Objective To investigate the expressions of lung cancer related genes and miRNA in peripheral blood of the residents surrounding the extremely high radon hot springs in Ruoergai County,Sichuan Province. Methods Peripheral blood samples were collected from the local residents.Expressions of lung cancer related genes (p53,k-ras) and miRNA (let-7a,miR-34a/b) were detected by real-time PCR and the protein expressions of p53 and k-ras were detected by Western blot.Results The expressions of p53 and k-ras mRNA of the residents in high radon area were 0.97 and 1.33 times of the control respectively (t =0.13,-1.12,P ＞0.05),and the p53 and k-ras protein levels were 0.70 and 1.23 times of the control respectively (t =0.72,0.46,P ＞ 0.05).The let-7a of the residents in high radon area was lower (t =1.63,P ＞ 0.05 ) while the miR-34a and miR-34b were significantly higher than those of the controls (t =- 3.20,- 3.32,P ＜ 0.05).Conclusions Based on the expressions of p53 and k-ras gene and miRNA,it can be concluded that the residents surrounding the high radon hot springs received radiation damage.

ObjectiveTo tentatively understand the status of radioactive contamination in nuclear medicine personnel. MethodsA total of 34 radiation staff engaged in nuclear medicine diagnosis and treatment were selected from two hospitals in Shanghai as the survey subjects.Among the 34 medical staff， 8 were nuclear medicine doctors， 14 were nuclear medicine technicians and 12 were nuclear medicine nurses. After surface contamination monitoring was first carried out to confirm that they had no surface radioactivity contamination， whole body scanning was performed with a whole body counter to determine whether they were internally contaminated with artificial radionuclides. ResultsThe α surface contamination was not detected in the nuclear medical staff. The β surface contamination of the nuclear medicine doctors， technicians and nurses was （13.8±0.8）， （14.1±0.8） and （14.0±0.7） times per second， respectively. There were 2， 2， and 4 nuclear medicine doctors who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， 3， 5， and 2 nuclear medicine technicians who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， and 6， 8， and 5 nuclear medicine nurses who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， respectively. The ¹⁸F activity of nuclear medicine technicians was 1 997‒9 401 Bq， and the ^99mTc activity of nuclear medicine technicians and nurses was 3 699‒18 692 and 652‒388 22 Bq， respectively. One nuclear medicine nurse had a ^99mTc activity of 35 389 Bq. According to the preliminary estimation of ¹³¹I internal irradiation dose， the maximum committed effective dose of nuclear medicine doctors， technicians and nurses could reach 0.370， 0.018 and 0.584 mSv， respectively. ConclusionThe nuclear medicine staff are exposed to radioactive contamination， and it is important to monitor and evaluate their internal radiation doses.

Background Based on numerous epidemiological studies, radionuclide ¹³¹I can result in thyroid disease. Objective To study the contamination level of thyroid ¹³¹I in ¹³¹I treatment associated radiation workers in nuclear medicine departments in Shanghai. Methods Based on a general survey on basic situation of nuclear medicine in Shanghai, the level of internal exposure of radiation workers involved in ¹³¹I treatment was assessed with questionnaires and on-site monitoring. A portable γ spectrometer was used for on-site detection, the intake and annual effective dose were estimated according to the measurement results. Physical examination reports were collected for radionuclide positive workers, and chromosome testing was performed. Results There were 579 nuclear medicine workers and 175 were engaged in ¹³¹I treatment in Shanghai. ¹³¹I was detected in thyroid of 18 workers, with a detection rate of 10.3%. Among them, the detection rates of thyroid ¹³¹I in nurses and cleaners were 23% and 25% respectively. The mean measured activity of thyroid ¹³¹I was 306.1 Bq and the maximum measured activity was 3716.9 Bq (nurse). The maximum intake was estimated at 37544 Bq and the median was 786.4 Bq. The average annual committed effective dose was 1.22 mSv and the maximum value was 14.87mSv. The chromosomal aberration rates of all detected workers were negative, and all blood indicators were normal except one with low hemoglobin. Conclusion The annual dose of nuclear medical staff engaged in ¹³¹I treatment does not exceed the national standard limit, but the internal exposure of nurses and cleaners should not be ignored. On the basis of strengthening protection and decontamination, routine internal exposure monitoring should be carried out.