FACTORS AFFECTING USE OF CR-39 SURFACE MONITOR TECHNOLOGY TO ESTIMATEPAST EXPOSURE TO INDOOR RADON

In an epidemiologic study investigating influences of life-style and e nvironment on lung cancer risk, CR-39 alpha-particle detectors, identi fied here as surface monitors, were affixed to subjects' elected house hold glass, ceramic, or enameled objects to measure residual radioacti vity from embedded melon (Rn) decay products. The purpose was to estim ate past cumulative indoor Rn concentrations to which the object was e xposed to infer past exposures of the subject. This approach was used to supplement exposure information obtained by methods traditionally u sed in Rn epidemiologic studies. In addition, surface monitors were af fixed to objects of selected study subjects with complete exposure inf ormation to evaluate whether surface monitors provided estimates of cu mulative past residential 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 deca y 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 satisfactor y correlation (0.63) with adjusted ambient Rn measurements for new, no nceramic objects.