The highly attractive location for this prospective cohort study is the Faroe Islands in the North Atlantic. These islands form a self-governing part of the Kingdom of Denmark and are located northwest of Shetland, in the ocean between Iceland and Norway. The population is of Nordic origin, and currently about 50,000 people reside on 18 islands covering an area of 1400 square kilometers (slightly less than 550 square miles). The people are highly dependent on seafood, with 44% of dinner meals being based on fish. The Faroese also eat from the top of the marine food chains. The tradition of driving pods of pilot whales ashore at designated beaches has been approved as subsistence whaling by the International Whaling Commission. The whale meat and blubber are distributed locally and are not for sale. Their inclusion in the diet, therefore, depends on local availability and personal preferences, but not on socioeconomic factors such as income. Apart from lamb, potatoes and some dairy products, the majority of the food is otherwise imported from Europe, and the organochlorine exposure from sources other than marine mammals and sea birds is therefore likely to be similar to Scandinavian levels. Thus, apart from the consumption of pilot whales and the reliance on seafood in general, the lifestyle is entirely Western. In contrast to other whale-eating populations, such as the Inuit, the Faroese are therefore comparable to many Western populations.

For the following three reasons,
this population seems highly appropriate:

Range of exposures: The average dietary exposure to PCBs and other persistent organochlorine compounds is higher than in any other Western population studied so far. In addition, exposures range by more than 100-fold, and the lowest exposures constitute a built-in control group. From available statistics on whale consumption and dietary surveys the average Faroese probably eats slightly less than 10 g of blubber per day. (Methylmercury occurs in the lean whale meat, which is often eaten separately, while blubber is frequently eaten with dried fish.) With an average PCB concentration in blubber ranging up to about 30 µg/g, the average daily intake of PCB in the Faroe Islands can be estimated to be up to 200 µg. Intakes of p,p’-DDE are about 30% lower. For comparison, average background daily PCB intakes in most other Western countries are generally assumed to be about 20-30 µg, although possibly somewhat higher in, e.g. the Netherlands. For Great Lakes anglers in the US, Henry Anderson calculated that the average annual PCB intake would be about 46.5 mg, i.e., about 125 µg per day.

Socioeconomic factors are of little importance due to the social homogeneity and the Nordic-type health care system. Faroese women traditionally drink very little alcohol, especially during pregnancy. The proportion of teetotalers is the highest in the Nordic countries, and the average annual alcohol consumption for Faroese women was 1.27 liter in 1994, i.e., roughly corresponding to two glasses of wine per week.

Feasibility of project: Previous work in this population has shown a 90% participation at follow-up at age 7 years. Our studies demonstrated robust effects of prenatal exposure to methylmercury, and they were recently selected by a National Research Council Working Group as the basis for developing exposure limits for methylmercury.

Recommendations to the Government of the Faroe Islands concerning the pilot whale, English translation released 1 December, 2008