, a result of the Faroese tradition of eating whale meat.
In this interview with FRONTLINE/World reporter Serene Fang, Weihe talks about how his initial findings released in 1997 were received by a small protective community that has been hunting and eating pilot whales for more than a thousand years. Weihe's study is now the benchmark for the U.S. Food and Drug Administration (FDA). He explains here what his study of children and adults on the islands revealed.
Q: Where did the idea for the study come from?
A: Dr. Pal Weihe: It started 22 years ago. I was in Denmark for educational purposes, in Odense, at the Department of Occupational Medicine. Professor Philippe Grandjean was also there. We started talking about what we could do in the Faroes when I went back. It ended up that mercury was perhaps an issue in the Faroes; there had been some indications in the press that the pilot whale was contaminated with mercury.
The World Health Organization [WHO] recommended that longitudinal epidemiological studies should be done to find out more about methylmercury toxicology in low-exposure areas -- that means lower than the exposure in cases such as Minamata [in Japan] and in Iraq. [Read more about the Minamata mercury poisoning and a case in Iraq in "Mercury Disasters." sidebar] We thought perhaps the Faroes was a suitable setting for doing this kind of epidemiological study because Faroese society is stable, homogeneous and conservative.
Q: What did you know about mercury at the start of this study?
A: We knew mercury was a toxic substance -- there's no doubt about that. We saw in Minamata that a lot of newborns were harmed. The lesson learned from Minamata and from Iraq was that prenatal exposure [to mercury] was more critical than postnatal In other words, when fetuses are exposed to the same concentrations as adults, there are more harmful effects.
What we saw in Minamata and Iraq was that the brain was affected. You could see that people got neurological diseases. You can go to Minamata today and see people with the toxic effects on their brains because of exposure [from] when they were fetuses and adults. That is not the case in the Faroes -- here, we are talking about a factor level of a thousand, perhaps less, than the highly exposed people in Iraq and Minamata.
Q: What did you expect to find among Faroese children?
A: We did not expect to see any signs of mercury poisoning, like cerebral palsy. What we were going after were subtle effects on neurodevelopment -- mental ability, language, reaction time, things like that. But we did not expect to identify any single child intoxicated by mercury. In epidemiological terms, the plan was to examine a large group of children and mothers and, on a group basis, make a statistical analysis to see if exposure to methylmercury played a role or not.
We had to wait many years to identify the results. It is one thing to measure the methylmercury in the umbilical cord or in a motherís hair or milk, but you cannot establish the toxic effects on children until several years later [as they develop]. We found that the best age to begin testing is around preschool age -- in the Faroes, thatís just before the age of 7.
Q: How did you feel about returning to the Faroes after so many years in Copenhagen?
A: I had been living in Denmark for 20 years, becoming a specialist in occupational medicine, and I knew all the time that I wanted to go back [to the Faroes]. My wife and children also wanted to go back. I guess you have a kind of salmon instinct to return to the place where you were born. There is also a desire to protect a society that is dear to you. You are proud to be a Faroese, you are proud of your nation. It’s an exclusive club of 50,000 souls. So every single person counts.
Q: Has the controversy over the pilot-whale hunt affected your research?
A: I chose to specialize in marine pollutants and the exposure due to pilot-whale consumption. Itís an old phenomenon in the Faroes, which has been under heavy attack from the outside world because whaling is not considered a decent way to behave. On the other hand, the Faroese have done this for centuries. We have detailed records on every whale slaughter done in the last 300 or 400 years. The catches are divided among the community in a socially correct way. They are no commercial interests, and whaling to the Faroese population is defended because the pilot whales are plentiful in the North Atlantic. There are one million whales, according to biologists, and we are slaughtering perhaps 1,000 per year.
On one hand, I wanted to support my people and their right to do these things. On the other hand, as a physician, I knew that this old habit was perhaps dangerous to the populationís health and especially to a pregnant woman, because thereís a very high concentration of methylmercury in the meat and muscle tissue of the pilot whale. Around half of this concentration comes from anthropogenic sourcesÖ
A: Yes. Manmade sources like coal-burning power plants from far away places in China, in America, in Europe. That pollution is distributed into the atmosphere and ends up partly in the oceans, making its way to the seabed. It starts multiplying in the food chain and ends up in sea mammals like the pilot whale, which is a toothed whale. These are then eaten by the Faroese population, including pregnant women.
For me, it was a real challenge because the phenomenon [of eating whale meat] is so appreciated here. So to come with this message that perhaps it is dangerous -- and itís not only mercury but PCBs [polychlorinated biphenyls] and DDTs [dichloro-diphenyl-trichloroethanes] and a lot of othersÖ. And the concentrations of PCBs in women in the Faroes, for example, is sky high.
Q: So how did the study begin?
A: The first samples were taken in a pilot phase during Christmas 1984, and they were actually from my family. Grandjean and I wanted to see what the actual exposure levels were, and they turned out to be quite high. We decided to make a pilot study in a fishing village in Eysturoy called LeirvŪk We invited all the women between 20 and 50 to give a blood sample. Then, we decided to go a step farther because those exposure levels were so high.
We could now begin to answer the question that the WHO had posed: What are the subtle effects of methylmercury in low-exposure areas? We applied for research money and began the study in earnest in March 1986. We asked all three Faroese hospitals to participate. I think it is characteristic of the Faroese that there has always been a high willingness to participate. If you explain what you want to do thoroughly and they understand your purpose and the consequences of it, people see it as an opportunity to contribute. By the end of 1987, we had a cohort of 1,023 mother-child pairs.
The first main testing was done when children were 6, just before attending school. We did as thorough an examination as we could -- both psychologically and neurophysiologically. What I hoped we would find was nothing. Then as a public health official, I could say to the population that we did not find any harmful effects, even after they had been eating contaminated meat from whales. But in neuropsychological testing, we found impact on several fronts. In the brain, for example, in reaction time, in memory, in language. In other areas, we saw indications of impairment. Not a large impairment, but they all went in the same negative direction.
Q: In the Faroes, what was the reaction to your research findings?
A: After we published our first findings in 1997, the public health authorities in the Faroes [began advising] pregnant women, women who plan to become pregnant, and lactating women not to eat whale meat or blubber because it contains pollutants. The study recommendations received a lot of attention. Some people saw it as giving in to the external pressures to stop the Faroese from hunting pilot whales, so it was difficult to keep that message clean. We had to stress that this was a health recommendation and in no way an interference in the discussion of whether the Faroese should slaughter pilot whales or not.
Even though I was concerned how the recommendations would be received, people have really followed the advice very well. Of course, a motherís interests are first and foremost the health of her child. All the other political stuff about hunting whales is not so relevant to her.
Q: What did critics say of the findings?
A: One of the main criticisms against eating less pilot-whale meat and blubber was what is the alternative? Will it be fast food? Will Burger King or McDonaldís fill the empty space?
Itís an issue across the circumpolar area. The discussion in Greenland, for example, is that if the people of coastal Greenland or northern Greenland or Canuck or eastern Greenland stop eating sea mammals, whatís the alternative? There is nothing else there, other than imported food.
Q: Was there reluctance to accept the findings among older Faroese?
A: The pilot-whaling tradition has been so central in Faroese culture and the attacks from outside have been so severe that there was every reason to think that the Faroese would protect that tradition energetically. But I must say I am quite astonished how well -- and how rationally -- they have balanced the right to keep an old habit that is an important symbol of cultural identity with the negative health aspects. The critical voices that I have heard are no more than I expected. They are actually much less.
Q: What about your own views on whaling?
A: When I was a child, slaughtering pilot whales in my place in Sorvagur [was allowed]. It was done on an island outside [the bay], called Tindholmer. When you see it, watch it happen, all the blood comes out. That was a very dramatic event, and it made a very big impression on me. When you were a teenager, you took part -- and so I did. It was one of the big memories from my days in Sorvagur -- this drama around the slaughtering of a couple hundred whales in the night, [with] the stars in the sky and all that.
I myself have participated, even recently, in pilot-whale slaughters. Thatís because I want to show the public that I am not against the habit as such. My point as a public health person is to tell people that if your consumption of this food item is considerable, your risk of imposing harm on yourself and your offspring will rise.
People often ask me, "How many children have been harmed by this? And how many mercury patients do you have?" People are confused when I tell them I have none. There is not a single person on the island who, to our knowledge, has been disabled or harmed in a way that we could identify in a clinical way. Detecting cerebral palsy, for example, itís not the case. What we have done on a group basis is identified subtle effects. We have measured, for example, the reaction time in 1,000 children, and we can see that methylmercury exposure in the motherís womb is associated with the ability to react fast in a negative way. Of course, there are other genetic factors, some children are naturally more gifted than others, but because this is a group study, itís possible to identify that the mercury is adding an extra negative load to the whole group.
Q: If, as you say, the results are so subtle, why bother with a study?
A: In a modern society, you can have other factors. And here, with mercury, you have identified one small part, but the sum of those parts is a big whole. What we have identified, society can eliminate without big sacrifices, so we should do it. I can in good conscience say to a young woman, "Please donít eat mercury-contaminated pilot-whale meat, because you have so many alternatives. You can eat cod and haddock and halibut or salmon -- or any of the other precious foods that we produce in this country." I am not telling her what to do. I am giving her a tool to reduce her exposure to these pollutants.
The half-life of mercury in a motherís blood is around 45 days. That means if you donít eat any pilot-whale meat for 45 days, then more than likely the concentrations of mercury in your blood will be halved and that means the exposure to your child in the womb will be halved.
Q: What other important information has the study revealed?
A: TIn a dietary survey taken in 1982 in the Faroes, the average daily consumption of pilot-whale meat in the adult population was around 12 grams per person per day -- 7 grams of that from blubber.
In 2000 and 2001, we asked pregnant women to describe their dietary habits. And to our surprise, they reported that their intake of pilot-whale meat was next to nothing. In 2001, consumption was down to around 1 gram of pilot-whale meat and a half-gram of blubber. When we took blood samples and analyzed them for methylmercury, [we saw] very low concentrations -- around 1 microgram per liter. The median concentration in cohort 1, taken in 1986 and 1987, was 24 in the umbilical cord blood. That means a drop from 20 to 1, and I think [those low concentrations] were a result of these recommendations.
Q: What have your more recent research efforts discovered?
A: After the initial study, we designed a follow-up examination for 14-year-olds, using the same cohorts we had established in 1986 and 1987. I was still hoping that the findings among the 7-years-olds would have disappeared. To my disappointment, they had not. We saw the same patterns of neuropsychological effects with the 14-years-olds, as we did at aged 7. It meant that the negative effects on their brains had not disappeared and had, instead, become chronic. We are now planning to raise money to begin a new study at 21 years of age.
Q: What about detections of other contaminants, such as PCBs?
A: When we looked at the PCBs and compared 2000 and 2001 blood levels with the levels taken in í94, there was no significant reduction. This was disturbing. These substances are much more persistent, meaning that they accumulate in your body and will stay there for a long time. Unlike with mercury, itís not enough to say to a woman, "When you intend to become pregnant, reduce your mercury intake and within 45 days you can bring down the levels very fast." These [other] substances are persistent, much more persistent. But we donít know really what the toxicology of these substances is [or] how harmful [they] are in the concentrations seen in the Faroes population.
Q: How have these studies taken a toll on the Faroese families taking part?
A: It has been a real sacrifice for them. It is very demanding on parents -- and the children -- but they feel it is important. I see mothers who truly suffer when their child is crying because we have to draw blood, and itís not always so easy. Nevertheless, they come back over and over again. I know they feel an opportunity to contribute to research that can be beneficial to the rest of the world. They feel it is a good cause. My problem is that they are so loyal to our studies that we have to protect them against misinterpretations.
Q: What do you mean?
A: Sometimes journalists write that mercury in the Faroes has made the population unintelligent. And of course, this is rude and upsetting. People read it on the Web, they come back to me and say, "Why are people saying this?" I try to tell them that it is a misunderstanding. I try to explain thoroughly to journalists what we have found. I try to obtain a guarantee that they understand the study -- not because I want to interfere in what they report, but I want the underlying scientific facts to be known. Thatís the best way to protect the members of the study. In a way, you become a father to them.
Q: In assessing the neurological impact of mercury, why didnít you use intelligence testing?
A: Early on in our study protocol, we were discussing what tests we should use. Should we use global tests, intelligence tests? IQ measurement? We did not use an IQ test, because we were not interested in comparing individuals in one global measurement. After a lot of discussion, we decided that the most reasonable thing to do was to describe the different domains of the brain [and] not try to compose the whole thing in a single figure. We have a description, for example, of memory, language, visual-spatial ability, reaction timeÖ. That means I am not reporting back to the family that a childís intelligence is this or that (for example, 110 or 95). We do not do that -- we are describing the different abilities in the different domains.
We realized one child could be good at one thing, while that same child might not be so good in other areas. We wanted to split the testing up as much as possible. We looked at the results in each individual test, and afterward thought perhaps we could compose all these results into one single picture. To some extent, we have done that. But pure IQ is not important to us. What has been important is how mercury relates to memory -- long-term memory, short-term memory. How mercury is related to reaction time. Just putting the whole thing into one pot, mixing it up and coming out with a single number has no relevance to us.
Also, we did not want to use an IQ test because itís potentially stigmatizing. Itís much more gentle to describe different abilities, because an IQ is quite an abstract thing for many people. You can be smart in so many fields.
Q: Do you eat pilot-whale meat?
A: When people ask me that, I say, "Yes, I do." If people serve it to me, I will eat it. But I must confess, in my home, we have very little pilot-whale meat. I guess I have not been in the spot when the catch has taken place -- itís not in my freezer or storages simply because I have not been in the right place at the right time.
Have I served it to my daughter or my son? Very little. For some people, the decision to eat or not is absolute. Itís yes or no in a religious way. That is not our message. Our message is, "Please take care of how large your mercury or PCB intake is," and to remind them that one of the major sources [of mercury] is the pilot whale and how that can be managed. I have never asked people to come to a full stop. I have always asked them to reduce or to abstain temporarily. To me, it has been important in the public health message not to be absolutist. It is about communicating risks and how to manage risks.
Q: What do we know about the source of the pollutants themselves?
A: The pollution showing up here is, of course, external phenomena -- itís a modern pollution that is manmade, arriving in the last 50 to 100 years. Of course, we are part of the Western world, but to those people who have stuck to the tradition of eating pilot whales, this is irrelevant. The important fact is our food has been contaminated and we cannot do anything about that now -- it is out there in the big oceans. What we can do in the Faroes -- and what we have done -- is reduce the intake and change our habits. Itís important that weíve had the chance to document that these substances are dangerous to humans -- that we are able to present this bill of human health to the international community. It means the more or less abstract concept of pollution has been made very concrete, very specific through these studies.
It's important, too, for the participants that through this research, they are able to send a message back to the world that says, ďLook, we are paying a price -- our children have suffered under the toxic load of methylmercury and other persistent organic pollutants.Ē I think that has been important to some people. Otherwise, we would just say we are heavily exposed, but nobody would know if we have paid a price or not. We now have documented it ourselves and to the international community -- we have paid a price. Whether it is big or small, I shall not say. But we have identified a toxic effect on our children. And we have paid a price: We have been forced to change some dear dietary habits, which are an important part of our Faroese identity.
My point is that global pollution is a very abstract thing. We donít put a face on it. But here in the Faroes, we have shown that there is a population that has actually paid a price for pollution. And we have tried to estimate the size of it.