发电厂作业人员工频电磁场职业暴露现况调查

目的探讨发电厂作业人员工频电磁场职业暴露现况。方法按发电量不同,抽取3家300 MW、3家600 MW、2家1 000MW共8家发电厂作为研究对象,对存在工频电磁场的作业环境进行检测,对其中作业人员进行个体磁场的测量。以我国国家标准GBZ 2.2-2007及国际非电离辐射防护委员会规定的导出限值对结果进行评估。结果对发电厂共510个点的作业环境进行了检测,电场强度的中位数为0.005 kV/m,最大值为12.080 kV/m,有6个点超过了10 kV/m,占总数1.18%,有27个点超过了5 kV/m,占5.29%;磁场强度的中位数为7.39μT,最大值为318.00μT,有15个点超过100μT,占2.94%。其中电场强度超过5kV/m的点均在高压输电线下方(包括主变的出线端及升压站的室外设备)。作业人员工频磁场日暴露水平在0.80~1.36μT之间。结论发电厂作业人员在高压输电线下方作业时有短时接触高剂量工频电场的危险。

Occupational exposure level of power frequency electromagnetic fields among workers in power plants

Objective The exposure level of power frequency electromagnetic fields(PF-EMFs)among workers in the power plants were investigated.Methods 8 power plants with varied powering level,including 3 with 300 MW level,3 with 600 MW level and 2 with 1 000 MW level,were studied.The PF-EMFs values of the working environment were measured and individual magnetic field(MF) doses of the workers were surveyed,too.The results were evaluated with reference values announced by GBZ 2.2-2007 and international commission on non-ionizing radiation protection.Results Totally 510 worksites in these power plants we measured.The median value of electric field(EF)was 0.005 kV/m with the maximum value of 12.080 kV/m.The EF values at 1.18% worksites were over 10 kV/m and 5.29% worksites,which were all under the high voltage transmission line,over 5 kV/m.The median value of MF value was 7.39 μT with the maximum value of 318.00 μT.The MF values at 2.94% worksites were over 100 μT.The personal exposure level of PF-MF during a work shift ranged from 0.80 μT to 1.36 μT.Conclusion The workers in power plants were at risk with short-term exposure to high-level PF-EMFs.