Monitoring and risk assessment of total α and β radioactivity levels in drinking water in the nine districts of metropolitan Chongqing in 2019-2021 / 公共卫生与预防医学

Objective To investigate the radioactivity levels of total α and total β in drinking water in nine districts of Chongqing City from 2019 to 2021, and to provide reference for the risk monitoring of drinking water in the metropolitan areas of Chongqing. Methods The total α and total β radioactivity levels in water samples were determined by the comparative measurement method and the thin source deposit method in GB/T5750.13-2006 “Standard Examination Methods for Drinking Water-Radiological Parameters”. The monitoring results were assessed according to GB5749-2006 “Standards for Drinking Water Quality” and the fourth edition of the WHO Guidelines for Drinking Water Quality. Results From 2019 to 2021, the total α activity concentration of the water samples measured in the nine districts of metropolitan Chongqing ranged from 0.002 to 0.039 Bq /L, and the total β activity concentration ranged from 0.015 to 0.190 Bq /L. There was no significant difference in the activity concentration (tα=0.545, Pα=0.591; tβ=-1.438, Pβ=0.163>0.05). From 2019 to 2021, the average value of total α radioactivity decreased year by year and its activity value was relatively low, indicating a low health risk. However, the average value of total β radioactivity increased year by year, which should be paid attention to. Conclusion The total α and total β radioactivity in water samples measured in the present study are lower than the standard recommended limits. The estimated annual average effective dose of radiation caused by drinking water is 0.005-0.010 mSv, which is lower than the limit of 0.1 mSv recommended by WHO, and this radioactivity level will not have an impact on the health of residents. However, the total β radioactivity level of the monitoring points in Banan and Shapingba is relatively high compared to other jurisdictions, and further tracking and monitoring should be carried out.

Radioactivity level and risk assessment of thorium in surface water in Sichuan Province, China, 2016-2021 / 中国辐射卫生

Objective To investigate the content of thorium (Th) in surface water in Sichuan Province, China, and to evaluate Th-associated health risk via water intake for residents. Methods Twenty-three monitoring sections were set in main surface water bodies in Sichuan Province. From 2016 to 2021, the Th radioactivity level in the water bodies was measured during dry and normal-water seasons. The health risk of residents was evaluated by calculating radioactive Th intake from the surface water bodies combined with the use of a health risk assessment model. Results The Th radioactivity level of the surface water bodies in Sichuan Province was 0.02-0.67 μ./L. There was no significant difference in the Th radioactivity level of different years or different surface water bodies (P > 0.05). A significant difference was observed in the Th radioactivity level of different water seasons (P < 0.05). The total mean annual committed effective doses of Th in all age groups caused by drinking water and water immersion ranged from 3.14 × 10−8 to 8.75 × 10−7 Sv, all lower than the World Health Organization (WHO)-recommended reference level of 0.1 mSv. The overall carcinogenic risks for residents in all age groups ranged from 3.93 × 10−10 to 1.09 × 10−8, all below the most rigorous control limits issued by WHO and International Commission on Radiological Protection. Conclusion The Th-associated health risk via direct water intake and water immersion in main surface water bodies of Sichuan Province is at an acceptable level. Th in main surface water bodies of Sichuan Province is safe for all age groups.

An analysis of the investigation results of radionuclide content in food in Chongqing, China / 中国辐射卫生

Objective To investigate the radionuclide content in food in Chongqing, China by conducting a survey on the radioactivity in food. Methods A total of 114 samples of vegetables, grain, milk powder, and tea were collected in Chongqing. The samples were dried, pulverized into powder, added into Marinelli beakers, and then measured for radionuclides using a high-purity germanium gamma spectrometer (GEM40P4-765). Results The mean activity concentrations of natural radionuclides 238U, 232Th, 226Ra, and 40K in food in Chongqing were (0.396 ± 0.510), (0.199 ± 0.296), (0.140 ± 0.209), and (119.250 ± 105.470) Bq/kg, respectively. The contents of radionuclides in different foods were significantly different (P < 0.05). The mean activity concentration of the artificial radionuclide 137Cs was (0.091 ± 0.308) Bq/kg, and the mean activity concentration of 90Sr measured in nine tea samples was (1.243 ± 0.860) Bq/kg. Conclusion The contents of radionuclides in food in Chongqing are lower than the national standard limits, but the safety of radioactivity in food still needs to be taken seriously, and long-term surveillance of radioactivity in food is needed.

Analysis of gross radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant, 2018-2021 / 中国辐射卫生

Objective To investigate the gross alpha and gross beta radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant before its operation. Methods Ten sampling sites were set up within 30 km of Shidao Bay Nuclear Power Plant. From 2018 to 2021, samples were collected during the dry season and wet season each year and were tested in a laboratory according to Standard examination methods for drinking water—radiological parameters (GB/T 5750.13—2006). Results From 2018 to 2021, the gross alpha radioactivity in drinking water within 30 km of Shidao Bay Nuclear Power Plant was within the range of about 0.004-0.420 Bq/L, which does not exceed the guided gross alpha radioactivity specified in the National Standard; from 2018 to 2021, the gross beta radioactivity level was about 0.008-1.050 Bq/L. In 2018, the gross beta radioactivity at the sampling site 4.7 km from the Nuclear Power Plant exceeded the guided level specified in the National Standards for Drinking Water Quality (GB 5749—2006), but it fell within the guided level in a repeat laboratory test after deducting the effect of 40K on the gross beta radioactivity. Conclusion After deducting the effect of 40K on the gross beta radioactivity, the gross alpha and gross beta radioactivity levels in drinking water within 30 km of Shidao Bay Nuclear Power Plant are within the guided levels specified in the National Standards.

Perfil sociodemográfico e situação de saúde dos pacientes expostos ao Césio 137 em Goiânia / Sociodemographic profile and health situation of patients exposed to Cesium 137 in Goiânia

Este trabalho teve por objetivo analisar os aspectos sociodemográficos e da situação de saúde dos indivíduos expostos ao Césio 137, que constam com cadastro ativo no Sistema de Informação ao Radioacidentado (SISRAD) do Centro de Assistência aos Radioacidentados (CARA). Métodos: Trata-se de um estudo descritivo, com análise transversal, realizado no período de outubro de 2019 a fevereiro de 2020 e que contempla dados registrados desde o ano de 1987. O público-alvo da pesquisa consistiu em indivíduos expostos de forma direta e indireta ao Césio 137 na cidade de Goiânia-Goiás, e que se encontram devidamente cadastrados no CARA. Levou-se em consideração aspectos sociodemográficos, a fim de construir o perfil dos pacientes. Realizado esse processo, procedeu-se à classificação e distribuição dos pacientes, através de critérios como a forma de contato e a dose de exposição. O levantamento de dados foi executado pela análise dos prontuários no SISRAD. Resultados e Conclusões: nos grupos mais jovens não foram identificados cânceres precoces ou malformações nos Grupos NGI e NGII, mas existem relatos que conflitam com as declarações de óbitos dos grupos GI e GII, o que trouxe dificuldades para uma análise estratificada e detalhada. As doenças psíquicas, apresentam maior prevalência, seguidas de causas associadas a hipertensão e a diabetes. Verificou-se a importância da análise de saúde dos radioacidentados como ferramenta de planejamento, preparação e avaliação dos grupos de risco

This study aimed to analyze the sociodemographic aspects and the health situation of individuals exposed to Cesium 137, who have an active record in the Information System for Radio Accidents (SISRAD) of the Assistance Center for Radio Accidents (CARA). Methods: This is a descriptive study, with cross-sectional analysis, carried out from October 2019 to February 2020 and which includes data recorded since 1987. The target audience of the research consisted of individuals exposed directly and indirect exposure to Cesium 137 in the city of Goiânia-Goiás, and who are duly registered with the CARA. Sociodemographic aspects were taken into account in order to build the profile of patients. Once this process was completed, the patients were classified and distributed using criteria such as the form of contact and the dose of exposure. Data collection was carried out by analyzing the medical records in SISRAD. Results and Conclusions: In the younger groups, no early cancers or malformations were identified in Groups NGI and NGII, but there are reports that conflict with the death certificates of groups GI and GII, which brought difficulties for a stratified and detailed analysis. Mental illnesses are more prevalent, followed by causes associated with hypertension and diabetes. The importance of analyzing the health of radio-accidents as a tool for planning, preparing and evaluating risk groups was verified

Cancer mortality in Guarapari, Espiríto Santo State, Brazil, with areas of high natural radioactivity / Mortalidade por câncer em Guarapari, Espírito Santo, Brasil, em áreas de alta radioatividade natural / Mortalidad por cáncer en Guarapari, Espírito Santo, Brasil, en áreas de alta radiactividad natural

Guarapari, a municipality of the state of Espírito Santo, Brazil, reported higher mortality rates for the most common cancers from 1996 to 2000. This municipality has beaches with high natural radioactivity. To verify whether this excessive cancer mortality rate still exist in Guarapari, mortality rates for all causes, cancers, and the most prevalent cancers in this municipality were studied from 2000 to 2018 and compared with those observed in the state. Data on all-cause mortality, all-cancer mortality, and mortality from cancer of the esophagus, stomach, larynx, trachea, bronchi and lung, prostate, breast, and leukemias were collected in Brazilian Health Informatics Department (DATASUS) from 2000 to 2018. Mortality rates were calculated by direct method. Standardized age-adjusted rates (SAAR) were calculated based on standard of the World Health Organization (WHO) world population. Crude mortality rates were calculated for each municipality and SAAR for the state and nine municipalities where natural radioactivity was evaluated. Mortality rates from all causes, all cancers, and different cancers observed in Guarapari did not differ significantly from those observed in the state or municipalities with more than 100,000 inhabitants. Radioactivity levels and mortality rates showed no correlation in nine municipalities where natural radioactivity was known. In conclusion, results showed that mortality from cancer and all causes in Guarapari did not differ from those observed in the state and that there was no correlation between the levels of natural radioactivity and mortality from cancer in areas where natural radioactivity was evaluated.

Taxas de mortalidade maiores para os cânceres mais frequentes foram registradas entre 1996 e 2000 em Guarapari, um município do Espírito Santo, Brasil, onde se localizam praias com alta radioatividade natural. Para verificar a existência desse excesso de mortalidade por câncer em Guarapari, taxas de mortalidade por todas as causas, todos os cânceres e pelos cânceres mais prevalentes no município foram estudadas entre 2000 e 2018 e comparadas com aquelas observadas no estado. Dados de mortalidade por todas as causas, por câncer e por câncer de esôfago, estômago, laringe, traqueia, brônquios e pulmão, próstata, mama e leucemias foram coletados no Departamento de Informática do SUS (DATASUS) de 2000 a 2018. As taxas de mortalidade foram calculadas pelo método direto. As taxas padronizadas ajustadas por idade (TPAI) foram calculadas com base na população mundial padrão da Organização Mundial da Saúde (OMS). Foram calculadas taxas brutas de mortalidade para cada município e as TPAI para o estado e para os nove municípios onde foi avaliada a radioatividade natural. A mortalidade por todas as causas, todos os cânceres e pelos diferentes cânceres investigados em Guarapari não diferiu significativamente daqueles observados no estado ou em municípios com mais de 100 mil habitantes. Não houve correlação entre os níveis de radioatividade e as taxas de mortalidade nos nove municípios onde a radioatividade natural era conhecida. Em conclusão, os resultados mostraram que a mortalidade por câncer e por todas as causas em Guarapari não diferiu daquelas observadas no restante do estado. Além disso, não houve correlação entre os níveis de radioatividade natural e a mortalidade por câncer nas áreas onde a radioatividade natural foi avaliada.

Las mayores tasas de mortalidad por cáncer se registraron entre 1996 y 2000 en Guarapari, un municipio del estado de Espírito Santo, Brasil, donde existen playas con alta radiactividad natural. Para verificar la existencia de mayor mortalidad por cáncer en Guarapari, se estudiaron las tasas de mortalidad por distintas causas, por los tipos de cáncer y por los tipos más prevalentes en este municipio entre 2000 y 2018, y se las compararon con las observadas en todo el estado. Los datos sobre la mortalidad por distintas causas, por cáncer y por cáncer de esófago, estómago, laringe, tráquea, bronquios y pulmón, próstata, mama y leucemias se recogieron del Departamento de Informática de SUS (DATASUS) sobre el periodo de 2000 a 2018. Las tasas de mortalidad se calcularon utilizando el método directo. Las tasas estandarizadas ajustadas por edad (TEAE) se calcularon con base en las de la población mundial estándar de la Organización Mundial de Salud (OMS). Se calcularon las tasas brutas de mortalidad para cada municipio y las TEAE para el estado y para los nueve municipios donde se evaluó la radiactividad natural. La mortalidad por distintas causas, por los tipos de cáncer y por los diferentes tipos de cáncer investigados en Guarapari no difirió significativamente de la observada en el estado o en los municipios con más de 100.000 habitantes. No hubo correlación entre los niveles de radiactividad y las tasas de mortalidad en los nueve municipios donde existe radiactividad natural. Se concluye que la mortalidad por cáncer y por distintas causas en Guarapari no difiere de los resultados observados en todo el estado. Además, no hubo correlación entre los niveles de radiactividad natural y la mortalidad por cáncer en las áreas donde se evaluó la radiactividad natural.

The radioactivity levels of food and the dose in residents due to food intake around Shidaowan Nuclear Power Plant / 中国辐射卫生

Objective To analyze the radionuclide levels in food and the committed effective dose due to food intake in residents around the Shidaowan Nuclear Power Plant (SNPP). Methods Daily food samples were collected within 30 km radius around the nuclear power plant in 2019—2022. The radioactivity levels before and after the operation of SNPP were determined. The data were combined with the dietary consumption of residents in Shandong province, China to estimate the committed effective dose. Results The radionuclides 238U, 232Th, 226Ra, and 40K in food were at normal background levels, and the average radioactivity was (0.062 ± 0.004), (0.121 ± 0.007), (0.162 ± 0.010), and (92.4 ± 5.5) Bq/kg fresh weight. Trace 137Cs and 90Sr were detected in some food samples and the average radioactivity was (0.047 ± 0.003) and (0.193 ± 0.200) Bq/kg fresh weight. The levels of radionuclides did not increase after the operation of SNPP compared with that before operation. The estimated committed effective dose in residents due to food intake was 0.205 mSv. Conclusion The radioactivity of food in the area around SNPP shows no difference before and after operation, and the dose burden is low in local residents.

Response of radioactivity meter in vertical direction of ionization chamber / 中国辐射卫生

Objective To determine the responses of radioactivity meter at different positions in the vertical direction of the ionization chamber by measuring different radioactive sources. Methods The radiation of cesium-137, cobalt-60, and americium-241 nuclides was measured at different positions in the vertical direction of the ionization chamber with commonly used clinical radioactivity meters. The measured values were fitted to obtain three trend lines. The maximum deviation of the measured values was estimated according to the trend line, and the deviation was estimated at different syringe needle heights. Results According to the trend lines, the maximum deviation of the radioactivity meter CRC-55tR in measuring cesium-137, cobalt-60, and americium-241 nuclides was 5.15%, 5.98%, and 6.25% respectively. The radioactivity meter RM-905a was used to measure three nuclides at different syringe needle heights, and the maximum deviations were −4.33%, −9.9%, and −12.65%, respectively. Conclusion The three nuclides showed different change patterns in measurement with CRC-55tR and RM-905a but similar change patterns in measurement with the same radioactivity meter. The values measured with the same radioactivity meter showed significant deviations at different positions in the vertical direction of the ionization chamber. It is recommended to make position correction for commonly used nuclides. Reducing measurement error and improving measurement accuracy of nuclides are of great significance for radiation protection.

Exploring occupational hazards and protective strategies in power generation enterprises / 中国职业医学

Currently, power generation in China is dominated by thermal power, wind power, nuclear power, and hydropower enterprises. The power source mainly comes from thermal power generation. The occupational hazards in thermal power station are noise, high temperature, power frequency electric fields, dust, and chemical toxins and so on, with noise and dust (silica and coal dust) being the primary factors. The occupational hazards in wind power station are noise, power frequency electric fields, high temperature, low temperature, and chemical toxins (sulfur hexafluoride, toluene, styrene, etc.), with noise and power frequency electric fields being the major concerns. The occupational radiation hazards in nuclear power station are gamma rays, beta rays, X-rays, neutrons, alpha rays, and radioactive aerosols. There is special attention in radiation protection but not enough protection in non-radioactive hazards such as noise, high temperature, and ammonia. The occupational hazards in hydropower station are noise, power frequency electric fields, vibration, radon and its de-composites, and chemical toxins, with noise and power frequency electric fields being the primary hazards. Different categories of power generation enterprises should identify key hazards and work site for occupational disease prevention and control based on the features of occupational hazards. Improving occupational health management and protection levels are essential measures.

Monitoring and analysis of radioactivity levels in drinking water sources in five cities of Sichuan province from 2016 to 2020 / 中华放射医学与防护杂志

Objective:To understand the radioactivity levels of water source in five key cities of Chengdu, Yibin, Mianyang, Guangyuan, Leshan in Sichuan province, and evaluate the radiation safety of these water sources.Methods:From 2016 to 2020, the measuring site selection, sampling and analysis were made for measuring the radioactivity levels of total alpha, total beta, 90Sr, 137Cs, 226Ra, U, Th in drinking water sources in these five cities. Reference was made, respectively, to the national standards Determination of total α radioactivity concentration in water thick source method (EJ/T 1075-1998), Determination of total β radioactivity in water evaporation method (EJ/T 900-1994), Radiochemical analysis method of strontium-90 in water and biological samples ash (HJ 815-2016), radiochemical analysis of cesium-137 in the ash of water and biological samples (HJ 816-2016), Analysis and determination of radium-226 in water (GB 11214-1989), Analysis of trace uranium in environmental samples -3 laser fluorescence law (HJ 840-2017), and Food safety in the test of radioactive substances in food determination of natural thorium and uranium (GB 14883.7-2016). Results:The activity concentration ranges from 0.011 to 0.076 Bq/L for total alpha, 0.027 to 0.098 Bq/L for total beta, 0.21 to 0.45 mBq/L for 137Cs, 1.0 to 2.4 mBq/L for 90Sr, 6.1 to 16.0 mBq/L for 226Ra, 0.06 to 0.21 μg/L for Th, and 0.73 to 3.30 μg/L for U. There were no significant differences in the concentrations of total alpha, total beta, 90Sr, 137Cs, 226Ra, U and Th in different water sources and different years ( P>0.05). There were no significant differences in the concentrations of total alpha, total beta, 90Sr, 137Cs and 226Ra during different water periods ( P>0.05). There were statistical differences in U activity concentration in different water periods ( H=16.53, P<0.05), and statistical differences in Th activity concentration in different water periods ( H=15.61, P<0.05). Conclusions:The survey showed that the total alpha, total beta, 90Sr, 137Cs, 226Ra, U and Th radioactivity levels in drinking water sources in Chengdu, Yibin, Mianyang, Guangyuan and Leshan of Sichuan province were at the same level as the relevant data in the Natural environmental radioactivity level in China published by the State Environmental Protection Bureau in 1995. All of there values were within the data range released by the 2013-2021 National Radiation Environment Monitoring Quality Report issued by the Radiation Environment Monitoring Technology Center of the Ministry of Ecology and Environment. The radioactivity level in water sources in the five key cities was at a safe level.

Investigation of 131I radioactivity levels in soil around the nuclear medicine decay pool after the 7·20 extraordinary rainstorm disaster in Zhengzhou, Henan / 中华放射医学与防护杂志

Objective:To explore whether or not radioactive wastewater leakage or overflow exists in the nuclear medicine decay pool after the 7·20 extraordinary rainstorm disaster and to analyze its causes, so as to provide scientific basis for the design, construction and maintenance of the nuclear medicine decay pool and the radiation protection management of nuclear medicine in the future.Methods:Three hospitals A, B and C where 131I therapy are being performed were selected in Zhengzhou city, Henan province. Sampling points were set based on the monitoring result of the environmental radiation level around the nuclear medical decay pool in line with the relevent standard method. Soil samples were collected at different depths. The 131I radioactivity level in the soil was measured using HPGe gamma spectrometer, with the measured result being processed and analyzed. Results:Except for Hospital B where no 131I was detected, different 131I activity concentrations were detected in the soil samples collected around the nuclear medicine decay pool at Hospitals A and C. The 131I activity concentrations ranged from 16.4 to 98 111.8 Bq/kg at Hospital A and from 10.6 to 7 176.6 Bq/kg at Hospital C. After a time period of decay, the repeated detection has shown that the 131I activity concentrations ranged from 1.3 to 17.0 Bq/kg at Hospital A and from 3.9 to 7.1 Bq/kg at Hospital C. The 131I activity concentration in the soil at the depth of 0-5 cm was higher than that at the depth of 5-10 cm soil at the same sampling point. The ratios of activity concentration of 131I between different depths ranged from 1.3 to 13.1, with the median value of 5.9. Conclusions:After the 7·20 extraordinary rainstorm disaster, the surrounding environment of nuclear medicine decay pools at a few hospitals was contamminated by 131I to some extent. To prevent the risk of leakage of radioactive wastewater, the safety evaluation and management of radiation protection should be made better with increased awareness during the design, evaluation, construction and use of nuclear medicine decay pools.

Survey of total radioactivity in drinking well water around Bayanwula uranium mine / 中华放射医学与防护杂志

Objective:To investigate the total radioactivity in drinking well water around the Bayanwula uranium mine.Methods:Totally 174 samples of drinking well water and 5 samples of filtered well water from residential houses were collected during dry and wet seasons in 2020 around the Bayanwula uranium mine. Total α and total β radioactivity in dry season and wet season were analyzed for detrmining whether there were differences between them and the relation between total radioactivity with different locations away from the uranium center. The radioactivity in filtered drinking well water used in residential houses was also investigated. Radioactivity were measured and analyzed using low background alpha and beta radioactivity meters, and the data were analysed using SPSS analytical statistical method.Results:In the drinking well water around Bayanwula uranium mine, the activity concentrations of total α and β measured in dry season were 0.024-2.468 Bq/L with a mean of (0.605±0.507) Bq/L and 0.125-1.395 Bq/L with a mean of (0.420±0.235) Bq/L, respectively. The values measured in wet season were 0.049-2.988 Bq/L with a mean of (0.825±0.605) Bq/L for total α and 0.059-1.623 Bq/L with a mean of (0.506±0.265) Bq/L for total β, respectively. The average value of total radioactivity in water samples was lower within 10, 30 and 20 km of the uranium mine in the descending order.Conclusions:The radioactivity in well water around the Bayanwula uranium mine is high, with the total α and β in samples greater in wet season than in the dry season and without elevated levels as compared to the pre-mining background.

Measurement and analysis of 90Y radioactivity in urine of patients treated with 90Y resin microspheres / 中华放射医学与防护杂志

Objective:To evaluate 90Y activity concentration in renal excretions during the first 48 hours after being treated with 90Y resin microspheres seleceive internal radiation therapy(SIRI) and to provide advice on the management of patient excreta after surgery. Methods:After surgery, urine excreted from 3 patients during 0-24 h and 24-48 h was collected respectively, and the 90Y activity concentration in urine was tested and analyzed. Results:90Y radioctivity in the urine excreted from 3 patients after surgery was (1 266±258)kBq/GBq during 0-24 h and (140±106) kBq/GBq during 24-48 h, respectively, and 90Y activity concentration were (640±113) kBq/L during 0-24 h and (53±12) kBq/L during 24-48 h. Conclusions:90Y radioactivity in patient′s urine excreted at 1 d was about 10 times higher than that at 2 d. After surgery, patients can accelerate the reduction of free 90Y activity by increasing excretion. Urine excreted by the patients during hospitalization should be handled in accordance with the requirements of the national standard HJ 1188-2021 Radiation protection and safety requirements for nuclear medicine.

Impact of water supply from Qiandao Lake on gross radioactivity level in drinking water in downtown Hangzhou / 中华放射医学与防护杂志

Objective:To investigate the levels of gross radioactivity in drinking water in Hangzhou city before and after Qiandao Lake as the water source to the main urban area of Hangzhou.Methods:Since 2012, water samples were collected from water source, factory water and peripheral water in rainy and dry seasons, respectively, to determine their gross α and β activity concentrations for comparison and analysis.Results:The gross radioactivity levels in drinking water in Hangzhou are lower than the limits specified in the national standard "Standards for drinking water quality" (GB 5749-2006), without statistically significant difference for these water sources between the rainy and dry season ( P>0.05). The gross α(0.008±0.000)and gross β(0.034±0.013)levels in Qiandao lake were both less than those in Qiantang river ( Z=-3.235, -4.058, P<0.05), with significant difference ( Z=-2.181, -4.577, P<0.05). There was no significant difference in gross α and gross β in factory water and peripheral water before and after the operation of Qiandao Lake water supply project ( P>0.05). Conclusions:The gross radioactivity in drinking water in downtown Hangzhou are low from 2012 to 2020. The gross radioactivity levels in Qiandao Lake are lower than in the lower reaches of Qiantang river and Dongtiao steam. No impact was generated on radioactivity levels in drinking water after Qiandao lake supplied water to Hangzhou.

Monitoring and evaluation of radioactivity levels in water sources in Beijing, China, 2012—2021 / 中国辐射卫生

Objective To investigate and evaluate the changes in total α and total β radioactivity levels in drinking water in Beijing, China, 2012—2021. Methods The test results of total α and total β radioactivity levels at 14 monitoring sites from 9 groundwater sources and 5 surface water sources in Beijing, 2012—2021 were collected. The radioactivity levels in the two types of water sources were compared. Statistical charts were used to show the monitoring situation at sampling sites in different regions during different periods, and related issues were explored. Results The total α and total β activity concentrations measured at monitoring sites from some water sources in Beijing, 2012—2021, were less than the total α and total β guideline values specified in the Standards for Drinking Water Quality (GB 5749—2006) (total α: 0.5 Bq/L, total β: 1.0 Bq/L). The mean total α activity concentration in the groundwater was significantly higher than that in the surface water. The total α and total β radioactivity levels in the reservoir D in the surface water were slightly higher than those in the other surface water. Conclusion In the past decade from 2012 to 2021, the total α and total β radioactivity levels in some water sources in Beijing were generally in a good condition and fluctuated within the range of environmental background values, without significant changes on the whole.

Analysis of radionuclide content in the surface soil of Panjin, China / 中国辐射卫生

@#<b>Objective</b> To measure the specificactivity of natural and synthetic radionuclides in the environmental soil of Panjin, China and determine the content of radionuclides in the surface soil, and to conduct a scientific assessment of the radiation health risks of residents in this area. <b>Methods</b> Thirty-one surface soil samples were collected within the jurisdiction of Panjin, and a high-purity germanium detector was used for γ spectrum analysis to obtain the content of radionuclides and the current environmental radioactivity level. The two independent samples mean <i>t</i>-test was used to compare the specific activity data of radionuclides in soil samples between Panjin and Liaoning Province or China. <b>Results</b> The meanspecific activities of natural radionuclides ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, and synthetic radionuclide ¹³⁷Cs in the surface soil samples of Panjin were 18.7 Bq/kg, 19.6 Bq/kg, 23.5 Bq/kg, 604.6 Bq/kg, and 0.9 Bq/kg, respectively. <b>Conclusion</b> The specific activities of natural and synthetic radionuclides in the surface soil samples of Panjin Area at the background level, causing a very low health risk to the people in this area.

Gross α and gross β radioactivity of environmental samples in Wuxi, China, 2014—2019 / 中国辐射卫生

Objective To study gross α and gross β radioactivity in environmental samples in Wuxi, China, and perfect the radioactivity data, and to discover possible radioactive contamination in time. Methods The BH1227 low-background α and β measuring instrument was used to determine gross α and gross β radioactivity in sedimentary dust, aerosol, drinking water, and food samples in Wuxi. Results Among environmental samples collected in Wuxi, 2014—2019, the mean gross α and gross β radioactivity levels were 0.01～5.98 Bq/kg and 9.47～547.86 Bq/kg in food samples, respectively, 1.2～22 mBq/L and 0.1～141 mBq/L in water samples, respectively, 39～44790 mBq/m3 and 743.1～101500 mBq/m3 in sedimentary dust samples, respectively, and 50～1125 μBq/m3 and 38～9510 μBq/m3 in aerosol samples, respectively. Conclusion We should strengthen radioactivity monitoring of environmental samples in Wuxi through increasing the scope and frequency of monitoring, to perfect baseline radioactivity data of Wuxi.

Discovery and discussion of 7Be and another full-energy peak in water from 3D water phantom of a proton therapy system / 中国辐射卫生

Objective To discuss 7Be and a 77.2 keV full-energy peak with short half-life found in the water sample from the 3D water phantom of a proton therapy system. Methods We measured the water sample from the 3D water phantom of a proton therapy system according to Determination of Radionuclides in Water by Gamma Spectrometry (GB/T 16140—2018). Results The activity concentration of 7Be in the water sample was 1.30 × 101 Bq·L−1 on December 24, 2018; 4.3 × 101 Bq·L−1 on March 22, 2019; and 1.41 × 101 Bq·L−1 at the time of sampling on December 19, 2018. On December 24, 2018, the net peak area of the 77.2 keV full-energy peak in the sample was 683 ± 45, and the measurement time was 26123.02 s; on March 22, 2019, the net peak area decreased to the background level of 194 ± 49, and the measurement time was 86400.00 s. Conclusion In the 3D water phantom of the proton therapy system, 7Be can be generated from the spallation reaction between high-energy neutrons and oxygen in water. In addition, we find a full-energy peak at 77.2 keV with short half-life. The activity concentration of 7Be in the water sample is lower than the exemption level, but the activity concentration at sampling may not be the maximum activity concentration in the process of quality control. The inductive radionuclide 7Be produced in the 3D water phantom should be identified and properly evaluated in the assessment of occupational radiation hazards of proton therapy system.

Evaluation and design of volume of intermittent decay pool for nuclear medical radioactive waste water / 中华放射医学与防护杂志

Objective:To provide the calculation method for evaluating and designing the volume of nuclear medicine intermittent decay pool, so as to provide technical reference for medical institutions, environmental impact assessment institutions and management departments, etc.Methods:By constructing a mathematical model and deriving the calculation formula, the relationship between the volume of intermittent decay pool and the radioactivity level of wastewater was established.Results:There were differences in the number of diagnosis and treatment of patients, the amount of nuclide used and the amount of waste water produced in the nuclear medicine department at different medical institutions, so the evaluation and design of the intermittent decay pool were also different as a result . But the result should meet the relevant requirements of the standards GB 18871-2002 and HJ 1188-2021: the total activity discharged every month ≤10 ALImin, and the activity discharged once≤1 ALImin; gross alpha activity ≤1 Bq/L, gross β activity ≤10 Bq/L, 131I activity concentration ≤10 Bq/L; the temporary storage time after filled with radioactive wastewater ≥10 times longest half-life, and the temporary storage time of 131I in patient waste water ≥180 d. Conclusions:The calculation method provided in this paper can be used to evaluate and design the volume of intermittent decay pool in nuclear medicine departments.

Determination of gross α and ß radioactivity of drinking water in a district in Shanghai / 上海预防医学

ObjectiveTo investigate the radioactive level of gross alpha and beta in drinking water in one district in Shanghai and provide a scientific basis for measuring the level of radiation in case of drinking water pollution due to potential nuclear accidents. MethodsA total of154 samples collected across the district were monitored by using the standard examination method for drinking water - radiological parameters GB/T 5750.13-2006. ResultsAll the samples of the drinking water conformed to the standard for drinking water quality GB 5749-2006. The differences between different seasons were significant. The difference of gross alpha and beta radioactivity of drinking water was significant between the high water period and the dry water period. The former was higher than the latter. ConclusionIt is very important to monitor and study radioactivity of drinking water regularly for the prevention and control of health damage caused by radioactive water pollution.