Assessment of Radiation Dose from the Consumption of Bottled Drinking Water in Japan.

Activity concentrations of 234U, 235U, 238U, 226Ra, 228Ra, 222Rn, 210Po, 210Pb, 40K, 3H, 14C, 134Cs and 137Cs were determined in 20 different Japanese bottled drinking water commercially available in Japan. The origins of the mineral water samples were geographically distributed across different regions of Japan. Activity concentrations above detection limits were measured for the radionuclides 234U, 235U, 238U, 226Ra, 228Ra and 210Po. An average total annual effective dose due to ingestion was estimated for adults, based on the average annual volume of bottled water consumed in Japan in 2019, reported to be 31.7 L/y per capita. The estimated dose was found to be below the recommended World Health Organisation (WHO) guidance level of 0.1 mSv/y for drinking water quality. The most significant contributor to the estimated dose was 228Ra.

International Rn-222 in drinking water interlaboratory comparison.

A radon in drinking water interlaboratory comparison (ILC) was conducted between eight laboratories in Europe. The majority of the measurement results submitted were in agreement with the assigned value, with a single result deemed questionable. The questionable result does not deviate significantly from the assigned value but the measurement uncertainties associated with this result could be too small. The results from this ILC indicate that there is good agreement between participating laboratories for radon in water measurements.