Aerosolization of fine particles and endotoxin from metalworking fluids contaminated with microorganisms.
Wang-H; Grinshpun-S; Reponen-T
American Industrial Hygiene Conference and Exposition, May 21-26, 2005, Anaheim, California. Fairfax, VA: American Industrial Hygiene Association, 2005 May; :213
Metalworking fluid (MWF) exposures have been associated with adverse health effects, such as dermatitis, respiratory symptoms, asthma, and in some cases hypersensitivity pneumonitis. No sufficient information has yet been collected on the size distribution of particles aerosolized from MWFs contaminated with microorganisms and airborne endotoxin concentration. We have recently developed a laboratory-scale setup, which simulates grinding operations in the MWF industry. Our preliminary study with this simulator showed increased aerosolization of fine particles from semisynthetic MWF after the fluid was inoculated with Pseudomonas fluorescens under laboratory-controlled conditions. In the present study, we investigated the aerosolization of fine particles and endotoxin from two types of water-soluble MWFs-semisynthetic MWF and soluble oil-after the fluids were inoculated with P. fluorescens in the laboratory. The simulator was also utilized to test used fluids that were brought from the field sites. The concentration of fine particles was measured using a condensation nucleus counter (P-track, model 8525, TSI Inc.). Particle size distributions and collection of particles for endotoxin analysis were performed by an electrical low-pressure impactor (ELPI; 3935 series, Dekati Ltd., Tampere, Finland). The endotoxin analysis was performed with limulus amoebocyte lysate assay. It was found that after bacterial inoculation, semisynthetic MWF had a greater increase of fine particle aerosolization than soluble oil. The peak of the fine particles aerosolized from used MWFs (aerodynamic diameter, da = 0.029 um) and that from MWFs inoculated with bacteria (da = 0.037 um) were smaller than that of pure bacterial water suspension. Particles at the size smaller than intact bacterial cells contained significant concentration of endotoxin. This indicates that some of the fine particles may come from the cell wall fragments of the bacteria in the MWFs.
Aerosols; Aerosol-particles; Endotoxins; Metalworking-fluids; Metalworking-industry; Metalworking; Microorganisms; Airborne-particles; Air-contamination; Laboratory-testing; Laboratory-techniques; Simulation-methods
Work Environment and Workforce: Mixed Exposures
American Industrial Hygiene Conference and Exposition, May 21-26, 2005, Anaheim, California
University of Cincinnati, Cincinnati, Ohio