Measurement of 222Rn concentration levels in drinking water samples from Qena city (Egypt) andevaluation of the annual effective doses

Radon is one of the most important radionuclides, formed fromthe decay of the element radium and more soluble in water. as drinking wateris a vital source of life, control of its quality is critical. drinking watercontaining high radon levels presents a serious risk to human health. thusawareness of radon levels in drinking water is extremely significant to protectagainst radiation exposure. we measured 222rn concentrations in differenttypes of drinking water from qena city, egypt. materials and methods: 111water samples were collected from various sources in qena city (77 samplesof household tap water, 14 samples of bottled water and 20 samples frommunicipal public water supply locations). the 222rn concentrations weredetermined using an alphaguard radon gas analyzer. we calculated annualeffective dose due to ingestion and inhalation of 222rn present in these waters.results: 222rn concentration ranges were as follow: 22.0±0.7 to 118±3 mbq l-1,from tap water 14±3 to 237±5 mbq l-1 from bottled water and 6.0±0.5 to30.0±0.9 mbq l-1 from municipal public supplies. the annual effective dose dueto inhalation and ingestion of 222rn in all types of drinking water measuresless than the recommended reference level of 100 μsv y-1. conclusion: basedon the obtained results, 222rn concentrations in the studied water sampleswere less than the permitted concentrations of usepa and who guidelines.