Radiological study of sachet-packaged water: a case study of the products in Owo local government area of Ondo State, Nigeria

The radioactivity levels of some sachet-packaged drinking water produced and used in Owo, a local government area of Ondo State, Nigeria, were measured. The activity concentrations of Ra-226 varied between 0.6 +/- 0.2 Bq L-1 and 11.6 +/- 3.2 Bq L-1 with an arithmetic mean +/- standard deviation of 6.6 +/- 3.6 Bq L-1, the activity concentrations of Ra-228 varied between 4.5 +/- 2.1 Bq L-1 and 18.6 +/- 6.1 Bq L-1 with an arithmetic mean +/- standard deviation of 12.2 +/- 4.5 Bq L-1 and that of K-40 varied between 22 +/- 6 Bq L-1 and 142 +/- 41 Bq L-1 with an arithmetic mean +/- standard deviation of 68 +/- 45 Bq L-1. K-40 was not detected in one sample. The resulting annual effective doses due to ingestion of the radionuclides Ra-226 and Ra-228 in the water samples varied between 2.4 mSv and 11.5 mSv with an arithmetic mean +/- standard deviation of 7.5 +/- 2.8 mSv, which are higher than the recommended standards of WHO and UNSCEAR. Therefore this study shows that it is not radiologically advisable to consume any of the sachet drinking water studied.