Acute respiratory effects of endotoxin-contaminated machining fluid aerosols in guinea pigs.
Exposure to machining fluid aerosols in the automotive industry is associated with a variety of respiratory symptoms including cross-shift changes in pulmonary function, cough, asthma, and phlegm. Lubricating and cooling fluids used in machining operations are predominantly water and thus are susceptible to microbial growth. In the present study, the role of endotoxin in the acute pulmonary injury produced by machining fluid aerosols was examined in guinea pigs. Animals were exposed to nebulized water, unused machining fluid, or used machining fluid. At the end of a 3-hr exposure, specific airway conductance (SGaw) was not affected by exposure to the vehicle water, but was decreased in a dose-dependent manner by exposure to aerosols of the used machining fluid. SGaw decreased from preexposure baseline values by 0, 7, and 40% in animals exposed to 1, 10, and 100 mg/m3 used machining fluid, respectively. These exposure levels also produced acute lung injury as evidenced by changes in cellular and biochemical indices in lavage fluid. These adverse respiratory effects may have been due to microbial contamination of the used machining fluid as the aerosol exposures were associated with airborne endotoxin concentrations of 0.3, 1.9, and 5.3 micrograms/m3, respectively. Animals exposed to aerosols of the endotoxin-free unused machining fluid had no statistically significant adverse functional, cellular, or biochemical effects except for a fourfold increase in neutrophils at 100 mg/m3. These results suggest that contamination of machining fluid during use or storage may lead to the adverse respiratory effects of aerosolized machining fluids.(ABSTRACT TRUNCATED AT 250 WORDS)
Gordon
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Department of Environmental Medicine, NYU Medical Center, Tuxedo 10987.
D000280:Administration, Inhalation; D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000633:toxicity*; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D007219:Industrial Oils / Q000633:toxicity*; D008171:Lung Diseases / Q000139:chemically induced*; D008297:Male; D009994:Osmolar Concentration; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000187:drug effects*; D012680:Sensitivity and Specificity
D000336:Aerosols; D004731:Endotoxins