Thyroid cancer in French Polynesia between 1985 and 1995: influence of atmospheric nuclear bomb tests performed at Mururoa and Fangataufa between 1966 and 1974

Background: Between 1966 and 1974, France performed 41 atmospheric nuclear weapon tests in the Mururoa and Fangataufa atolls in French Polynesia. Methods: We performed a geographic analysis of thyroid cancer incidence, us ing data from the cancer registry of French Polynesia, medical evacuation f iles, insurance records and hospital and pathology laboratory files. Results: A total of 153 thyroid cancers were diagnosed between 1985 and 199 5 in the population born before 1976 and residing in French Polynesia. The incidence of thyroid cancer was 2-3 times larger in French Polynesia than i n Maoris of New Zealand and Hawaiians of Hawaii. Based on few cases, a nons ignificant (p = 0.1) increase with decreasing distance between Mururoa and the birth place was observed in women born between 1950 and 1975 for thyroi d cancer. Conclusion: Because the difference between Polynesian and reference populat ions was not larger for Polynesians who were children during the tests than for Polynesians born earlier, as would be expected in the case of radioiod ine contamination, the high thyroid cancer rates in French Polynesia could hardly be attributed to radioiodine fallout. Nevertheless, a surveillance o f the population born close to Mururoa is necessary to confirm or deny the existence of a higher risk of thyroid cancer in this population.