The collective dose equivalent in evaluated region of bone-coal power stations and bone-coal shafts

During 1991-1993, the radioactivity levels of the bone-coal mines were investigated in Hubei, Hunan, Ji-angxi, Zhejiang and Anhui Provinces, respectively, where the reserve of bone-coal is about 90% of our country’s total reserve. The annual additional collective dose equivalent within 80km evaluated region of bone-coal power stations in Nijiangkou and Anren is 1.7 and 1.9 man·mSv, respectively, and that of Zhuantanyan bone-coal shaft is 1.4 man·mSv. The collective dose equivalent caused by bone-coal cinder brick produced for 25 years in the five prov-inces is 1.6×105 man Sv.

Estimation of the resident’s additional dose in bone-coal mining areas of the five provinces

This paper introduces the resident’s additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the car-bide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and An-hui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background ra-diation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environ-mental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and min-ers is 1.9—6.8 mSv, 0.5—2.0 mSv and 8.2—71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respec-tively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%.

Investigation on natural radionucildes levels in multiple media in bone-coal mine areas of five provinces

This paper reports methods and results of the investigation of natural radionuclides levels in multiple me-dia in the bone-coal mine areas in Hubei, Hunan, Jiangxi, Zhejiang, and Anhui Provinces. In the studied bone-coal mine areas, the specific activities of 238U and 226Ra in the soil samples were 0.37 and 0.24 Bq/g, respectively; the spe-cific activities of 226Ra in the samples of bone-coal, bone-coal cinder and bone-coal cinder brick (BCCB) were 1.3, 1.4 and 0.9 Bq/g, respectively. In the water samples collected from the bone-coal mine areas, the average concentra-tions of natural uranium and 226Ra were 33μg/L and 58 mBq/L, respectively, while in the water samples collected from outside the bone-coal mine areas, they were 3.4μg/L and 45 mBq/L, respectively. In addition, the specific activi-ties of 238U and 226Ra in air aerosol samples from the bone-coal mine areas were 0.6 and 0.5 mBq/m3, respectively.

Effect of Antimony on Physiological Responses of Green Chinese Cabbage and Enzyme Activities of Allitic Udic Ferrisols

High concentrations of antimony(Sb) in soils and vegetables can cause potential health risk. However, the effect of Sb on the growth and response of crops are not well known and to date, there is still no Sb limit standard for Allitic Udic Ferrisols in China. In this study, a greenhouse experiment was carried out to investigate the effect of antimony(Sb) on biomass, physiological performances,and macro- and micronutrient element concentrations of green Chinese cabbage(Brassica chinensis L.), as well as enzyme activities,in Allitic Udic Ferrisols from Hunan Province, China. Antimony was supplied at rates of 0(control), 2, 5, 10, 20, and 50 mg kg-1and thus with the background value of 1.0 mg kg-1, the Sb concentrations in the treated soil samples were 1, 3, 6, 11 21, and 51 mg kg-1, respectively. The results showed the leaf biomass and ascorbic acid content of cabbage significantly(P < 0.05) decreased by 30.6% and 48.3%, respectively, and soil urease and dehydrogenase activities also significantly(P < 0.05) decreased by 33.6%and 32.5%, respectively, when soil Sb concentration was 21 mg kg-1as compared with the control. The uptake of essential nutrient elements such as Mg, Cu, and Zn by cabbage was obviously affected, while the leaf soluble sugar content slightly changed when the soil Sb concentration exceeded 21 mg kg-1. Based on cabbage physiological responses and soil enzyme activities, the permissible concentration of 21 mg kg-1for Sb in Allitic Udic Ferrisols should be recommended.