Aim To explore the toxicity and safety of five kinds of known positive drugs, cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexa-methasone acetate and azacitidine, using zebrafish em-bryos. Methods We selected normally developed 4 hpf zygote, and used water bath infecting method to add the drug to the artificial seawater. Each drug had five concentrating groups, a separate control group and solvent control group. We observed the dead zebrafish embryos after 120 hpf drugs, counted the number of deaths and deformities of zebrafish embryos, and cal-culated mortality abnormal rate, the median lethal con-centration (LC50 ), concentration for 50% of maximal effect (EC50 ), therapeutic index (TI) under 120 hpf condition. We also used the formula TI = LC50 / EC50 to calculate positive drug therapeutic index. Based on measured LC50 we calculated most nonlethal concentra-tion (MNLC) of each drug setting, namely 1 / 10 MN-LC, 1 / 3 MNLC, MNLC,LC10 four concentration, tha-lidomide as a positive control, vitamin C as a negative control, artificial seawater as control, 0. 5% DMSO as solvent control. Put in 28. 5 ℃ environment for 120 hours,embryo development was observed daily for de-velopmental state,mortality,deforming rate and abnor-mal condition. Results The result of five drugs LC50 in descending order: cyclophosphamide > azacitidine> tetracycline hydrochloride > acetylsalicylic acid >dexamethasone acetate. EC50 in descending order: cy-clophosphamide > tetracycline hydrochloride > azaciti-dine > acetylsalicylic acid > dexamethasone acetate. The TI values of cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexamethasone ace-tate, azacitidine were 1. 92, 1. 11, 1. 05, 1. 44, 2. 99, respectively. Conclusion Zebrafish embryo model can be used in the preliminary evaluation of drugs, and the study of early developmental toxicity and safety.

Objective To explore the current status of radiation protection in interventional procedure and to analyze the existent problems.Methods Using the random sampling,70 interventional radiology workplaces were selected from Hangzhou,Ningbo,Wenzhou,Shaoxing and Jinhua.Information on personal radiation protective products and equipment was collected by filling out the form by hospital and the radiation dose was monitored at various body parts of the workers and at the outside of the operating room.Results All hospitals have been equipped with personal radiation protective products and equipment,22 of which were not with these products and equipment as required.Chest,abdomen and lower limb of interventional radiology workers are easy to receive higher radiation dose than in head (F =4.85,4.92,P ＜ 0.05).The acceptance rates among different body parts of the workers were difference significantly (x2 =35.14,14.92,P ＜ 0.05).Using protective curtain can reduce the radiation dose significantly (t =11.61-68.28,P ＜ 0.05).Meanwhile,it also can improve the acceptance rates significantly (x2 =6.09-28.45,P ＜ 0.05).Conclusions It is necessary to strengthen the use of radiation protection equipment among interventional radiology workers to reduce the levels of the individual doses to them.Hospitals must enhance the routine monitoring for improved radiaton protection.

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 establish a rapid,high-efficiency and clean way to monitor and pretreat the radioactivity in foods.Methods Food samples,20 kg each of cabbage,crucian,shrimp,pork and 20 L of milk,were collected around Qinshan nuclear power plant,totaling 10 samples for each food.Each type of foods was arranged in two groups each with 10 samples.Samples were pretreated using traditional ashing method (TAM) and microwave ashing method (WAM) separately.HDEHP were used for 90Sr separation and measurement.Calculations were made for the time spent on food pretreatment.The ash-fresh ratio and the recovery rate of 90Sr by the two different method were calculated,with the quality of ash being evaluated.Results The mean time spent on pretreatment was cabbage 20 h,crucian 54 h,shrimp 46 h,pork 58 h and milk 74 h for TAM group,and cabbage 8.5 h,crucian 26 h,shrimp 23 h,pork 26 h and milk 30 h for WAM group,respectively.The time spent by WAM was half the time less than by TAM,especially for animal edible product.The ash-fresh ratios from WAM group were higher than from TAM group.The recovery rates of 90Sr from WAM group in the analytical process were all above 75％,higher than from TAM group.Ashes produced by WAM were hoary,uniform,carbon residue-free and fully ashed.Conclusions WAM pretreatment can pretreat food rapidly,efficiently,cleanly with less loss and better ashing effect.These can meet the requirement of rapid pretreatment of radioactivity in food.

Objective:To investigate the levels of gross radioactivity in drinking water and of 90Sr in food around Sanmen nuclear power plant (NPP) before and after operation. Methods:From 2012 to 2019, 7 drinking water monitoring sites were selected around the Sanmen NPP to collect source water, factory water and peripheral water, respectively, in order to measure and analyze the total radioactivity level in drinking water. Based on the dietary habits of local residents, 4 kinds of food such as grains, vegetables, freshwater fish and marine fish grown locally were sampled to measure and analyze the activity concentration of 90Sr. Results:Before the operation of Sanmen NPP, the total α radioactivity and total β radioactivity in drinking water around the NPP were 0.001-0.063 Bq/L and 0.019-0.210 Bq/L, respectively. After operation, the total α radioactivity and total β radioactivity were 0.001-0.084 Bq/L and 0.025-0.079 Bq/L, respectively. Both were lower than the national standard value given in the GB 5749-2006 " Sanitary standards for drinking water" . There was no significant change in the radioactivity level of source water, factory water and peripheral water during the wet and dry periods. The activity concentration of 90Sr in these four types of food ranged from 0.037 to 1.216 Bq/kg before operation and from 0.049 to 0.692 Bq/kg after operation, all lower than the standard value of " Standard for the concentration in radioactive substances in food" (GB 14882-94). Conclusions:Before and after the operation of Sanmen NPP, the total α and total β radioactivity in drinking water and 90Sr activity concentration in food are stable, below the national standard limit.

Objective To observe the changes of circadian characteristics and stress-response-related physiological parameters including respiration, blood pressure, electrocardiography and body temperature of conscious rhesus monkeys by implantable telemetry technique. Methods Surgery was performed on 8 rhesus monkeys (half male and half female, 3-5 years old) for implantation of a telemetry transmitter. After 3 weeks of recovery, the physiological parameters of respiration, blood pressure, electrocardiography and body temperature of the conscious rhesus monkeys without binding were automatically recorded by a DSI telemetry system and the data were analyzed by the Ponemah software. Results Some electrocardiographic indexes showed significant differences at daytime and nighttime (P＜ 0. 05 or P＜ 0. 01) including mean heart rate (HR) ( 155. 0-122. 4 times/min), respiratory rate interval (RR-I) (410. 8-535. 7 ms), T-wave amplitude (T-A) (0. 181-0. 157 mV), PR interval (PR-I) (80. 4-87. 4 ms), QT interval (QT-I) (224. 8-263. 9 ms), and corrected QTcb interval (QTcb) (352. 3-366. 7 ms). The indexes of blood pressure and respiration at daytime were significantly higher than those at nighttime (P＜ 0. 01), including the mean systolic pressure (SYS) at daytime and nighttime (144. 6-131. 6 mmHg), diastolic pressure (DIA) (99. 8- 89. 9 mmHg), mean arterial pressure (MAP) (121. 5-110. 2 mmHg), tidal volume (TV) (64. 5-36. 6 mL), minute ventilation (MV) (1931. 9-920. 1 mL/min), and respiratory rate (RR) (32. 3-25. 4 times/min). Cleaning and feeding activities of the laboratory staff at 9: 00 a.m. and 2: 00 p.m. had a certain effect on the stress-responses in the monkeys. Conclusions The parameters of respiration, blood pressure, electrocardiography and body temperature of the conscious rhesus macaques observed by implanted telemetry system show obvious circadian changes, which can truly reflect the changes of physiological indexes at daytime and nighttime, and avoid the stress in hungry monkeys caused by the feeding and cleaning activities of laboratory staff. This technique can improve the efficiency of drug safety pharmacology studies, reduce the number of animals used and meet the requirements of 3R principles.

Objective:To investigate and analyze the radioactivity level of 90Sr in offshore seawater and seafood therein around Sanmen nuclear power plant (NPP) and to estimate the annual committed effective dose to local population from ingestion of 90Sr in seafood from 2015 to 2019. Methods:From 2015 to 2019, the offshore seawater and 3 kinds of marine products grown locally in Sanmen and consumed by local residents were collected for measurement of the level of 90Sr radioactivity. The committed effective doses to the local population were estimated based on monitoring result and consumption data on seafood in Zhejiang offshore. Results:The radioactivity concentrations of 90Sr ranged from 2.4 to 4.1 mBq/L in the seawater, close to the natural radioacrive background level and from 6.7×10 -2 to 1.3 Bq/kg in seafood, lower than the standard values specified in the "Limited concentrations of radioactive materials in foods" (GB 14882-94). Annual committed effective dose to the local population from 90Sr attributable to consumption of seafood in Sanmen County from 2015 to 2019 were 2.2×10 -4-4.2×10 -4mSv, respectively, far lower than the worldwide committed effective dose result ing from internal exposure. Conclusions:From 2015 to 2019, the radioactivity concentration of 90Sr in seawater and seafood are stable, with neglectable dose burden to the local population.

Objective:To investigate and analyze the radioactivity levels of 90Sr and 137Cs in drinking water and 137Cs in food after the installation of the first AP1000 nuclear power unit in China. Methods:From 2012 to 2019, four drinking water monitoring points around AP1000 nuclear power unit located at Sanmen nuclear power plant site were collected during the wet season and dry season, 90Sr and 137Cs and radioactivity concentrations were determined in drinking water. Local rice, cabbage, crucian and mullet were collected to determine the radioactivity concentration of 137Cs. Results:From 2012 to 2019, the radioactivity concentrations of 90Sr and 137Cs in drinking water were 1.2-9.8 mBq/L and 0.2-8.1 mBq/L, respectively. The radioactivity concentration of 137Cs in food were 1.1×10 -2-2.8×10 -1 Bq/kg, lower than the limits specified in the Limited concentrations of radioactive materials in foods (GB 14882-94). Conclusions:After the installation of the first AP1000 nuclear power unit in China, the radioactivity levels of 90Sr and 137Cs in drinking water and 137Cs in foods are stable, without environmental impact identified.