Objective To investigate the concentrations of indoor radon (222Rn) and its daughter products as well as indoor thoron (220Rn) in selected houses in Yuhang district and Sanmen county,Zhejiang province,and estimate their annual effective doses to the population.Methods Solid state nuclear track detectors were used in selected dwellings in Yuhang district and Sanmen county,and the detectors were placed in bedrooms or living rooms.Without changing the ventilation habits of residents,These detectors were continuously placed from March to September in 2009.Results Indoor 222 Rn and 220Rn concentrations in low-rise buildings were the highest among all types of houses.The indoor concentration of 222 Rn had no relation with the building age (F = 0.53,P ＞ 0.05),but that of 220 Rn was dependent on the building age (F = 3.56,P ＜ 0.05).Moreover,the investigation demonstrated indoor 220 Rn concentrations in houses with no decoration were higher than in the houses decorated (t = 2.33,P ＜0.05).The average indoor concentrations of 222Rn and 220Rn in Yuhang district were 32.5 Bq/m3 and 314.3 Bq/m3,respectively,and the annual effective doses were 0.88 mSy and 0.42 mSv respectively.The average indoor concentrations of 222Rn and 220Rn in Sanmen county were 26.8 Bq/m3 and 399.5 Bq/m3,and the annual effective doses were 0.72 mSy and 0.53 mSv respectively.Conclusion The concentrations of indoor 222 Rn in some areas of Zhejiang province are at natural background level,and the concentrations of indoor 220Rn in rural areas are relatively higher.The total annual effective dose from 220Rn and its progeny was larger than that from 222Rn and its progeny by 50 percents.

Objective: To investigate the effects of cadmium exposure on cardiovascular system of occupational workers. Methods: Cross-sectional study was applied to 992 workers in a nickel-cadmium battery plant in November, 2011, of which 749 were cadmium exposed workers and 243 were controls without cadmium and other expose. Urinary cadmium、electrocardiogram (ECG) and blood pressure were examined simultaneously among 992 workers. The risk factors of ECG abnormality rate and hypertension rate were analyzed by Logistic regression. Results: The level of urinary cadmium in cadmium exposed workers was significantly higher than controls (8.89±4.00 vs 1.34±1.18 μg/g creatinine, P<0.01) . Urinary cadmium level in women was significantly higher than men in both exposure and control group (P<0.05) . According to the group of working years, Urinary cadmium level raised with the increase of working years (F=28.272, P<0.001) . The ECG abnormality rate and hypertension rate of cadmium exposed workers were higher than that of control group, the differences were all statistically significant (P<0.01) . The abnormal rate of ECG and the hypertension rate increased with the prolonging of working years and demonstrated dose-response relationship. With the increase of urinary cadmium level, the abnormal rate of ECG and hypertension rate raised (OR=1.11, P<0.01) and (OR=1.15, P<0.01) respectively. Conclusion Occupational cadmium exposure increased the abnormal rate of ECG and blood pressure and therefore damaged cardiovascular system of workers. This study provided base data for protecting health of cadmium exposed workers.

OBJECTIVE: To explore the effect of occupational lead exposure on the relative telomere length(RTL) and mRNA expression of telomere-binding protein POT1-interacting protein 1(TPP1) in peripheral blood of workers. METHODS: A total of 303 workers exposed to lead were selected as the exposure group and 72 administrative logisticians personnel in the same factory as the control group using the simple random sampling method. Their peripheral blood samples were collected and were used to detect the blood lead level by Graphite furnace atomic absorption spectrometry. RTL and the relative expression of TPP1 mRNA by real-time quantitative polymerase chain reaction. RESULTS: The blood lead level of the exposure group was higher [Media(M): 68.2 vs 266.1 μg/L, P<0.01], the RTL was shorter(M: 0.96 vs 0.70, P<0.01), and the relative mRNA expression of TPP1 was lower(M: 0.92 vs 0.51, P<0.01) compared with the control group. Spearman correlation analysis results showed that the blood lead level were both negatively correlated with RTL [Spearman correlation coefficient(r_S) =-0.18, P<0.01], and the relative mRNA expression of TPP1(r_S=-0.19, P<0.01), while the RTL was positively correlated with the risk of RTL shortening and the relative mRNA expression of TPP1 decline was increased in lead exposure(P<0.01). CONCLUSION: Lead exposure can shorten the RTL and reduce the relative mRNA expression of TPP1 in workers. The mechanism may be that lead interferes with telomere repair process by inhibiting the mRNA expression of TPP1.