British Geological Survey, Keyworth, NG12 5GG, UK.
Cancer Epidemiology Unit, Oxford Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Headington, Oxford, OX3 7LF, UK.
J Environ Radioact. 2022 Oct;251-252:106948. doi: 10.1016/j.jenvrad.2022.106948. Epub 2022 Jun 25.
Gamma-rays from naturally occurring radionuclides are a major component of background radiation. They are an important tool for geology and are also important for radiation protection. In this paper we use over a quarter of a million geochemical measurements of concentrations of potassium, thorium and uranium in soils and in stream sediments to estimate outdoor gamma-ray dose rates across Great Britain. The soil concentrations are generally at a depth of 5-20 cm with some at 35-50 cm. Soil measurements will give spatially relatively precise estimates, but as soil data are not available for much of Scotland, stream sediment data are used there. Kriging methods are used to estimate surface concentrations of K, Th and U and dose rates are imputed from these concentrations. Our results are compared with measurement surveys of both outdoor and indoor gamma-ray dose rates. Recently there has been interest in exploring the carcinogenic risks of low dose radiation by investigating associations between childhood cancer rates and doses from natural background gamma radiation. To achieve adequate statistical power, such studies must be so large that it is impractical to assess exposures by direct measurements in the homes of study subjects. Instead the exposures must be modelled. The results presented here will be an important input to such work.
天然放射性核素产生的伽马射线是本底辐射的主要组成部分。它们是地质学的重要工具，对辐射防护也很重要。在本文中，我们使用超过 25 万份土壤和溪流沉积物中钾、钍和铀浓度的地球化学测量数据，估算整个英国的室外伽马射线剂量率。土壤浓度通常在 5-20 厘米的深度，有些在 35-50 厘米。土壤测量将提供相对精确的空间估计，但由于苏格兰大部分地区没有土壤数据，因此在那里使用了溪流沉积物数据。克里金方法用于估算 K、Th 和 U 的表面浓度，并从这些浓度推断剂量率。我们的结果与室外和室内伽马射线剂量率的测量调查进行了比较。最近，人们对通过研究儿童癌症发病率与天然背景伽马辐射剂量之间的关系来探索低剂量辐射的致癌风险产生了兴趣。为了获得足够的统计能力，这种研究必须非常大，以至于在研究对象的家中进行直接测量评估暴露情况是不切实际的。相反，必须对暴露情况进行建模。本文提供的结果将是此类工作的重要输入。
