The correlation between small papillary thyroid cancers and gamma radionuclides Cs-137, Th-232, U-238 and K-40 using spatially-explicit, register-based methods

Abstract

A steep increase of small papillary thyroid cancers (sPTCs) has been observed globally. A major risk factor for developing PTC is ionizing radiation. The aim of this study is to investigate whether geological differences in the prevalence of sPTCs in Sweden are correlated to the deposit of Caecium-137, Thorium-232 (Th-232), Uranium-238 (U-238) or Potassium-40 (K-40) using different Geographical Information System (GIS) methods. Datasets of 812 sPTC patients were combined with the datasets of the total population in Sweden and were layered with the gamma radionuclide deposits. The prevalence of metastatic sPTC was associated with significantly higher levels of Gamma radiation from Th-232, U-238 and K-40. The observed results clearly indicate that sPTC has causative factors that are neither evenly distributed among the population, nor geographically, calling for further studies with bigger cohorts where environmental factors are believed to play a major role in the pathogenesis of the disease.