Determination of uranium at ultra trace level in packaged drinking water by laser fluorimeter and consequent ingestion dose

Precise and accurate estimation of natural radioactivity is essential in order to appraise the radiation dose to the member of public due to various intakes. In the present study, an attempt has been made to estimate the uranium content in packaged drinking water by laser induced fluorimetry and then to calculate the committed effective dose. Sixty packaged drinking water samples of different brands were analysed for uranium content. The total uranium content in these samples was found to be in the range of 0.04–3.88 µg l-1. The concentration of uranium is comparable with other reported worldwide values except a few high values such as 0.5–6000 µg l-1 in Finland, 0.1–28 µg l-1 in China, 0.1–40 µg l-1 in Switzerland and 0.04–1400 µg l-1 in Jordan and much lower than the drinking water limit of 15 µg l-1 (WHO, 2004) and 30 µg l-1 (USEPA, 2000a). The radiation dose due to uranium ingestion through packaged drinking water was found to vary from 0.08–3.19 µSv y-1, with an average dose of 1.21 µSv y-1.