Occupational Health Monitoring of Computer Numeric Controlled (CNC) Lathe Machinists Exposed to Metal Aerosols

Background: Metal working fluids (MWFs) sprayed through lathe machine operations in the air, are considered as hazardous chemical constituents of working room air. MWFs are detrimental for respiratory system and skin and are also suggested as a probable carcinogens. Materials and Methods: Occupational exposure of a representative group of lathe machine operators exposed to MWFs and a group of assembly workers without active exposure were monitored. Measurements of lung function parameters such as forced expiratory volume in one second (FEV1), forced volume capacity (FVC) and FEV1/FVC of exposed and control groups were obtained after cross-shift exposure to MWFs. Results: Exposure of the majority of lathe machine operators was in excess of the occupational exposure limit for MWFs in the range of 0.1-19.0 mg/m3 with the mean of 8.51 and standard deviation of 2.80 mg/m3. Exposure of the control group (assembly workers) to MWFs was below the sensitivity of analytical method. Differences of predicted lung function parameters (FEV1, FVC) between the exposed and the control population were significant (p 0.001). Correlation coefficient of lung function parameters of FEV1 and FVC with cross-shift exposure was also significant (p 0.001). Conclusion: Considering occupational monitoring of lathe machine operators exposed to MWFs and depression of their lung function parameters, implementation of standard control measures along with periodic lung function monitoring should be done.