RESUMO
@# Objective To investigate the prevalence of the occupational hazard of organic solvent and noise in printing and Methods record medium production enterprises in Longgang District of Shenzhen City. A total of 56 printing and record medium production enterprises were selected as the study subjects by judgmental sampling method to analyze the worksite Results survey of occupational health and the key occupational hazard factors. There were 256 organic solvent samples ， detected in 56 enterprises which included a total of 148 terms and 1 358 categories of volatile constituents. The top three （ ）， - （ ） （ ） volatile constituents were toluene 35.5% n hexane 25.7% and methanol 23.8% . The top three detected samples of the （ ， ， ， ， - ， ，- ， eight key chemical occupational hazard factors benzene toluene xylene ethylbenzene n hexane 1 2 dichloroethane ） ， - ， trichloroethylene and chloroform were toluene n hexane and ethylbenzene. In the workplace air toluene was the most risk ， factor of occupational hazard factors in enterprise and in sample detection while no trichloromethane was detected. The toluene in workplace air was found to exceed the national standard with the rate of 2.6%. It showed that 27.9% of the work sites were found occupational noise hazard which was over national standard in the 10 key work sites. Only 64.3% and 57.1% enterprises - performed occupational hazard factors detection and occupational health examination. Both none or invalid toxicant proof - facilities accounted for 33.9% of the enterprises. Both none or invalid noise proof facilities accounted for 78.6% of the Conclusion ， - enterprises. The occupational hazards factor of toluene n hexane and noise were serious in printing and record ， medium production enterprises in Longgang District of Shenzhen City and the occupational health management was imperfect. The occupational regulation should be enhanced in this industry.
RESUMO
OBJECTIVE: To study the occupational exposure limit of dimethoxymethane (DMM) in workplace air. METHODS: Literature research was conducted on DMM; information on its physicochemical properties, toxicology, and occupational epidemiology was collected. Upon analyzing these data, an occupational exposure limit of DMM in workplace air was proposed according to the guidelines and principles of developing occupational exposure limits for harmful factors in workplaces. RESULTS: A total of 165 air samples were collected from DMM manufacturers, 14 of which had a DMM concentration over 3000 mg/m(3), accounting for 8.48% of all samples. Compared with the control group, the exposed employees had a significantly increased incidence of discomfort symptoms when exposed to more than 6000 mg/m(3) DMN (P < 0.01).No significant differences in the constituent ratios of abnormal results in physical examinations were found between the exposure groups and control group (P > 0.05). CONCLUSION: We recommend to set the permissible concentration-time weighed average to 3100 mg/m(3) as the occupational exposure limit of DMM in workplace air in China. This occupational exposure limit standard meets the relevant requirements of toxicology and occupational epidemiology, as well as fits well with our country's current economical and technological levels. This standard has high applicability in China's domestic settings.
