Occupational Dust Exposure Analysis Of Part Carbide Production Plant In Zhuzhou City

Objective This study was part of Zhuzhou Cemented Carbide by detecting the level of dust concentration in production environments of each workshop production jobs, and the concentration of dust samples carbide cobalt, tungsten elements, and risk. Identify highrisk groups carbide dust production plant, to provide reference and basis for hard metal lung disease prevention and carbide production enterprises in occupational disease prevention.Methods 1 The survey selected Zhuzhou, Hunan four representative carbide production enterprises, including a large, two medium-sized(A and B business enterprise), a small business, through the pre-survey respondents, the final determine select mixing, milling drying, sieving, pressing, sintering, processing, sandblasting, to check packaging workshop for the study. Individual samples according to "standardize workplace air sampling monitoring hazardous substances" in distribution, sampling. The sampling time is a work shift worker time. Sentinel sentinel total dust and respirable dust sampling locations with the same individual sampling sites, sampling time is 30~90min. Dust concentration calculated GBZ/T192-2007 "Determination of dust in the air of workplace" reference. Questionnaire using "inquisitorial" survey method, survey informed consent Investigation study general(name, nationality, age, smoking status), occupational history(now work unit, where the workshop, work changes, etc.), work basic job situation(occupational hazards of the contact, the daily working hours, number of days per week,personal protective cases).2 Inductively coupled plasma emission spectrometer to detect the concentration of dust samples of cobalt and tungsten, the standard curve detection method set up six points, cobalt curve is 0,0.02,0.2,1,5,10mg/L, tungsten curve 0,0.1,1,5,25,50mg/L. Detection limit of cobalt is 0.009645mg/L, tungsten is 0.044193mg/L.Recovery of cobalt was 96.7~102.8%, tungsten recovery was 113.6~115.8%. Cobalt relative standard deviation of 2.3 to 2.6% relative standard deviation of tungsten is 3.6 to3.9%. Sample before injection after microwave digestion and dilute to 10 m L.3 Four companies for dust and cobalt, tungsten chemical substances were used in Singapore Occupational exposure to occupational health risk assessment a semi-quantitative risk assessment methods and risk assessment of occupational hazard index method, and the results of the two methods were compared.Results 1 The total survey of a large enterprise,two medium-sized enterprises,a small business. Total collected individual respirable dust samples 203, collect total dust samples 101, collect respirable dust samples 97. Wherein individual respirable dust concentrations geometric mean separately were 0.22mg/m3 、 1.10mg/m3 、0.63mg/m3、0.32mg/m3,sentinel total dust concentrations geometric mean separately were 0.58mg/m3 、 2.90mg/m3 、 0.65 mg /m3 、 1.02mg/m3, sentinel respirable dust concentrations geometric mean separately were 0.19mg/m3、0.52mg/m3、0.26mg/m3、0.24mg/m3. Four companies Sentinel total dust/respirable dust concentrations ratio geometric mean were 4.45. Total dust concentrations detect excessive rate was4.95%. Large enterprises old craft dust concentrations higher than the new technology(P<0.05).2 The number of samples of cobalt, tungsten detected is consistent with the number of detected dust Including large, medium(A, B), geometric cobalt concentration of respirable dust samples in individual small four companies mean separately were 0.021mg/m3、0.084mg/m3、0.006mg/m3、0.192mg/m3,sentinel total dust cobalt concentrations geometric mean separately were 0.020mg/m3、0.090mg/m3、0.007 mg /m3 、 0.204mg/m3, sentinel respirable dust cobalt concentrations geometric mean separately were 0.003mg/m3、0.016mg/m3、0.003mg/m3、0.045mg/m3.Total dust exceeded the rate of cobalt element detection was 17.82%.Large enterprises old craft cobalt concentrations higher than the new technology(P<0.05).Tungsten in four individual enterprises respirable dust samples were geometric mean were 0.243mg/m3、0.839mg/m3、1.005mg/m3、0.371mg/m3,sentinel total dust Tungsten concentrations geometric mean separately were 0.233mg/m3 、 0.716mg/m3 、 0.269 mg /m3 、0.863mg/m3,sentinel respirable dust tungsten concentrations geometric mean separately were 0.037mg/m3 、 0.227mg/m3 、 0.067mg/m3 、 0.240mg/m3. Total dust tungsten concentrations detect excessive rate was3.96%. Large enterprises old craft tungsten concentrations higher than the new technology(P<0.05). 3 The results of the four companies of dust occupational health risk assessment workshop materials show the highest risk, followed by processing workshop, molding workshop and finished workshop, mostly low-risk. Risk assessment method and index the results obtained semiquantitative risk assessment method Singapore consistent. Cobalt dust samples at the highest risk level workshop materials, and other workshop, mostly low-risk or no risk,tungsten workshop all risk levels are low risk or no risk.Conclusions Medium-sized enterprises A dust concentration is highest in 4enterprises,various types of mixing, drying and milling and sieving of cobalt dust, high concentrations of tungsten,The old process is relatively new process in dust and cobalt,tungsten, high concentrations(P<0.05),higher raw material workshop(mixing, milling dried, sieved) occupational health risks.We should focus on strengthening the mixing,milling dried, sieved section of occupational health care, and accelerate pressing,sintering, processing from the old to the new process technology transition.