Objective: To investigate the cause of an incident of occupational contact dermatitis in a farm in Tianjin Prefecture, so as to provide insights into occupational safety. Methods: The disinfection process, use of disinfectants and individual protective measures in this farm were collected, and a field epidemiological investigation was conducted to collect the demographic characteristics, history of occupational contact, clinical symptoms, diagnosis and treatment data, and onset of disease among individuals with the same type of job. The cause of this incident was analyzed. Results: There were ten interns exposed to potassium hydrogen sulfate compounds simultaneously in this farm, and then, nine interns developed skin flushing across the body, and swelling and itching of the skin. Among these ten interns, five individuals were admitted to hospitals because of severe symptoms and were then clinically diagnosed as systemic contact dermatitis. All five individuals were cured following treatments. Epidemiological survey showed that all cases had a definite history of occupational contact with potassium hydrogen sulfate compounds but without use of any protective agents. In addition, there were thirty-five individuals with the same type of job in this farm that developed similar symptoms when they joined in the disinfection for the first time, and these individuals were self-cured following cessation to contact; however, recurrence of symptoms was found following contacts again. Conclusion This is a cluster of occupational contact dermatitis caused by exposure to potassium hydrogen sulfate compound.

Silicosis is a chronic progressive pulmonary fibrosis disease that seriously endangers the occupational health of workers. There is no effective treatment at present. It is urgent to find effective therapeutic targets and use molecular markers to intervene the process of silicosis fibrosis. As a new type of non-coding RNA, circular RNA (circRNA) has the characteristics of stable structure, long half-life, high conservation, and is specifically expressed in different species, tissues, diseases, and developmental stages, and has potential value and application prospects as a biomarker. In recent years, the regulatory role of circRNA in the occurrence and development of human diseases has become a research hotspot. Some circRNAs have been found to associate with the pathogenesis of silicosis. This article briefly described the biological characteristics and functions of circRNA, focused on the reported relationship between circRNA and pathogenesis of silicosis, summarized the current research progress of circRNA-mediated pathogenesis of silicosis, and then put forward potential directions and suggestions for further research on targeting circRNA in the diagnosis and treatment of silicotic fibrosis.

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 To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on the pathological changes, oxidative stress damage, and HO-1 expression levels in rat liver tissues. Methods Forty healthy 3-week-old SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups (control group, low-dose group, medium-dose group, and high-dose group), each with 10 rats. The rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage. TDI was administered to animals by inhalation at doses of 0, 3.06 mg/m³, 12.25 mg/m³, and 49.00 mg/m³, respectively, for 6 hours a day and 5 days a week, and continuously for 13 weeks. The control group was exposed to fresh air. The effect of TDI on pathological changes, oxidative stress damage and HO-1 expression in rat liver tissues was examined. Results Compared with the control group, the rats in the medium and high-dose TDI-exposed groups exhibited vacuolar changes, hepatocyte swelling, steatosis and other pathological changes. With the increase of the TDI dose, the gap between hepatocytes was widened, mitochondria were swollen and vacuolated, and mitochondrial cristae disappeared. The expression levels of HO-1 gene and protein in the liver tissues of the low, medium, and high dose groups were significantly higher than those in the control group (P<0.05). Compared with the control group, the number of HO-1 positive cells in the low, medium and high dose groups increased and the staining increased gradually, and the difference was statistically significant (P<0.05). Conclusion TDI exposure can cause oxidative damage to rat liver tissues and induce the expression levels of HO-1 gene and protein expression.

Objective To analyze the diagnosis cases of occupational benzene poisoning in gas station industry, and to explore the application of GC-MS technology in occupational disease diagnosis.   Methods The epidemiological method was used to describe and analyze the occupational disease diagnosis of 15 gas station workers , and qualitative screening of occupational hazard factors was performed by GC-MS.   Results All the 15 workers had more than one year's occupation history of oil refueling and unloading.  The clinical manifestations were consistent with the characteristics of chronic benzene poisoning in diagnosis of occupational benzene poisoning.  However, due to lack of evidence of occupational exposure to benzene and incomplete diagnostic data, occupational chronic benzene poisoning was not diagnosed. GC-MS technology was used to screen the occupational hazard factors in the gas station workplace, and benzene, n-pentane, n-hexane and so on were found.  Conclusion GC-MS is recommended for qualitative screening of organic solvents such as benzene when diagnosing occupational diseases for gas station workers , so as to accurately identify occupational hazard factors in workplaces and provide reliable basis for diagnosis of occupational diseases.

Objective To understand the occupational health status of gas station workers, to analyze the characteristics of early health damage, and to provide a reference for the occupational health monitoring of workers in this industry. Methods The gas station workers who underwent occupational health examination in an occupational health examination institution in Tianjin in 2021were selected as the research subjects. The examination results were statistically analyzed. Results A total of 381 gas station workers were included in this study, with a sex ratio of male to female of 1.40:1. The top three tests with abnormal results from high to low were abdominal color Doppler ultrasound (39.63%), urine routine (29.13%), and blood pressure (23.62%). The detected fatty liver accounted for 74.83% of abnormal abdominal color Doppler ultrasound. Analysis of abnormal results of different genders showed that the detection rate of abnormal blood pressure, fatty liver and liver function in males was higher than that in females (χ²=16.40, 25.40, 15.98，P＜0.05), the detection rate of high GGT in males was significantly higher than that in females (χ²=16.04，P＜0.05）. The detection rate of abnormal urine routine in females was higher than that in males (χ²=12.85，P＜0.05), and the positive rate of urine white blood cells and blood in urine were significantly higher I women than those in men (χ² =16.80, 11.66，P＜0.05). The abnormal detection rate of electrocardiogram of gas station workers increased with age (χ²=28.02，P＜0.05), and the abnormality of high blood pressure showed an increasing trend with age and working years（χ²=25.00, 15.26，P＜0.05). Conclusion The long-term exposure of gas station workers to chemical toxic substances such as organic solvents and benzene series and physical factors such as high temperature in summer and low temperature in winter will have a certain impact on health. It is suggested that employers should reasonably arrange their work systems and carry out occupational health monitoring in a targeted manner.

Objective To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on oxidative stress damage in rat lung tissue. Methods SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups,the rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage.To observe the ultrastructural and histopathology changes of lung tissue in rats.The levels of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in lung tissue were detected. The ultrastructural and histopathological changes were examined. The expression levels of HO-1 mRNA and protein were detected by Real-time PCR and Western Blot, respectively. Results The body mass, lung tissue mass, and lung organ coefficient of rats in each dose group were lower than those in the control group (P<0.05), and the body mass of rats in each group increased with the increase of exposure time (P<0.05); The results of lung histopathological examination showed that after TDI exposure,in the high-dose group, pulmonary alveolar wall hyperemia and edema were observed in the lung tissue of rats, alveolar wall thickening was observed, alveolar septa widening, and a large number of red blood cells were seen in the alveolar cavity. The results of ultrastructural examination of lung tissue showed that after TDI exposure, while in the high-dose group, the number of alveolar cells decreased, with unclear cell boundaries and irregular morphology. The levels of MDA in the lung tissue of rats exposed to TDI at various doses were higher than those in the control group (P<0.05), while the levels of GSH, GSH-Px, SOD, and CAT were lower than those in the control group (P<0.05); There was no significant difference in HO-1 gene and protein levels among rats in each group (P>0.05). Conclusion Subchronic inhalation of TDI can cause changes in the pathology and ultrastructure of rat lung tissue, leading to abnormal levels of metabolic enzymes in lung function, thereby inducing oxidative stress damage to the lungs. However, but HO-1 is involved in oxidative stress damage in the lungs induced by TDI.