Investigation On Occupational Health Status Of The Refractory Brick Enterprises In A Region At Liaoning Province

Occupational disease is very popular at the refractory brick enterprises,and the dust from the production assembly line is prominent facts for these occupational hazards.On account of the diverse processing condition and raw material used in the industry,the occupational hazards are different,and the grade of harm is not the same.Therefore,it is practically significant to identify,evaluate and control occupational hazards at refractory brick enterprise for the protection and promotion of the workers’ health condition.Purpose:The alkaline refractory brick enterprises of different scale at a region in Liaoning Province were investigated: to know the status of occupational hazards of the alkaline refractory brick enterprise at this region;to provide the benchmarking data in the same industry for protection of occupational hazards,monitoring and management of occupational health,prevention of occupational diseases;to make the suggestions to further protect workers’ occupational health;to provide scientific basis for supervisory departments to carry out key supervision for the targeted members or targeted region.Method:A total of 23 alkaline refractory brick enterprises with different size in 2016 in Liaoning province were selected as the research object.The following list of items are investigated: the project investment,output value and occupational health expenditure,production time,main products,raw and auxiliary materials,the production process,the types of occupational hazards,the occupational hazards of protective measurements and equipment operating results,the use of personal occupational protection supplies,occupational health care and occupational health management measurements.Total of 276 dust monitoring locations,115 toxic substances monitoring locations,138 noise monitoring locations and 23 high temperature monitoring locations in 23 enterprises were measured for their occupational health testing.Microsoft Excel was used for data input,and the data analyses were done by SPSS21.0 statistical software.The mean ± standard deviation and the counting data rate were extracted from the analyses.The variance analysis was used to compare the differences or intensities of occupational hazards in different enterprises and different positions.The t test was used to compare the differences of occupational hazards in different building period of the enterprises and different positions..The difference of the abnormal rate of occupational hazards between different enterprises and different jobs were analyzed by Fisher’s exact probability method,with P <0.05 as the difference of statistically significant level.Results:1.According to the size of the enterprise,among these 23 enterprises,5 of them are microenterprises,accounting for 21.8%;9 of them are small enterprises,accounting for 39.1%;9 of them are medium-sized enterprises,accounting for 39.1%.According to the time division of the "Law on Prevention and Control of Occupational Disease".7 enterprises were put into operation before the implementation,accounting for 30.4%.Others are put into production after implementation.By category of total employee,there are total of 3135 employees among 23 enterprises,including 598 management and other staff members,2537 production line workers,with 2425 of them（95.6%）are male and 112 of them（4.4%）are female workers.The total population of male workers is obviously more than female workers.2.Total of 9 enterprises has normal operation in the dust-proof facilities among the enterprises surveyed,accounting for 39.1%.About 26.1% of these enterprises are equipped with facilities to prevent toxic air.Total of 9 enterprises has normal operation in the noise prevention facilities among the enterprises surveyed,accounting for 39.1%.Overall,the operating conditions of the protective facilities are not satisfied.15 of these 23 enterprises have normal dust mask distribution for their employees,accounting for 65.2%,2 of them has the normal use of anti-noise earplugs,accounting for 8.7%.Overall,the personal protective equipment management is not satisfied.The total cost of professional health of 23 enterprises was 20,000 to 120,000 yuan,with an average of 59,400 yuan/enterprise.3.The determination examination of free silica content from dust is conducted for these 23 enterprises,with the content of 1.6% to 8.1%,an average of 4.97%,which are less than 10% and could be classified as particles not otherwise regulated.4.The dust C_TWA and C_STEL level are measured for 6 processes: feeding,crushing,mixing,molding,drying,packaging in these investigated enterprises.The results showed the statistically significant difference of dust C_TWA and C_STEL（P <0.05）for these processes.It is found that the dust C_TWA and C_STEL of the smashing process are higher than the other positions,while dust C_TWA in the drying job is lower than other positions.5.Comparing the dust C_TWA and C_STEL in different scale enterprises,the results showed that the difference in dust C_TWA and C_STEL were statistically significant（P < 0.05）,and the microenterprise dust C_TWA and C_STEL were higher.6.The level of the toxic substances including phenol,formaldehyde,nitric oxide,nitrogen dioxide,carbon monoxide does not exceed the limits among these 23 enterprises,which is in line with national occupation exposure limits.7.Comparison of 23 companies in different noise intensity level,noise intensity differences between them,according to the results of the post was statistically significant（P < 0.05）,the noise intensity level at molding positions is higher.8.Drying position WBGT above 25 ℃,belongs to the high temperature work position.The temperature is beyond the limitation for the drying position.Compared with the high temperature of drying in different scale enterprises,the results showed that the difference was not statistically significant（P > 0.05）.Conclusions:1.The determination of free silica from the dust of the alkaline refractory brick enterprise in the region is less than 10%,which belongs to particles not otherwise regulated.2.The dust,noise and high temperature are the main occupational hazards of the investigated refractory brick enterprises,and the level of the toxic substances including phenol,formaldehyde,nitric oxide,nitrogen dioxide,carbon monoxide does not exceed the limits among these 23 enterprises.3.The dust levels at smashing positions,mixing positions,forming position are higher.It is the key position for the dust pollution control in the refractory brick enterprises.The noise level is bigger at smashing position and forming position.It is the key production position for the noise hazard control in the enterprises.The temperature is beyond the limitation for the drying position.It is the key production position for high temperature hazards control.4.The over-standard pollution of the dust concentration of the microenterprises is the most severe among the investigated enterprises.