Nuclear testing and thyroid cancer

From 1966 to 1974, France conducted 41 nuclear weapon tests in Mururoa and Fangataufa. These tests released a substance called iodine 131, which can be absorbed by the thyroid gland and lead to a type of cancer known as differentiated thyroid carcinoma (DTC). There is an ongoing debate in the medical and public health fields about whether a small amount of nuclear fallout exposure can increase the chances of developing thyroid cancer.

To better understand this, the researchers of this study compared the estimated thyroid radiation exposure and personal and familial history of 229 individuals diagnosed with DTC between 1983 and 2016, to that of 373 individuals who didn't have DTC. To ensure comparability between groups, individuals were matched based on their sex and date of birth. The aim was to gain more insight into what factors increase the risk of developing DTC. The study found that multiple pregnancies and a high body mass index (a measure of weight relative to height) significantly increased the risk of DTC. The study estimated that between 0.6% and 7.7% of thyroid cancers diagnosed in residents of French Polynesia during the time of the nuclear tests could be linked to these nuclear activities. However, no clear association was found between the thyroid radiation dose received and the risk of DTC. The authors suggest the need for further research and monitoring on this topic, noting that this may require a quality cancer registry to become accessible to scientific researchers.

 Related studies have indicated that a diet similar to a traditional Polynesian diet (which involves high seafood consumption) could be associated with a lower risk of thyroid cancer, by increasing dietary iodine intake (Cléro et al. 2012a). Similarly, cassava consumption has also been linked to a decreased risk of developing thyroid cancer (Cléro et al. 2012b).

The full article is available here: (de Vathaire et al. 2023)

Cléro, Énora, et al. "Dietary iodine and thyroid cancer risk in French Polynesia: a case–control study." Thyroid 22.4 (2012a): 422-429. 

Cléro, Énora, et al. "Dietary patterns, goitrogenic food, and thyroid cancer: a case-control study in French Polynesia." Nutrition and cancer 64.7 (2012b): 929-936.