Living environments, radon

Long-Term Measurements of Radon Concentrations in the Living Environments in Japan A Preliminary Report... 

Aoyama, T., H. Yonehara, M. Sakanoue, S. Kobayashi, T. Iwasaki, M. Mifune, E.P. Radford and H. Kato, Long-Term Measurements of Radon Concentration in the Living Environments in Japan A Preliminary Report, this volume (1986). 

Some years ago it was realized that the indoor inhalation of the short-lived radon daughters constitutes the most important contribution to the radiation exposure of the general population (Unscear, 1982). The working level concept has been introduced in the domestic environment due to the success of the concept in the occupational environment and due to a lack of experimental data on the relative and absolute magnitudes of the transformation and... 

A model has been developed to calculate the size distributions of the short lived decay products of radon in the indoor environment. In addition to the classical processes like attachment, plate out and ventilation, clustering of condensable species around the radioactive ions, and the neutralization of these ions by recombination and charge transfer are also taken into account. Some examples are presented showing that the latter processes may affect considerably the appearance and amount of the so called unattached fraction, as well as the equilibrium factor. 

The decay sequence for Rn-222 is given in Figure 2. Because of the 4 day half-life of Rn-222, it has the time to penetrate through the soil and building materials into the indoor environment. There is some recent evidence that in spite of its short half-life, 55 seconds, Rn-220 can also penetrate into structures in significant amounts (Schery, 1985). However, the data are limited and the extent of the thoron problem is quite uncertain. It is, therefore, the short-lived decay products of radon that are considered to be particularly important in the exposure of the general public and it is these isotopes on which this report will concentrate. 

Quite often you hear only negative stories about nuclear reactions and radioactivity. Radioactivity can mutate DNA molecules and cause cancer. The use of nuclear reactors to produce energy can create nuclear waste, which can harm the environment. Nuclear power plants have been known to have accidents and expose many people to radioactive particles. Radioactive radon gas can be found in the homes that people live in. Nuclear warheads and nuclear weapons can cause mass destruction. On the other hand, there are many uses for radioisotopes that can be beneficial to our lives. In order for a radioisotope to be effective, it must be used properly and in the proper dosages. Some benefits of radioisotopes are described in the following chart. 

In Europe, the average annual effective dose from all sources of radiation in the environment is estimated in 3.3 mSv with indoor doses from radon, thoron and their short-lived progeny accounting for 1.6 mSv of this value (Koray et al., 2013). 

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