Co-determination of thorium isotopes in human bone

The contents of 232Th, 230Th and 228Th were given out in 9 cases of bone of inhabitants living in the high background radiation area and on 4 cases of bone of the inhabitants living in the control area in Guandong province. The determination was carried out by means of radiochemistry separation, electrodeposition, followed by alpha-spectrometric measurement using a surface barrier detector. The mean concentrations of 232Th, 230Th and 228Th in the bone of the inhabitants living in the high background area were 13.71 ± 8.33, 17.29 ± 13.23, 23.27 ± 11.24 pCi/kg (wet weight) respectively, while that in the control area were 0.92 ± 0.86, 1.56 ± 0.98, 1.77 ± 1.14 pCi/kg (wet weight) respectively