Lessons learned from conducting disease monitoring in low-dose exposure conditions as a counter-measure after a nuclear disaster

Abstract

The complex disaster of the Great East Japan Earthquake and the Fukushima nuclear accident caused concern about their various health impacts. Many types of intervention are desired as a countermeasure, depending on the phase of the disaster cycle. The importance of developing and applying codes of conduct has recently been emphasized for post-disaster investigations. Thyroid examination as a type of cancer screening survey was launched from October 2011 after the Fukushima nuclear accident as part of the Fukushima Health Management Survey. In this article, we reviewed the results of three rounds of thyroid examination from 2011 to 2018, and summarized the points to consider in the health survey conducted after the Fukushima nuclear accident. Large-scale mass screening by ultrasound thyroid examination resulted in many cancer diagnoses, >200 cases from a large reservoir of thyroid cancer that goes mainly unnoticed without screening. To prevent the harms of such over-diagnosis, we should be aware of the disadvantage of mass-screening based on the expected natural history of thyroid cancer. A change in strategy from mass-screening to individual monitoring is urgently needed according to international recommendations that are opposed to thyroid ultrasound cancer screening even after a nuclear disaster. To guarantee autonomy and informed choice on post-disaster disease monitoring for residents in a disaster-zone, it is important to set protocol participation and on a voluntary code of conduct basis.

Young people’s perspectives of thyroid cancer screening and its harms after the nuclear accident in Fukushima Prefecture: a questionnaire survey indicating opt-out screening strategy of the thyroid examination as an ethical issue

“…Four rounds of the thyroid ultrasound examination have been conducted in Fukushima Prefecture over the past 10 years, and a fifth round of opt-out screening is progressing despite these global trends. This examination has resulted in more than 200 thyroid cancer diagnoses (116 in the first round, 70 in the second, and 31 in the third) [ 20 ]. The observed age-specific prevalence of thyroid cancer was more than 30 times the expected rate in the first round, based on previous cancer registry data showing rates before screening [ 21 ].…”

An Ethical Issue After the Nuclear Accident in Fukushima: Young People’S Perspectives of Thyroid Cancer Screening and its Harms

“…However, four rounds of the thyroid ultrasound examination have been conducted in Fukushima over the past 10 years, and a fth round with opt-out style screening is progressing despite these global trends. This examination has resulted in more than 200 thyroid cancer diagnoses (116 in the rst round, 70 in the second, and 31 in the third) [15]. The United Nations Scienti c Committee (UNSCEAR) concluded that the signi cant increase among screening participants relative to that expected was because of overdiagnosis and not the result of low radiation dose exposure [5].…”