OBJECTIVETo calculate the consequence of acute ammonia poisoning accident which was caused by the leak of liquefied ammonia storage tank, so as to provide theoretical basis for working out the counterplan of accidents.

METHODThe amount of liquefied ammonia to be reserved, the pressure and temperature inside the tank were inputted; based on the physical chemistry principle, the evaporating amount was calculated; and using the proper diffusion model, the size of ammonia cloud, percentages of death and depth range of the poisonous gas etc was calculated.

RESULTSAssuming the leaky tank had liquefied ammonia 50 t, the pressure and the temperature were 2.5 MPa and 30 degrees C respectively, the evaporating amount and the size of ammonia cloud were calculated. The radiuses, of the ammonia released cloud of severe, moderate and mild hazard were 108 m, 216 m, 370 m respectively; if the exposured time was 30 min, the percentage of death would be 50%; if the exposured time was 5 min, the percentage would be 10%; if the exposured time was 2 min, the percentage would be 2.5%. When the stable degree of circumstance was C, the wind speed was 2.3 m/s and the outside concentration of the cloud was 4000 mg/m3, dimension of cloud in X axis was 782 m and in Y axis was 88 m.

CONCLUSIONThe leaky consequence of liquefied ammonia was very serious. It is necessary to take preventive measures during production, storage, transportation and using of liquefied ammonia.

Traditional Chinese Medicine (TCM) is the treasure of Chinese civilization. It embodies the characteristics and essence of the outstanding culture of China. As the indispensable platform, Chinese medicine museum plays an important role to spread the TCM culture and educate the public. This articl analyzes the difficulties and challenges of propagation and education of TCM in the museum field, explores the effective strategies from four aspects, covering the content construction, interpretation, education activities, and temporary exhibitions. Only in this way, the public education would be promoted effectively in the museum field.

Objective To inquiry the changes of serum miRNAs expression in pneumoconiosis complicated with pulmonary tuberculosis patients.Methods The study subjects (all subjects are male) were divided into three groups:I stage pneumoconiosis (38 cases)、Pneumoconiosis complicated with pulmonary tuberculosis (12 cases) and healthy control (40cases).The first two groups come from Tianjin worker's sanatorium and healthy control group came from a Hospital Health Screening Center.RT-qPCR was used to detect the expression levels of miR-21,miR-200c,miR-16,miR-204,miR-206,miR-155,let-7g,miR-30b,miR-192,miR-29a in serum.Results Compared with the healthy control group,the expression levels of miR-204,miR-206,miR-21,miR-16,miR-29a,miR-155,miR-200c in other two groups are different (P＜0.05);Compared with the I stage pneumoconiosis,the expression levels of miR-155 is significantly higher (P＜0.05) and miR-29a is significantly lower (P＜0.05).Conclusion Compared with the I stage pneumoconiosis,the expression levels of miR-155 and miR-29a are significantly different,suggesting that these two miRNAs may play a important role in the process of pneumoconiosis complicated with pulmonary tuberculosis

Objective To inquiry the changes of serum miRNAs expression in pneumoconiosis complicated with pulmonary tuberculosis patients.Methods The study subjects (all subjects are male) were divided into three groups:I stage pneumoconiosis (38 cases)、Pneumoconiosis complicated with pulmonary tuberculosis (12 cases) and healthy control (40cases).The first two groups come from Tianjin worker's sanatorium and healthy control group came from a Hospital Health Screening Center.RT-qPCR was used to detect the expression levels of miR-21,miR-200c,miR-16,miR-204,miR-206,miR-155,let-7g,miR-30b,miR-192,miR-29a in serum.Results Compared with the healthy control group,the expression levels of miR-204,miR-206,miR-21,miR-16,miR-29a,miR-155,miR-200c in other two groups are different (P＜0.05);Compared with the I stage pneumoconiosis,the expression levels of miR-155 is significantly higher (P＜0.05) and miR-29a is significantly lower (P＜0.05).Conclusion Compared with the I stage pneumoconiosis,the expression levels of miR-155 and miR-29a are significantly different,suggesting that these two miRNAs may play a important role in the process of pneumoconiosis complicated with pulmonary tuberculosis

Objective To understand the occurrence characteristics of occupational chemical incidents in China by media surveillance, to provide scientific evidences for formulating effective prevention and control strategies, and to provide new ideas for public surveillance and early warning of chemical incidents. Methods Occupational chemical incidents were collected and sorted through the Internet every day. The statistical analysis was conducted from time, region, industry, and causes of the collected incidents. Results A total of 99 occupational chemical incidents were collected in 2021, involving 356 peoples and 186 deaths. April to July was the high incidence period of events, mainly limited space poisoning and asphyxiation events. Majority of the incidents were general grade events, mainly occurring in small and medium enterprises. Guangdong Province had the most incident reporting areas. Incidents mainly occurred in chemical raw material and chemical product manufacturing industry as well as in water production and supply industry, mainly in manufacturing, cleaning and maintenance positions. The main types of poisons were asphyxiating gases and organic solvents, mainly involving hydrogen sulfide and benzene. The incidents could have been caused by lack of safety awareness, leakage of equipment, and lack of protective measures. Conclusion Occupational chemical incidents still occur frequently and cause serious harm. It is suggested that the relevant departments and employers should strengthen supervision and management, effectively manage and control operational risks, and increase supervision of key industries and positions, to ensure the health and safety of workers.

Objective: Analyzes of the monitoring results of silicosis in key occupational disease monitoring in Tianjin in 2017, providing reference for continuous monitoring, and prevention and control work of silicosis. Methods: Monitor and analyze the current state of silica dust hazard enterprises, the health status of silica dust workers, and the characteristics of newly developed silicosis cases in accordance with the national 2017 work plan for key occupational disease monitoring and occupational health risk assessment. Results: In 2017, 210 enterprises have silica dust hazard in Tianjin, silica dust workplaces exceed the standard rate is 34.73%, 5 695 workers' health examination who contact with silica dust were collected. 2 were detected occupational contraindication, the abnormal detection rate of chest examination is 3.60%, the abnormal index of lung function mainly is FVC, the abnormal rate is 15.8%. The abnormal rate increases with working years. In 2017, 193 new cases of silicosis were reported most cases were developed after years of decontamination. Most enterprises with cases had already out of market, only 7 were still producing. Conclusion The key prevention and control in Tianjin was enterprises with silica dust excess of standard, as well as older and longer working years workers, adopting effective measures to reduce the concentration of silica dust in workplace is a fundamental measure to reduce the risk of silicosis.

Objective: To provide scientific evidence for the prevention and control measures of silicosis by analyzing the epidemiological characteristics of silicosis cases reported in Tianjin city during 2001-2015. Methods: The database of silicosis cases reported in Tianjin from 2001 to 2015 was established and analyzed by SPSS 24.0 software. Results: 2 213 cases of silicosis were reported during 2001~2015 in Tianjin, 2015 of them were new cases, and fewer reports of promoting stage cases and death cases, which were129 and 69 cases. The new cases were increasing by years, mainly stage I silicosis accounting for 99.2%, the years of dust exposure were concentrated from 1970 to 1989, accounting for 69.58%. From 2001 to 2015, the median length of service at the onset of silicosis was 19.30 years, the age of the onset of silicosis is decreasing. The median of onset age in new cases of silicosis was 53.28 years, and increased year by year. There were significant differences in indirect dust working age and diagnostic age in different reporting years. Most cases were distributed in non-mental mineral product industry, and ferrous metal smelting and rolling processing industry. The work types of these cases are various. Conclusion The increasing incidence of silicosis and the shortening of dust-exposed working years suggest that the form of silicosis hazards is still severe in Tianjin. According to the epidemic characteristics of silicosis, we should strengthen the supervision and management of key industries and special investigation, carry out silicosis census and silicosis screening of dust-removal workers, and take pertinent measures to prevent and control the occurrence of silicosis.

Objective To understand the occupational hazards of dust related enterprises in Tianjin, and to provide a scientific basis for formulating regulatory policies and effectively curbing the high incidence of pneumoconiosis. Methods The basic situation of the enterprise, the occupational health management status, and the occupational health status of the workers were described and analyzed. Results Most of the enterprises exposed to dust in Tianjin were small and micro enterprises, manufacturing enterprises and private enterprises. The reporting rate of occupational hazard items was uneven (P < 0.01). As the scale of the enterprise decreased, the comprehensive training rate of occupational health, the training rate of enterprise leaders, the training rate of occupational health management personnel, the comprehensive implementation rate of occupational hazard detection and the detection rate decreased accordingly (P < 0.01). Conclusion Tianjin should focus on the supervision of small and micro enterprises, strengthen the occupational health training of small and micro enterprises, and implement hierarchical and effective supervision for enterprises of different sizes in different regions. Meanwhile, enterprises should bear the main responsibility of occupational health, so as to ensure the continuity of occupational health management measures such as occupational hazard detection and occupational health inspection.

Objective To conduct a survey on the status of noise hazards in Tianjin in 2020, to analyze the main distribution characteristics of noise hazards, and to put forward corresponding preventive and control measures. Methods A unified questionnaire was used to investigate the city-wide enterprises with more than 5 employees, normal production and operation, and noise hazards. The χ² test was used to analyze the survey results. Results There were 8 560 enterprises with noise hazards, which were concentrated in the five outer suburban districts, the four districts around the city and the Binhai New Area, mainly small and medium-sized enterprises. Totally, 223 800 people were exposed to noise. The rates of noise hazard detection and physical examination of workers were 25.88% and 17.66%, and the rate of over standard detection and the rate of abnormal physical examination were 13.09% and 1.62%, respectively. The differences in noise detection rate, over standard detection rate and physical examination rate were significant in different administrative regions, enterprise scales and industries. The detection rate and physical examination rate of enterprises in the five outer suburban districts, micro-scale enterprises, and paper products industries were the lowest, while the rate of exceeding standards was the highest in the railway, shipping, aerospace and other transportation equipment manufacturing industries. Conclusion Noise is a common occupational hazard in enterprises in Tianjin. There are a large number of people who are exposed to noise. The detection rate and physical examination rate of noise are at a low level. Individual industries have a high rate of exceeding the standard. The current situation of noise hazard prevention and control is not optimistic. It is recommended to pay attention to it and take effective intervention measures.