Tap water as a source of indoor radon in houses

Outdoors, radon is quickly diluted to very low, not problematic concentrations but indoors, it can concentrate significantly. Places that are particularly exposed to an increased radon concentration from water sources are places where water is dispersed, e.g. bathrooms or areas in water treatment facilities. The aim of the paper is to present the calculation of radon escaping from water into the indoor area at home on the example of Mokre village. Mokre is supplied with water from an underground source containing radon 222 (Rn) in concentration of about 200 Bq/L. The obtained data has been compared with WHO recommendation (WHO, 2009) and literature review. Considering that 300 Bq.m(-3) are equivalent to 10 mSv per year, which is equal to receiving approximately an annual full chest CT (computed tomography), the risk resulting from the emission of radon from tap water in Mokre has been assessed to be insignificant.