Elements of Natural Radioactive Decay Series in Iranian Drinking Water and Cigarettes

Abstract

The uranium ( 238 U) decay series provides the most important isotopes of elements radium ( 226 Ra), radon ( 222 Rn), and polonium ( 210 Po) with half-lives of about 1600 years, 3.8 days, and 140 days, respectively. Although the chemical structure of radium is very similar to calcium, the fact that it produces a radioactive gas (radon) complicates its handling in the laboratory and natural environment. In this study, we used the average concentrations of naturally occurring radionuclide 226 Ra in drinking water at different parts of Iran to estimate the annual effective dose. In the other part of the study, we measured the concentrations of