Résumé
Objective To understand the radioactivity level of food surrounding a uranium mine in Xinjiang, to supplement the baseline database of food radionuclides in Xinjiang, to analyze the content of radionuclides and to estimate the internal exposure dose of residents caused by dietary intake. Methods The specific activity of 238U, 232Th, 226Ra, 40K and 137Cs of interest nuclides was measured, statistically analyzed by high purity germanium γ spectrometer, and the annual effective dose of these nuclides was estimated. Results No nuclide 238U was detected in food samples from 2018 to 2020. The average activity concentration and detection rate of other radionuclides were 232Th: 0.428 ± 0.038 Bq/kg (18.3%)、226Ra: 0.477 ± 0.063 Bq/kg (38%)、40K: 162 ± 7 Bq/kg (100%)、137Cs: 0.071 ± 0.011 Bq/kg (29.6%). The annual effective dose of residents due to food radionuclides was about 0.198 mSv. Conclusion The radioactivity level of food in the vicinity of a uranium mining mountain in Xinjiang is within the national standard limit, and the average annual effective dose caused by the diet of residents is consistent with the report of UNSCEAR in 2000. The content of artificial radionuclide 137Cs detected in food samples will not cause harm to the health of residents.
Résumé
Objective To establish the baseline data about gross α and gross β radioactivity in local foods through a preliminary investigation in Urumqi City.Methods The edible parts of six types of foods, including cereals, vegetables, fruit, nuts, meat and dairy food, were pretreated and sampled.MPC 9604 low background o and gross β measuring instrument was used for determination of gross α and gross β radioactivity.Results The natural gross ot and gross β radioactivity in the cereal, vegetables, fruits, nut, meat, dairy food were 0.88-10.80 and 22.20-148.67 in cereals, 1.17-24.24 and 21.41-318.84 in vegetables, 1.44-4.89 and 43.90-112.67 in fruits, 17.49-43.72 and 287.81-747.40 in nut, 3.04 -19.77 and 41.55-164.51 in meat, and 2.07-2.94 and 44.07-59.02 Bq/kg in milk, respectively.Conclusions There are some differences in the gross natural radioactivity between Urumqi and the other provinces and cities due to possible regional differences.In order to further ascertain baseline of natural radioactivity in food in Urumqi, larger sample sizes and more diverse food types are needed for purposes of dynamic monitoring.