Objective: To investigate the current status of screen exposure among preschool children in Shanghai and its association with family screen environment, so as to provide a scientific basis for family screen management. Methods: Using a convenient sampling method, a total of 349 preschool children aged 4-6 years were selected from 36 kindergarten classes in Xuhui District and Pudong New Area in Shanghai during April to June in 2023. Demographic characteristics and family screen environment were surveyed through an online questionnaire. Screen exposure of children was assessed using a diary method, with parents recording the activities over a 7day period. Multiple Logistic regression analysis was employed to identify factors influencing childrens screen content. Results: The average daily screen exposure time for children was (61.2±40.2) minutes, with an average of (12.4±17.6) minutes spent on educational screen content, 80.8% predominantly watched noneducational screen content. The percentages of time spent on educational screen content for 4yearold boys, 4yearold girls, 5yearold boys, 5yearold girls, 6yearold boys, and 6yearold girls were 20.1%, 14.7%, 21.3%, 21.9%, 20.6%, and 26.9%, respectively. Multivariate Logistic regression showed that children aged 5yearold (OR=0.49, 95%CI=0.25-0.96) and 6yearold (OR=0.45, 95%CI=0.21-0.95) were negatively associated with more noneducational screen content (P<0.05). However, occasional (OR=2.02, 95%CI=1.09-3.75) and sometimes (OR=4.50, 95%CI=1.70-11.90) using electronic devices to calm young child when crying, as well as children using electronic devices without adult supervision (OR=1.81, 95%CI=1.01-3.24) were positively associated with more noneducational screen content (P<0.05). Conclusions Preschool children in Shanghai exhibit high exposure to noneducational screen content, and family screen environment and parentchild interaction are associated with noneducational screen exposure. Strategies for family screen management should be developed to regulate childrens screen exposure behaviors, allowing electronic devices to play a positive role in their developmental process.

Objective To acquire the basic information on diagnostic radiology and radiotherapy institutions and the frequency of medical radiation of Hebei province in 2016.Methods A survey was made using questionnaires for basic information on medical X-ray diagnosis,interventional radiology,radiotherapy and clinical nuclear medicine.Values of frequencies were derived for each type of medical X-ray procedure by dividing the total population.Results In 2016 there were 2 951 institutions at province level and 6 966 pieces of equipment involved in diagnostic radiology and radiotherapy treatments.Frequency values were estimated to be 379.25 examinations per 1 000 population in medical X-ay diagnosis,2.31 per 1 000 in interventional radiology,0.55 per 1 000 in radiotherapy and 1.65 per 1 000 in clinical nuclear medicine.The frequency for CT examination was 136.39 per 1 000,accounting for 36％ of the total frequencies in the province,with average annual growth rate of 12.4％.The highest value of frequency in clinical nuclear medicine was from Shijiazhuang among all types of medical procedures in different regions,11 times higher than the lowest value found in Hengshui city.Although the number of tertiary hospitals only accounted for 2.3％ of the total number of institutions,they contributed 25.5％,by examination number,of the medical X-ray diagnosis and 35.3％ of the CT examination.Interventional radiology and radiotherapy contributed more than 70％ of the total frequencies in the province,and clinical nuclear medicine was as high as 97.7％.Conclusions The basic information on diagnostic radiology and radiotherapy institutions and the frequency of medical procedures in Hebei in 2016 have been preliminarily made clear.Medical exposure could maintain a long-term growth trend.The frequency distribution of medical procedures in various regions and medical institutions is highly unbalanced.It is desirable to enhance the macroeconomic regulation and the management of medical radiation protection in order to rationally perform all types of diagnostic radiology and radiotherapy treatments to protect the health and safety of the patients and the examined individuals,and to promote the sustainable development of the health care services.

Objective: To analyze the clinical characteristics and imaging features of occupational pulmonary thesaurosis induced by dust of iron and its compounds (OPTIDIC). Methods: A total of 230 cases of occupational welder's pneumoconiosis (OWP) patients or observation subjects were selected as the research subjects using the retrospective analysis method. They were diagnosed in four occupational disease diagnosis institutions in Shandong Province from 2010 to 2017. The high kV X-ray chest radiography or chest digital radiograph (hereinafter referred to as X-ray) were re-read to screen OPTIDIC patients. The clinical data of OPTIDIC patients were collected and analyzed. Results: Among the 230 cases, 56 cases were diagnosed as OPTIDIC, accounting for 24.3%. The clinical symptoms of the 56 patients with OPTIDIC were cough, sputum, chest tightness, shortness of breath, and difficulty breathing, while their physical signs were low or coarse breath sounds in lungs and others. Most of the X-ray results showed p shadows or q shadows, accounted for 98.2%, of which p/p shadow and q/q shadow accounted for 62.5%. The result of chest computed tomography (CT) showed diffuse point/round shadow and diffuse glass shadow in OPTIDIC patients. The result of fibro-bronchoscopy showed that a large amount of iron lutein particles was accumulated in macrophages and biopsy of lung showed idiopathic pulmonary hemosiderosis in OPTIDIC patients. Conclusion: The clinical characteristics of OPTIDIC patients showed no different from OWP. However, the result of X-ray of OPTIDIC patients mainly showed small circular shadows, and their CT images mainly showed diffuse point/round shadows or grinding glass shadow, which could be used to the differential diagnosis of OPTIDIC and OWP.

Objective To investigate the number, distribution, and types of radiation of non-medical radiation institutions in Hebei Province, China, and to explore the current radiation protection in the employing units and occupational health management of radiation workers in 2022. Methods A questionnaire survey was conducted in the non-medical institutions engaged in nuclear technology application in Hebei Province, and different types of employing units were selected to monitor the radioactivity level in the workplace. Results A total of 681 non-medical institutions engaged in radiation technology application completed the survey, covering all cities with subordinate districts in the province, including 1605 radioactive devices, 2960 active devices, 45 non-uranium metal mines, and 14 non-sealed workplaces. A total of 8617 radiation workers were surveyed, with a personal dose monitoring rate of 70.9%, a radiation protection training rate of 61.1%, and an occupational health examination rate for radiation workers of 59.3%. A total of 614 radiation protection monitoring instruments were provided, with a personal protective equipment allocation rate of 51.1% and a personal dose alarm device allocation rate of 51.8%. The radiation occupational hazardous factor testing was completed for 54 workplaces, and the results were all qualified. Conclusion There are still significant deficiencies in personal dose monitoring in the radiation work units in non-medical institutions and occupational health examination in the radiation work units in our province. The health administrative departments should strengthen health supervision and law enforcement, enhance radiation protection and skill training for employers, and more effectively control the impact of radiation hazards on personnel health.

Objective: To investigate the incidence of contact dermatitis among workers in cemented carbide production enterprises. Methods: From October 1997 to October 2017, an occupational epidemiological survey was conducted on a large-scale cemented carbide production enterprise, and occupational health examinations were conducted for employees. 152 people were exposed to hard metal dust (hard metal raw material dust and alloy dust) . The employees in the work group were contact groups, and 142 employees in the non-dusting operation of the company were in the control group. A detailed retrospective survey of hard metal production workers with contact dermatitis history in the two groups was conducted to analyze the risk factors of contact dermatitis exposure to hard metal dust. Results: The incidence of allergic diseases in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ²=23.793, P<0.05) . The incidence of contact dermatitis in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ²=24.659, P<0.05) ; the changes of contact dermatitis in the contact group were mainly allergic contact dermatitis, and some showed irritative contact dermatitis; the operator had respiratory symptoms (including work-related nasal congestion, cough, wheezing) , difficulty breathing may be the influencing factors of contact dermatitis (RR=2.60, 95%CI: 1.10-6.20, P<0.05) . Conclusion Hard metal alloy enterprises are exposed to hard metal dust. The incidence of contact dermatitis is high in workers, and the occurrence of contact dermatitis may be associated with those with respiratory symptoms.