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Biological Contaminants in Indoor Environments, ASTM STP 1071 1990 Jan; :190-200
Bacterial endotoxins were reviewed and discussed. The characteristics and sources of endotoxins were reviewed. Studies have indicated that endotoxins are heat stable lipopolysaccharide (LPS)/protein complexes contained within the outer membrane of gram negative bacteria that are released into the environment after lysis of bacterial cells and during active cell growth. Endotoxins from intact bacterial cells can be ingested by alveolar macrophages, a process that increases their toxicity. Gram negative bacteria are commonly found in the soil, water, and in other living organisms. They can also be released into office environments from building humidification systems. The health effects of endotoxins were discussed. Endotoxins can impair humoral and cellular host immune systems. Alveolar macrophages are considered to be the target cells following inhalation exposure to endotoxins. LPSs are able to bind to pulmonary surfactant and alter its surface properties. These effects can cause impaired pulmonary function. Chest tightness, dyspnea, fever, and wheezing are typical symptoms following inhalational exposures. Controlled inhalation studies of the effects of endotoxin laden cotton dusts in human volunteers have shown that decrements in pulmonary function that can be associated with the airborne endotoxin concentration occur. Studies in cotton mill workers have shown a dose response relationship between the incidence of chronic bronchitis and other lung problems and the endotoxin content of the cotton dust. Humidifier fever occurring in office workers has been linked to endotoxins released into the air from the humidification system. Techniques for sampling and analyzing endotoxins in bulk materials, water, and airborne dusts were described. Most procedures are based on the Limulus amebocyte lysate test. Strategies for reducing the endotoxin cotton dust were summarized. Water washing of cotton has been shown to reduce the endotoxin content of the lint in experimental card room studies. Mild washing has been shown to reduce the acute bronchoconstriction potency of cotton dust in studies in human volunteers.
NIOSH-Author; Bacteria; Cotton-dust; Proteins; Clinical-symptoms; Respiratory-system-disorders; Inhalation-studies; Epidemiology; Textile-workers; Indoor-air-pollution; Indoor-environmental-quality
Morey PR; Feeley JC Sr.; Otten JA
Biological Contaminants in Indoor Environments, ASTM STP 1071
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division