RESUMO
ObjectiveTo analyze the measures and effects of comprehensive noise control in an automobile engine manufacturing enterprise. Methods An automobile engine manufacturing enterprise with noise exposure work-sites was selected as the research subject. The noise hazard status of the enterprise was investigated. The noise hazard exceeded the national standard in work-sites was comprehensively treated. The treatment effect was analyzed. Results A total of 395 work-sites exposed to noise were detected. Among them, 16 work-sites exceeded the national noise standard, with the rate of 4.1%. The work-sites with noise exceeding the national standard were mainly in the machine workshop and the casting workshop, with normalization of equivalent continuous A-weighted sound pressure level to a nominal eight hours working day (LEX,8h) ranging from 86.8 to 89.2 and 85.2 to 90.2 dB(A), respectively. In addition, the classification of occupational noise exposure of the mold protection group in the casting workshop was level Ⅱ, and classification of occupational noise exposure of other work-sites with excessive national standard was grade Ⅰ. After the enterprise implemented noise control measures such as process reform, equipment replacement, sound insulation, noise reduction, sound absorption, and vibration isolation, the LEX,8h of nine positions were lower than those before rectification ［(86.7±1.1) vs (83.3±1.3) dB(A), P<0.01］. Conclusion The use of comprehensive control measures can achieve the purpose of reducing noise from the sources, and can be used for reference by relevant enterprises with noise hazards.
RESUMO
Objective To analyze and evaluate the occupational hazards,engineering protection measures and risk levels in an oil terminal project.Methods Engineering analysis,occupational health survey,inspecting -testing and semi -qualitative semi-quantitative evaluation method (MES method)were used to analyze the production process,the type of occupational hazards,characteristics and concentrated/strong degrees and engineering protection measures of the project. Also,the occupational health risk and the effect of engineering protection were assessed.Results The main occupational hazards of this project were dust,solvent naphtha,benzene,toluene,xylene,hexane,non -methane hydrocarbons, carbon monoxide,carbon dioxide,manganese and its inorganic compounds,hydrochloric acid,hydrogen sulfide,noise, high temperature,power frequency electric field,welding electric arc and so on.Approximately,16.67%of noise samples and 66.67% of high temperature samples exceeded the Chinese National Occupational Health Standards.Except for noise of the fuel pump shed and high temperature of 100000 tons pier and fuel tank,the occupational hazards of other jobs were in line with the national occupational health standards.In normal conditions,the occupational risk levels of all positions were 5 (slightly hazardous),while in special conditions,the occupational risk level of repair welders was 5 (slightly hazardous),of pier operators and tank farm operators were 1 (extremely dangerous),of sewage treatment workers,boiler room operators and electricians were 3 (significant risk ).Conclusion This project can take effective engineering protective measures to control occupational hazards and risk management of special conditions need to be strengthened.