Objective : To investigate the effect of exposure to low concentrations of benzene on miR-155 and miR-223 expression in peripheral blood lymphocytes among workers with benzene exposure. Methods : A hundred male employees at a risk of exposure to benzene (the exposed group) were randomly sampled from two small metal products manufacturing enterprises and one medium-sized chemical raw material and chemical products manufacturing enterprise in Ningbo City, Zhejiang Province, and 60 age-matched male employees without benzene exposure were randomly selected as the unexposed group. Age, body mass index ( BMI ), smoking status, alcohol consumption, disease history, medication history and routine blood testing results of subjects were collected using a questionnaire survey. The 8-hour time weighted average concentration ( CTWA ) of benzene was measured in the workplace using thermal desorption gas chromatography, and the urine 8-hydroxy-2' deoxyguanosine ( 8-OHdG ) levels were determined using high-performance liquid-chromatography tandem mass spectrometry (HPLC-MS/MS). The miR-155 and miR-223 expression was quantified in peripheral blood lymphocytes using quantitative fluorescent reverse transcription-polymerase chain reaction assay, and the factors affecting miR-155 and miR-223 expression were identified using multivariable logistic regression analysis. Results : The subjects in the exposed group had a mean age of ( 31.17±7.30 ) years, and were exposed to low concentrations of benzene ( CTWA, 0.05 to 0.30 mg/m3 ) , while the subjects in the unexposed group had a mean age of ( 32.52±6.15 ) years. There were no significant differences between the exposed and unexposed groups in terms of age, BMI, proportion of smokers or proportion of alcohol consumers ( P>0.05 ). There was no significant difference in the median relative miR-155 expression between the exposed and unexposed groups ( 0.953 vs. 1.293, P>0.05 ), and lower median relative miR-223 expression was quantified in the exposed group than in the unexposed group ( 0.540 vs. 1.433, P<0.05 ). Multivariable logistic regression analysis revealed that down-regulation of miR-223 expression correlated with exposure to benzene ( OR=2.719, 95%CI: 1.308-5.651 ). Conclusion Down-regulation of miR-223 expression may be associated with exposure to low concentrations of benzene.

Objective: To analyze the characteristics of acute pesticide poisoning in Ningbo, and to provide scientific basis for the prevention and control strategy. Methods: In February 2017, the pesticide poisoning report card of Ningbo from 2011 to 2016 was drawn from the China Disease Control and prevention information system. The data of the report card was organized by Excel and analyzed by SPSS19.0 software. Results: 2593 cases of acute pesticide poisoning were reported in Ningbo from 2011 to 2016, 125 deaths, and the case fatality rate was 4.82%. The productive pesticide poisoning and unproductive pesticide poisoning were 299 and 2294, respectively, the ratio was 1: 7.67. The case fatality rate were 0.33% and 5.41%, respectively. The difference was statistically significant (χ²=14.83, P<0.01). The productive Pesticide poisoning mainly occurred from July to September (55.85%) , the unproductive pesticides mainly occurred from April to June (30.64%) and July to September (30.34%). The seasonal distribution of the pesticide poisoning in the two groups was statistically significant (χ2=82.21, P<0.01). The productive pesticide poisoning in male (80.27%) was significantly higher than the proportion of unproductive pesticide poisoning (52.09%) , the differences in gender composition between the two types of pesticide poisoning was significant (χ2=84.97, P<0.01). The productive pesticide poisoning from 55 to 65 years old group was in the largest number (35.45%) , and the distribution of unproductive pesticide poisoning was uniform in each age group including 25 years old and above, the difference in age composition between two types of pesticide poisoning was statistically significant (χ2=177.84, P<0.01). All of the 10 counties of Ningbo had reports of pesticide poisoning. The counties with more reports were Ninghai county (18.28%) , Fenghua district (14.69%) and Yuyao (12.42%). The acute pesticide poisoning was mainly caused by pesticides and herbicides, mainly in organophosphorus (45.74%) and paraquat (16.81%) . Conclusions At present, the pesticide poisoning in Ningbo is given priority to unproductive pesticide poisoning currently, seasonal distribution characteristics was obvious, and occurred both in different sex and age groups, suggesting that the relevant departments should carry out targeted health education, and strengthen the management of high toxic and highly toxic pesticides.

Objective: To investigate the incidence, distribution features, and incidence trend of occupational diseases in Ningbo, China, from 2006 to 2015. Methods: In February 2016, the data on occupational disease report cards in the occupational disease and occupational health information system from 2006 to 2015 were collected to perform a comprehensive analysis of the types, incidence trend, population characteristics, and enterprise characteristics of occupational diseases. Results: There were 845 new cases of occupational diseases in Ningbo from 2006 to 2015, among which 596 (70.53%) were pneumoconiosis; there were 445 (74.66%) cases of stage I pneumoconiosis, 73 (12.25%) cases of stage II pneumoconiosis, and 78 (13.09%) cases of stage III pneumoconiosis; silicosis (59.76%) was the most common type of pneumoconiosis. Of all patients with occupational diseases, 84.97% were male, 64.50%were aged 35-55 years, and 63.67% had 5-20 working years. Most of the patients with occupational diseases worked in small and medium-sized private (or foreign) enterprises; the most common industries were black metal smelting and rolling (38.76%) , construction (17.11%) , and non-metallic ore mining (13.09%) . A total of 51.28%, 10.26%, and 7.69% of the patients with occupational poisoning worked in the electric apparatus manufacturing industry, furniture manufacturing industry, and chemical raw material and chemical product manufacturing industry, respectively. The cases of occupational diseases are mainly distributed in Yuyao City (24.62%) , Yinzhou District (23.91%) , and Ninghai County (15.62%) . Conclusion Pneumoconiosis is the most common type of occupational disease in Ningbo and most of these patients work in small and medium-sized private (or foreign) enterprises. The supervision of small and medium-sized private enterprises should be enhanced to protect workers’ health.

Objective: To Assess occupational health risks of exposuring to low concentrations (lower than occupational exposure limit, OEL) benzene, toluene and Xylenes. Methods: Qualitative evaluation, semi-quantitative evaluation and quantitative evaluation from guidelines for occupational health risk assessment of chemicals in the workplace were conducted to assess occupational health risks exposure to benzene compounds in different workplaces of 5 manufacturing enterprises, respectively. Results: Concentrations of benzene, toluene and Xylenes in all workplaces were lower than OEL. Qualitative evaluation showed that occupational health risk level was 4 exposure to benzene and Xylenes in all workpalces, while 2 exposure to toluene. Semi-quantitative evaluation showed low level (2 of 5) risks in all workplaces exposured to benzene compounds excepted 4 workpalces exposured to benzene, the latter was moderate (3 of 5) . Quantitative evaluation gave unacceptable carcinogenic risk (higher than 10^-4) of benzene in the wood toy manufactory, and the highest risk was (1.48~5.26) ×10^-4. The occupational health risks of benzene and Xylenes were all unacceptable (HQ>1) in 9 workplaces. Conclusion There still need more attention to occupational health risks exposure to benzene, toluene and Xylenes lower than OEL.

Objective: To analyze the occupational health surveillance data of toxic and harmful workers in Ningbo, and provide scientific basis for making protective measures. Methods: To export the occupational health surveillance data of toxic and harmful workers reported by occupational health examination institutions in Ningbo during the January 1, 2011 to December 31, 2017 from the China Information System for Disease Control and Prevention, and analyze the trend of the suspected occupational disease and occupational contraindication detection rate, and compare the the health status of workers in different industry nature, economic type, enterprise scale and occupational hazards. Results: From 2011 to 2017, the number of occupational health surveillance of toxic and harmful workers in Ningbo was increasing year by year. The detection rates of suspected occupational diseases and occupational contraindications generally showed a downward trend (P<0.05) . In 2017, the distribution of occupational health care for toxic and harmful workers in Ningbo was mainly based on manufacturing (187 681/220 895, 84.96%) , private economic enterprises (103 960/220 895, 47.06%) and small enterprises (100 357/220 895, 45.43%) , Workers exposed to chemical poisons had the largest number of physical examinations (101 813/220 895, 46.09%) . The highest detection rates of suspected occupational diseases were mining industry (2/1225, 0.16%) , collective economic enterprises (4/2622, 0.15%) and small enterprises (88/100 357, 0.09%) . The highest detection rates of occupational contraindications were rental and business services (16/1 320, 1.21%) , private economic enterprises (1 190/103 960, 1.14%) and small enterprises (995/100 357, 0.99%) . In addition, workers exposed to dust had the highest detection rate of suspected occupational diseases (57/46 740, 0.12%) and workers exposed to physical factors had the highest detection rate of occupational contraindications (1207/69 567, 1.74%) . There were significant differences between the detection rate of suspected occupational disease and occupational contraindication in different industries, economic types, enterprise scale and occupational hazards (P<0.05) . Conclusion The occupational health surveillance of toxic and harmful workers in Ningbo has been strengthened year by year, attention should be paid to small, private enterprises, and strengthen the supervision of occupational health and further standardize the work of occupational health examination so as to effectively protect the health of the occupational population.

Background The contradiction between science and operability has always existed in the model of classified occupational health supervision and management. Comprehensive risk assessment method for occupational disease hazards of employers provides risk grading and classification for occupational health management, and it's a new attempt to explore classification supervision and law enforcement. Objective To apply a comprehensive risk assessment method for occupational disease hazards of employers to estimate health risk level of wood furniture enterprises, discuss its advantages and disadvantages, and provide a basis for improving the classified management of occupational health. Methods Seven typical factories were selected in counties with highly concentrated wooden furniture manufacturing. Occupational health field investigation and testing were carried out to estimate occupational disease hazard risk level (Ⅰ, Ⅱ, and Ⅲ). A self-rated checklist was applied to score occupational health management status by interviewing employers, one by one, and to determine occupational health management status grade (A, B, and C) by the score. Thus, a comprehensive risk level (Class A, Class B, and Class C) of a specific factory was obtained from a matrix of occupational disease hazard risk level and management status grade. Risk verification was carried out based on any abnormality reported by regular occupational physical examination in past 3 years. Results Defects in occupational health management were identified in all 7 factories, among which 6 were grade C with key nonconformities (poor), and 1 was grade B (medium). Disqualified occupational disease hazards were found in 6 of 7 factories, and the workstation-specific disqualified rates were 26.09% (12/46) for noise, 14.71% (5/34) for wood dust (hard), and 12.50% (1/8) for xylene. Level Ⅱ (medium) of occupational disease hazard risk was estimated in 5 of 7 factories, while level Ⅲ (high) in 2 factories. All 7 factories were class C (high risk) accessed by the comprehensive risk assessment method for occupational disease hazards. The occupational health surveillance documents showed 636 batches of regular occupational physical examination were ordered by the 7 employers, and a total of 37 workers from 5 factories reported abnormalities in physical examination, among which 3 workers reported dust exposure and 34 workers reported noise exposure. Conclusion The comprehensive risk assessment method for occupational disease hazards of employers is not able to perform with satisfaction in occupational health classification of wooden furniture manufacturing factories yet. It is necessary to expand the pilot to improve this assessment method and develop an efficient supervision mechanism to ensure the authenticity of the data before it is popularized and applied in classified occupational health management.