Collections > Master's Papers > Gillings School of Public Health > The Occurence of Radon in Some North Carolina Groundwater Supplies

Approximately one hundred small public groundwater supplies in North Carolina were sampled. Analyses for radon-222 were performed by two methods, emanation and a newer liquid scintillation counting (LSC) method. Two primary goals were involved in this work, (1) comparing the two analysis methods listed above and (2) testing for an association between radon concentration in groundwater and the geology of the sampled site. The data show statistically significant differences in radon concentrations measured by the two methods. In 75 percent of the cases the liquid scintillation result was lower, indicating the possible need for refinement of this technique. The precision of liquid scintillation results was tested by comparing dual samples from each site. A paired difference T-test on the dual LSC measurements indicates that the mean difference between dual LSC measurements is equal to zero. Forty three of fifty two differences are less than 10 percent different. The radon concentration data show in general, higher radon concentrations associated with granite and gneiss/schist rock formations over those in mafic and metavolcanic formations. Samples from the coastal plain area had the lowest radon concentrations measured.