Concentration of 226Ra in Human Teeth

Abstract

226Ra concentrations in human teeth from several cities, mainly Tokyo, Japan, were determined with emphasis on the measurement of low-level 226Ra by alpha-ray spectrometry following chemical separation. No appreciable differences in 226Ra concentration were found among various permanent teeth samples of different age groups in Tokyo. The mean 226Ra concentration for Tokyo was 0.51 +/- 0.06 mBq (g Ca)-1. 226Ra concentration [mean: 0.67 +/- 0.11 mBq (g Ca)-1] in teeth in western regions of the country was statistically higher than that [mean: 0.48 +/- 0.09 mBq (g Ca)-1] in eastern ones. The mean 226Ra concentration [0.51 mBq (g Ca)-1] in teeth from Tokyo was less than the concentration [1.11 mBq (g Ca)-1] reported for vertebral bone samples of this city.

226Ra concentration in the teeth of habitants of areas with high level of natural radioactivity in Ramsar

“…bone, were mentioned in a few papers. Yamamoto et al (1994) collected the permanent teeth of inhabitants of different cities of Japan. They reported the 226 Ra activity of 0.23 AE 0.04 mBq g À1 (ash) in the teeth of residents of Tokyo.…”

“…The mineral part of teeth tissue is formed of biologic apatite crystals such as hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 (Nanci, 2003). 226 Ra can replace calcium and enter the hydroxyapatite structure (Yamamoto et al, 1994). Ion exchange can take place when mineralization begins in deciduous and permanent teeth (the 12th week of embryonic development and during the fourth month of post-birth, respectively), and continues until the time of enamel completion (11 months for deciduous and 13 years for permanent teeth; Nanci, 2003).…”

“…Henshaw et al (1994) studied the uptake and spatial distribution of the natural a-radionuclides in teeth and reported the transmission of 226 Ra to the pulp and dentine through systemic blood circulation. 226 Ra in teeth is rarely metabolized after substitution and completion of teeth (Yamamoto et al, 1994). After radium reaches teeth structure, it causes the splitting of the joints and ionization in both organic and mineral parts.…”

“…Penna-Franca (1977) reported 0.76 AE 0.30 Bq kg À1 (ash) as the concentration level of radionuclides in the teeth of inhabitants of the HLNRAs in Brazil. Yamamoto et al (1994) measured the activity of 226 Ra in the teeth and bones of inhabitants at different locations in Japan. They reported the mean value of 0.23 AE 0.04 and 0.41 AE 0.22 Bq kg À1 (ash) as the activity of 226 Ra in the teeth and bones of inhabitants of Tokyo, respectively.…”

Measurement of gross alpha and gross beta activity concentrations in human tooth

“…But, Penna-Franca (1977) reported 0.76 AE 0.30 Bq kg À1 (ash) as the concentration level of radionuclides in the teeth of inhabitants of the HLNRAs in Brazil. Yamamoto et al (1994) measured the activity of 226 Ra in the teeth and bones of inhabitants at different locations in Japan. They reported the mean value of 0.23 AE 0.04 and 0.41 AE 0.22 Bq kg À1 (ash) as the activity of 226 Ra in the teeth and bones of inhabitants of Tokyo, respectively.…”