Evaluation of radon in bottled drinking water and computing associated radiation doses to assess health risks

Radon (²²²Rn), a naturally occurring radioactive noble gas produced by the decay of uranium (²³⁸U), is present in rocks, soil, and groundwater. ²²²Rn dissolves readily in groundwater; therefore, it contaminates drinking water supplies, including bottled water, which increases internal radiation exposure through ingestion. Humans are exposed to naturally occurring radioactive materials (NORMs) in rocks, soil, and water. Variations in atmospheric, geological, and physical features result in an uneven distribution of radionuclides on the surface due to the uneven natural presence, transport, deposition, accumulation, and retention of radionuclides. Excessive ²²²Rn levels beyond the permissible limit in the environment can cause lung cancer. The primary aim of this study is to determine the ²²²Rn concentrations in commercially available bottled drinking water. A RAD7 H₂O detector was used to measure ²²²Rn concentrations in bottled water samples from 31 brands, each comprising three samples from various Saudi Arabian firms, to assess the potential effects of radioactive water pollution on human health from radiation exposure. Determine the population's annual effective radiation doses from ²²²Rn ingestion, baseline data for radiological quality control, and evaluate the possible health effects of ²²²Rn exposure from bottled drinking water. The dose contribution to different organs received by the ingesting and breathing routes has been examined. The study evaluates the ²²²Rn levels in the water, which ranged from 0.13 to 0.39 Bq.L^-1. Radiation doses were calculated to assess potential health risks associated with ²²²Rn exposure. The consumption of dissolved radionuclides in bottled drinking water contributed to an annual effective dose ranging from 1.28 to 3.84 µSv.y^-1, 2.23 to 6.69 µSv.y^-1, and 6.97 to 20.97 µSv.y^-1, respectively, for adults, children, and  infants with an average value of 1.69 µSv.y^-1, 2.95 µSv.y^-1, and 9.24 µSv.y^-1. The study found that the yearly effective doses from bottled waters are below the WHO's recommended limit of 0.10 mSv.y^-1. The data was compared to worldwide standards provided by several sources. The results are below both the USEPA's 11 Bq.L^-1 and the WHO's recommended level of 100 Bq.L^-1. This investigation found low levels of radioactivity in all water samples tested in the Kingdom of Saudi Arabia.