Can screening effects explain increased risk of thyroid cancer among population living near nuclear power plants in Korea?

Abstract

Following reports in Korea of an increased risk of thyroid cancer among those living near nuclear power plants (NPPs) [1], there has been debate regarding the interpretation of the findings. One suggested explanation is the screening effect on thyroid cancer risk. The basic assumption of this argument is that the screening process increases the number of detected thyroid cancer cases in a population, leading to an increase in incidence and relative risk. The Korea Hydro and Nuclear Power Company granted a project to support this assumption to gain an advantage in their legal litigation regarding thyroid cancer cases. However, these circumstances could occur in a limited condition and cannot always happen. Because the screening effect and causality are different issues, we must distinguish between the two different questions. Even if there is a screening effect, it does not mean that the observed increased risk of thyroid cancer does not result from living near NPPs. Therefore, I would like to make a few comments on this issue.