查看文章

Study is made of the radioactivity in the beach sands of Langkawi island, a well-known tourist destination. Investigation is made of the relative presence of the naturally occurring radionuclide ⁴⁰K and the natural-series indicator radionuclides ²²⁶Ra and ²³²Th, the gamma radiation exposure also being estimated. Sample quantities of black and white sand were collected for gamma ray spectrometry, yielding activity concentration in black sands of ²²⁶Ra, ²³²Th and ⁴⁰K from 451 ± 9 to 2411 ± 65 Bq kg^− 1 (mean of 1478 Bq kg^− 1); 232 ± 4 to 1272 ± 35 Bq kg^− 1 (mean of 718 Bq kg^− 1) and 61 ± 6 to 136 ± 7 Bq kg^− 1 (mean of 103 Bq kg^− 1) respectively. Conversely, in white sands the respective values for ²²⁶Ra and ²³²Th were appreciably lower, at 8.3 ± 0.5 to 13.7 ± 1.4 Bq kg^− 1 (mean of 9.8 Bq kg^− 1) and 4.5 ± 0.7 to 9.4 ± 1.0 Bq kg^− 1 (mean of 5.9 Bq kg^− 1); ⁴⁰K activities differed insubstantially from that in …