Microbiological air contamination from machining fluids.
NIOSH 2004 Dec; :1-14
Workers exposed to machining fluid aerosols may have an increased risk in developing a variety of respiratory and skin diseases, such as allergies, asthma, hypersensitivity pneumonitis, and dermatitis. About 1.2 million workers in the United States are occupationally exposed to metalworking fluids (MWFs). Microbial contamination of water-based MWFs is one of the suspected causes for respiratory diseases but the exposure-response relationship is not well understood. One reason for this knowledge gap is that insufficient information has been available so far on the composition and concentration of airborne microorganisms at metalworking sites. We have studied the aerosolization of microorganisms and mist with a laboratory-scale set-up, which allows investigating one variable at a time. As a major part of this study, a laboratory-scale grinding simulator was developed and tested. It was experimentally proven that the microbial concentration in the MWF or the MWF type did not affect the aerosolization potential of microorganisms. Hydrophobic microorganisms were found to be easier to aerosolize from MWFs than hydrophilic ones and increasing microorganism size resulted in decreasing the aerosolization potential. When MWF was contaminated with bacteria the aerosolization of fine and ultrafine (0.2 -1 microm) particles was found to increase by a factor of 25 for a soluble oil and by a factor of 50 for a semisynthetic fluid. Endotoxin analysis confirmed that fine particles contained microbial cell wall fragments. Field test showed that the concentrations obtained in the laboratory simulated realistic field situations and that fine and ultrafine particles can easily migrate from production areas to other areas in the plant.
Metalworking-fluids; Aerosols; Aerosol-particles; Microorganisms; Analytical-processes; Analytical-methods; Nanotechnology
Department of Environmental Health, 107 Kettering Building, University of Cincinnati, P.O. Box 670056, Cincinnati, OH 45267
Final Grant Report
NTIS Accession No.
Work Environment and Workforce: Mixed Exposures
National Institute for Occupational Safety and Health
University of Cincinnati