Toluene diisocyanate exposure induces oxidative stress injury in rat lung / 公共卫生与预防医学

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 (P0.05). 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.

Media surveillance of occupational chemical incidents in 2021 / 公共卫生与预防医学

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.

Toluene diisocyanate induces liver injury and affects HO-1 expression in rats / 公共卫生与预防医学

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.

The epidemiological characteristics of silicosis cases in Tianjin from 2001 to 2015 / 中华劳动卫生职业病杂志

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.

Effects of p-Phenylene diamine on liver and kidney functions of occupational exposed workers / 中华劳动卫生职业病杂志

Objective@#To study the effect of p-phenylenediamine (PPD) on liver and kidney function in occupational exposed workers.@*Methods@#Workers in a hair dye production enterprise which used p-phenylenediamine as a raw material for production were selected as the main research population. Then we conducted a questionnaire survey on the basic conditions of workers and conducted occupational health checkups on general health status, liver and kidney function. Occupational health examination assessment results were tested in Taizhou Cancer Hospital. All data was built using EpiData 3.1 software, and statistical analysis was performed using software SPSS 20.0.@*Results@#The liver function indicators including direct bilirubin, prealbumin, total protein, and white protein, globulin, aspartate aminotransferase, glutamyl transpeptidase, and total bilirubin in the workers exposed to high concentration of PPD were at high normal values, and these indicators were significantly different from low PPD concentration group (P<0.05) . The serum creatinine and serum uric acid in the renal function index were significantly higher in workers exposed to PPD than in workers exposed to low concentrations and in the control group (P<0.05) .@*Conclusion@#Occupational exposed to PPD may have a hazard to the workers’ liver and kidney function. Long-term occupational exposure to PPD may lead to increased cumulative exposure of workers, which may cause potential chronic liver and kidney damage in occupationally exposed populations.

Effects of p-phenylenediamine on lung function and health-related quality of life of workers / 中华劳动卫生职业病杂志

Objective@#To study the effects p-phenylenediamine (PPD) on lung function and health-related quality of life of occupational exposed workers.@*Methods@#This study was based on data from a company that produce hair dye containing PPD in China. Workers who exposed to PPD were selected as the study group, and workers un-exposed to PPD were selected as the control group. Questionnaires on health-related quality of life of workers using the 36-item Short Form Health Survey (SF-36) . Occupational health examination assessment results were tested in Taizhou Cancer Hospital. The lung function test includes forced vital capacity (FVC) , forced expiratory volume in one second (FEV1.0) , and ratio of FEV1.0 to FVC (FEV1.0/FVC) .@*Results@#The difference in systolic blood pressure between the PPD exposed group and the control group was statistically significant (P<0.05) . FVC, FEV1.0, and FEV1.0/FVC of the lung function indexes in the exposed group were lower than those in the control group (P<0.05) . In the health-related quality of life, body pain (P=0.002) , general health (P=0.029) , vitality (P=0.038) , and mental health (P=0.003) were lower in the exposed group than in the control group.@*Conclusion@#Occupational exposed to PPD may induce hazard to the workers’lung function and may cause detrimental effect on workers’ health-related quality of life.

Epidemiological and occupational characteristics of occupational chemical poisoning in Tianjin city during 2006-2015 / 中华劳动卫生职业病杂志

Objective@#To provide scientific evidence for the prevention and control measures of acute and chronic occupational poisoning by analyzing the epidemiological and occupational characteristics of occupational chemical poisoning cases reported in Tianjin city during 2006-2015.@*Methods@#In September 2016, based on the China Disease Control and Prevention Information System, a database of occupational poisoning cases in Tianjin from 2006 to 2015 was established. The epidemiological characteristics of occupational poisoning were analyzed including three distributions firstly, and then the occupational characteristics were analyzed such as length of service, industry distribution and source of poison.@*Results@#There were 174 occupational poisoning patients in Tianjin from 2006 to 2015, including 16 cases of acute poisoning (9.20%) and 158 cases of chronic poisoning (90.8%) , and the proportion of occupational poisoning cases reported in Binhai New Area is the highest. The number of reported cases of chronic occupational poisoning shows a downward trend. Occupational poisoning cases are concentrated mainly in the age of 40-60 years and length of service of 10-20 years. The high incidence of occupational poisoning mainly exists in the chemical raw materials and chemical manufacturing industry and general, professional equipment manufacturing industry. Acute poisoning was mainly by asphyxial gas (50.00%) , and chronic poisoning was mainly by organic solvent (43.67%) .@*Conclusion@#The distribution of occupational poisoning cases in diverse toxic types and regions in Tianjin are quite different. The occupational safety precautions of the chemical raw materials and chemical products manufacturing and occupational poisoning control work in Binhai new area should be strengthened to reduce the occurrence of occupational poisoning.

Analysis on occupational health surveillance to workers exposed to toxic environment in a city / 中华劳动卫生职业病杂志

Objective@#To understand the status of occupational health surveillance to workers exposed to toxic environment in a city, so as to provide scientific basis for strategy of occupational diseases prevention.@*Methods@#In January 2017, collecting the data of on-the-job poisonous and harmful workers occupational health surveillance in the city from January 1, 2010 to December 31, 2016 in China Information System for Disease Control and Prevention, the trend of occupational health monitoring in the city was analyzed, and the differences between diverseeconomic types, enterprise scale, industry nature and hazard factors were analyzed and compared.@*Results@#The occupational health examination rate showed an overall upward trend in workers exposed to dust in the city from 2010-2016 (t=3.607, P<0.05) , and the detection rate of occupational contraindications was on the rise in workers exposed to chemical factors (t=3.071, P<0.05). The detection rate of occupational contraindications and suspected occupational diseaseswere significant in different economic types, enterprise scale, industry nature and hazard factors (P<0.05). The detection rate of occupational contraindications was the highest among the large enterprises (1.24%) , the manufacturing industry (0.84%) and the state-owned economy (1.49%). The detection rate of suspected occupational diseases (0.04%) and occupational contraindications (1.15%) were the highest in the physical factors.@*Conclusion@#Occupational health monitoring in the city is not optimistic. It is necessary to focuson the occupational health care of manufacturing practitioners, raise the detection rate of suspected occupational diseases, and standard the occupational health check work to protect the occupational health.