Objective To monitor the radioactivity levels in environmental media and food samples in Nanjing City, assess the safety risk levels in environmental and food samples, and promptly identify potential radioactive contamination. Methods The cumulative dose of environmental surface radiation and the gross alpha and gross beta activity concentrations in aerosols, sedimentary dust, drinking water, and food were measured, and the measurement results were statistically analyzed. Results From 2020 to 2024, the gross alpha and gross beta activity concentrations in both source water and treated water in Nanjing City were lower than the national limits for drinking water. The ranges of gross alpha and gross beta activity concentrations in the monitored aerosols were 0.0002-0.0042 Bq/m³ and 0.0001-0.0028 Bq/m³, respectively. The gross α and gross β activity concentrations in sedimentary dust were 0.024-0.244 Bq/m²·d and 0.100-0.716 Bq/m²·d, respectively. There were no significant differences in the annual concentrations of gross alpha and gross beta activity between aerosols and sedimentary dust (P > 0.05). The overall differences in gross alpha and gross beta activity concentrations among samples from different types of food were statistically significant (P < 0.05). Among all samples, the deoxidizer/desiccant had the highest concentrations of gross alpha and gross beta activity. In edible samples, the gross alpha activity concentration of tea was higher than those in other types of food, though all values were within the limits for radioactive substances in food. The gross beta activity concentration in milk powder was higher than those in other types of food. The quarterly environmental surface radiation dose in Nanjing City from 2020 to 2024 ranged from 0.19 to 0.54 mSv. The annual difference in cumulative dose was not statistically significant (P > 0.05). Conclusion The investigation established natural radioactive background data and baseline data in environmental and biological samples in Nanjing City over the past five years. Some samples showed increases in monitoring results. It is recommended to continue monitoring the gross alpha and gross beta activity concentrations and conduct gamma radionuclide testing.

Objective To analyze and master the allocation and distribution of radiological diagnosis and treatment resources in Nanjing, China, and to provide a basis for the health administrative departments to reasonably plan and allocate the radiological diagnosis and treatment resources in the whole city. Methods A general survey using the questionnaire on general information of radiological diagnosis and treatment institutions was conducted to investigate the amount and type of radiological diagnosis and treatment equipment and number of radiation workers in medical institutions in the whole city. Results There were totally 347 radiological diagnosis and treatment institutions at all levels involving 3999 radiation workers and 1342 sets of radiological diagnosis and treatment equipment in Nanjing. In urban radiological diagnosis and treatment institutions, there were 2798 (69.99%) radiation workers and 842 (62.74%) sets of radiological diagnosis and treatment equipment, more than those in the suburbs (1201 and 500 sets). There were 27 (7.78%) tertiary radiological diagnosis and treatment institutions, with 629 (46.87%) sets of radiological diagnosis and treatment equipment, which was more than those in the primary (287), secondary (189), and ungraded (237) medical institutions. There were 158 sets of radiological diagnosis and treatment equipment and 470 radiation workers per million people in Nanjing. Conclusion The distribution of radiological diagnosis and treatment equipment in Nanjing is uneven between urban and suburban areas and between various levels of medical institutions. The government and health administrative departments need to enhance the macroscopic readjustment and control, thus promoting the reasonable allocation of medical resources.

Objective:To grasp the basic information on medical institutions, radiodiagnostic equipments and X-ray diagnosis frequency in Nanjing, in order to provide the health administration department with the basis to rationally allocate medical and health resources.Methods:Using the census method , the work plan was issued in the form of a document by the health administration department, and the radiodiagnostic institutions filled in the relevant questionnaires on the Jiangsu Province Radiological Health Information Management Platform. The frequencies of X-ray diagnosis were obtained by dividing the number of people invloved in X-ray diagnoses by the total number of permanent residents at the end of 2019 in Nanjing.Results:There were 347 radiodiagnostic institutions in Nanjing, including 27 tertiary hospitals, 52 secondary hospitals, 159 primary hospitals and 109 unrated hospitals. There were 3 270 radiation workers and 1 285 X-ray diagnostic equipment of various types in Nanjing, and 69.23% equipment and 44.57% radiation workers are concentrated in tertiary hospitals. Among all types of X-ray diagnostic equipment in the city, DR machines have the largest number (37.59%), followed by dental machines (20.70%). The total number of X-ray diagnosic examinations in the city was 8 563 487, with routine X-ray diagnosis accounting for 55.28%, CT diagnosis for 35.98%. Frequencies was estimated to be 1 007.47 examinations per 1 000 population in medical X-ray diagnosis, of which frequency of routine X-ray diagnosis was 556.90 per 1 000 population, the frequency of CT diagnosis was 362.46 per 1 000 population, the frequency of other diagnoses was 80.03 per 1 000 population, and the frequency of interventional treatment was 8.08 per 1 000 population. X-ray diagnostic examination was mainly concentrated in tertiary hospitals (62.23%), higher in the urban area than that in the suburban area.Conclusions:The basic information on radiation diagnostic institutions and the current status of X-ray diagnostic frequency in Nanjing are initially ascertained. There are obvious deficiencies in the staffing of radiation in the primary and ungraded hospitals, and urban areas were superior to suburbs in medical resources. It is desirable to enhance the macroeconomic regulation of radiodiagnosis and treatment resources in order to protect the health and safety of patients and examinees and reduce the dose to the public.

Objective To obtainthe baseline data of the gross α and gross β radioactivity levels in environmental samples and foods by the monitoring and analyzing the radioactivity levels in drinking water, aerosols and commercial foods in Nanjing City. Methods 15 types of samples, including water source, produced water, aerosol, chicken, pork, stalk vegetable, root vegetable, fresh milk, leafy vegetable, flour, fruits, rice, tea, fish and crab were collected. After pretreatment, LB4008 four-channel low background α and β measuring instrument was used to measure the gross α and gross β radioactivity concentrations. Results The gross α and gross β activity concentrations of source water and produced water in Nanjing from 2016 to 2019 were lower than the national limits. The gross α and gross β activity concentrations in the source water were significantly higher than those of the produced water (P < 0.05). The mean activity concentration range of gross α and gross β in aerosol were 0.16～0.98 mBq/m³ and 0.14～2.15 mBq/m³ from 2016 to 2019, and with no statistical difference in difference samples (P > 0.05). The gross α and gross β activity concentration range of foods were 0.10～17.00 Bq/kg and 22.20～187.20 Bq/kg, of which the gross α and gross β activity concentration in tea were significantly higher than that of other kinds of foods (P < 0.05). Conclusion The radioactivity level in drinking water, atmospheric aerosols and foods in Nanjing were not contaminated by radioactive substances, and the gross α and gross β were relatively stable.