Mahaffey J A, Parkhurst M A, Hui T E, Brownson R C, Alavanja M C
Pacific Northwest National Laboratory, Richland, Washington, USA.
J Expo Anal Environ Epidemiol. 1996 Oct-Dec;6(4):425-37.
In an epidemiologic study investigating influences of life-style and environment on lung cancer risk, CR-39 alpha-particle detectors, identified here as surface monitors, were affixed to subjects' selected household glass, ceramic, or enameled objects to measure residual radioactivity form embedded radon (Rn) decay products. The purpose was to estimate past cumulative indoor Rn concentrations to which the object was exposed to infer past exposures of the subjects. This approach was used to supplement exposure information obtained by methods traditionally used in Rn epidemiologic studies. In addition, surface monitors were affixed to objects of selected study subjects with complete exposure information to evaluate whether surface monitors provided estimates of cumulative past residual Rn exposure comparable to estimates obtained from year-long, ambient alpha track-etch measurements in each present and previous residence. These ambient measurements were time-weighted to estimate integrated exposure of objects and were adjusted for decay and ingrowth so as to be comparable to surface monitor measurements. A regression relationship was estimated between the two estimates of cumulative RN exposure. Surface monitor measurements had a satisfactory correlation (0.63) with adjusted ambient Rn measurements for new, nonceramic objects. Although not included in the study design, factors that might affect use of the technology were also investigated. Regression relationships were compared in graduated smoking environment (as judged by the subjects) to investigate possible differential plate out of radon progeny. In addition, regression relationships for windows were compared with those for other objects to investigate whether there was a significant difference between windows and other objects. It has been suggested that windows may have a higher plate out rate because of locally increased air flow. Results suggested that surface monitor information was useful to fill time gaps in estimates of historical radon exposure data obtained by ambient measurements. Glass samples provided the best correlation. Ceramic materials sometimes provided excessively high radon estimates, probably due to glazes that contained significant uranium or thorium. Due to small sample sizes, investigations of other factors were inconclusive.
在一项调查生活方式和环境对肺癌风险影响的流行病学研究中，CR - 39α粒子探测器（在此被认定为表面监测器）被附着在受试者选定的家用玻璃、陶瓷或搪瓷物品上，以测量嵌入的氡（Rn）衰变产物的残余放射性。目的是估计该物品过去所暴露的室内Rn累积浓度，从而推断受试者过去的暴露情况。这种方法用于补充通过Rn流行病学研究中传统使用的方法获得的暴露信息。此外，表面监测器被附着在具有完整暴露信息的选定研究对象的物品上，以评估表面监测器提供的过去累积残余Rn暴露估计值是否与通过对每个当前和以前住所进行为期一年的环境α径迹蚀刻测量获得的估计值相当。这些环境测量进行了时间加权以估计物品的综合暴露，并针对衰变和生长进行了调整，以便与表面监测器测量结果具有可比性。估计了累积Rn暴露的两种估计值之间的回归关系。对于新的非陶瓷物品，表面监测器测量结果与调整后的环境Rn测量结果具有令人满意的相关性（0.63）。尽管未纳入研究设计，但也对可能影响该技术使用的因素进行了调查。在分级吸烟环境（由受试者判断）中比较回归关系，以研究氡子体可能的不同沉积情况。此外，将窗户的回归关系与其他物品的回归关系进行比较，以研究窗户与其他物品之间是否存在显著差异。有人认为，由于局部气流增加，窗户可能具有更高的沉积率。结果表明，表面监测器信息有助于填补通过环境测量获得的历史氡暴露数据估计中的时间空白。玻璃样品的相关性最佳。陶瓷材料有时提供的氡估计值过高，可能是由于含有大量铀或钍的釉料。由于样本量较小，对其他因素的调查尚无定论。
