RADIATION BIOLOGY OF SIMULATED RADON DAUGHTER ALPHAS

模拟氡子体 α 的辐射生物学

• 批准号: 2871739
• 负责人: ERIC J HALL
• 金额: $ 95.42万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-08-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2871739
• 关键词: alpha radiation; biophysics; cancer risk; clinical research; human data; linear energy transfer; neoplasm /cancer epidemiology; radiation carcinogenesis; radiation related neoplasm /cancer; radiobiology

Plausible estimates of the annual US mortality linked to domestic radon exposure vary from 0 to 40,000. This wide range is largely a result of uncertainties in the various assumptions and extrapolations necessary to produce an epidemiologically-based risk estimate. This project brings together and links three projects in experimental radiation biology, within a strong theoretical framework provided by a modelling project; it is specifically targeted ar reducing uncertainties in extrapolation, particularly from high to low dose, from high to low dose rate, and between different radiation qualities. Based on a detailed analysis of the sources of uncertainty in estimating domestic radon risk, our five goals are 1) Understanding how to extrapolate radon risks down to very low doses, corresponding to an average of less than one a particle per cell; 2) Assessment of appropriate quality factors for radon; 3) Evaluation of the significance of a-particle exposure time; 4) Investigation of the interaction between a-particles and other lung carcinogens; 5) Investigation of characteristic biomarkers of a-particle exposure. Because of the stochastic nature of the endpoint of interest in humans (lung cancer), our three in vitro experimental projects focus on mutation, chromosomal aberration and oncogenic transformation. In each case our overall aims are guided by the needs of domestic radon risk estimation, and the modelling project is designed to analyze the experimental results and apply the conclusions to risk estimation. A key component of this proposal is the single-particle microbeam, which makes it possible to deliver exact numbers of a-particles to individual cells, including a single particle. In the last year, the speed at which we can deliver known numbers of a particles to single cells has increased by an order of magnitude. The central issue is to assess cancer risks in the domestic situation where cells of the bronchial epithelium are essentially never traversed by more than one a-particle in a life-time, by extrapolation from underground miner data where multiple traversals are common. The focus of this proposal is to use the microbeam with all of the biological systems listed above, further complicating factors being dose prolongation and the presence of other carcinogens.

美国每年与国内氡气相关的死亡率的合理估计 曝光量从 0 到 40,000 不等。 这种广泛的范围很大程度上是由于 各种假设和推断的不确定性 产生基于流行病学的风险评估。 这个项目带来了 将实验辐射生物学的三个项目结合在一起并联系起来 建模项目提供的强大理论框架；这是 专门针对 AR 减少外推的不确定性， 特别是从高剂量到低剂量、从高剂量率到低剂量率以及之间 不同的辐射质量。 基于对来源的详细分析 由于估计国内氡气风险存在不确定性，我们的五个目标是 1) 了解如何将氡气风险推断至极低剂量， 相当于每个细胞平均少于一个颗粒； 2) 评估氡气的适当质量因素； 3）评估a粒子暴露时间的显着性； 4）a粒子与其他肺相互作用的研究 致癌物质； 5）a粒子暴露特征生物标志物的研究。 由于人类兴趣终点的随机性 （肺癌），我们的三个体外实验项目重点关注突变， 染色体畸变和致癌转化。 在每种情况下我们的 总体目标以国内氡风险评估的需要为指导， 建模项目旨在分析实验结果并 将结论应用于风险评估。 该提案的一个关键组成部分是单粒子微束，它 使得向个体传送精确数量的a粒子成为可能 细胞，包括单个颗粒。 去年，速度 我们可以向单个细胞传递已知数量的粒子已经增加 提高了一个数量级。 核心问题是评估癌症风险 国内支气管上皮细胞情况 一生中基本上从未被超过一个a粒子穿过， 从多次遍历的地下矿工数据中推断 常见的。 该提案的重点是将微束与所有 上面列出的生物系统，进一步复杂化的因素是剂量 延长时间和其他致癌物质的存在。