Radon sources and associated risk in terms of exposure and dose

Abstract

Radon concerns the international scientific community from the early twentieth century, initially as radium emanation and nearly the second half of the century as a significant hazard to human health. The initial brilliant period of its use as medicine was followed by a period of intense concern for its health effects. Miners in Europe and later in the U.S were the primary target groups surveyed. Nowadays, there is a concrete evidence that radon and its progeny can cause lung cancer (1). Human activities may create or modify pathways increasing indoor radon concentration compared to outdoor background. These pathways can be controlled by preventive and corrective actions (2). Indoor radon and its short-lived progeny either attached on aerosol particles or free, compose an air mixture that carries a significant energy amount [Potential Alpha-Energy Concentration (PAEC)]. Prior research at that topic focused on the exposure on PAEC and the dose delivered by the human body or tissues. Special mention was made to the case of water workers due to inadequate data. Furthermore, radon risk assessment and relevant legislation for the dose delivered by man from radon and its progeny has been also reviewed.

Keywords: dose; exposure; human health; lung cancer; progeny; radon; radon risk and indoor air.

Figure 1

Radon’s major entry points into a home. A, cracks in concrete slabs; B, spaces behind brick veneer walls that rest on hollow – block foundation; C, pores and cracks in concrete blocks; D, floor–wall joints; E, exposed soil, as in a sump; F, weeping (drain) tile, if drained to popen sump; G, mortar joints; J, building materials, such as some rock; K, water (from some wells). Reproduced from Ref. (12).

Figure 2

The dose conversion factor (DCF) as function of the unattached radon progeny clusters for working places with different aerosol conditions. Reproduced from data reported by Porstendörfer (29).

Figure 3

The dose conversion factor (DCF) as function of the unattached radon progeny clusters in indoor and outdoor air. wBB, wbb, and wAl are the relative cancer sensitivity distribution of the bronchial, bronchiolar, and alveolar regions of the thoracic lung, respectively, and v = inhalation rate. Reproduced from data reported by Porstendörfer (29).

Figure 4

Radon concentration in water samples versus PAEC measured in two different spa premises. Reproduced from data reported in Vogiannis et al. (54).

Figure 5

Daily exposure in PAEC correlated with radon in water. Exposure was estimate for works and bathers taking into account the time spent in the various spa premises. Reproduced by data reported in Vogiannis et al. (54).

Figure 6

Annual dose received by spa workers correlated with radon in water. Slope corresponds to the pattern of use of the investigated spa. Safety norms could be easily derived from such linear regressions. Reproduced by data reported in Vogiannis et al. (54).