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, using data from the cancer registry of French Polynesia, medical evacuation files, insurance records and hospital and pathology laboratory files.
Results: A total of 153 thyroid cancers were diagnosed between 1985 and 1995 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 in Maoris of New Zealand and Hawaiians of Hawaii. Based on few cases, a nonsignificant (p = 0.1) increase with decreasing distance between Mururoa and the birth place was observed in women born between 1950 and 1975 for thyroid cancer.
Conclusion: Because the difference between Polynesian and reference populations was not larger for Polynesians who were children during the tests than for Polynesians born earlier; as would be expected in the case of radioiodine contamination, the high thyroid cancer rates in French Polynesia could hardly be attributed to radioiodine fallout. Nevertheless, a surveillance of the population born close to Mururoa is necessary to confirm or deny the existence of a higher risk of thyroid cancer in this population.