Endotoxin levels in farming: absence of symptoms despite high exposure levels.
- 31 May 1989
- journal article
- research article
- Published by BMJ in Occupational and Environmental Medicine
- Vol. 46 (6), 412-416
- https://doi.org/10.1136/oem.46.6.412
Abstract
The endotoxin concentration in air was measured in farms where 11 farmers had experienced febrile reactions or allergic alveolitis and in a random sample of farms with 17 symptomless farmers. Samples were obtained during normal dairy farming in eight reference farms (background samples) and in all farms during the handling of material which had probably caused symptoms or disease or, in reference farms, maximal spore exposure (worst case samples). In addition, parallel samplers were used in reference farms, one with a cyclone (5 .mu.m cutoff) and one without, to measure the dust and endotoxin concentrations in the respirable fraction and total dust. The endotoxin worst case values varied from < 0.01 to > 50 .mu.g/m3 in symptom farms (median 6.4 .mu.g/m3, geometric mean 2.2 .mu.g/m3) and from < 0.01 to > 50 .mu.g/m3 in reference farms (median 42 .mu.g/m3, geometric mean 29 .mu.g/m3). This difference was not statistically significant. The background values in reference farms were 1.3 (median) and 0.4 (geometric mean) .mu.g/m3. The differences between samples with and without cyclone and between background and worst case samples were statistically significant (p < 0.02). About 75% of the activity was found in the non-respirable fraction. No correlation was found beteween exposure to endotoxin and symptoms in farmers. There were weak, but statistically significant, correlations between endotoxin concentrations and total spore count or dust concentrations. The surprisingly with endotoxin values in the respirable fraction of air from environments which apparently did not cause symptoms raises the concern that the Limulus amebocyte assay might be sensitive to other components in the dust rather than endotoxin.Keywords
This publication has 18 references indexed in Scilit:
- Incidence of Organic Dust Toxic Syndrome and Allergic Alveolitis in Swedish FarmersInternational Archives of Allergy and Immunology, 1988
- Collection of airborne micro‐organisms on Nuclepore filters, estimation and analysis—CAMNEA methodJournal of Applied Bacteriology, 1986
- Endotoxins in the agricultural environmentAmerican Journal of Industrial Medicine, 1986
- Exposure to cotton dust in an experimental cardroom.Occupational and Environmental Medicine, 1984
- Molecular mechanisms in endotoxin feverInflammation Research, 1983
- Airborne Bacteria, Endotoxin and Fungi in Dust in Poultry and Swine Confinement BuildingsAihaj Journal, 1983
- Gelation ofLimulusAmoebocyte Lysate by Simple PolysaccharidesMicrobiology and Immunology, 1982
- Investigations on the specificity of the Limulus test for the detection of endotoxin.1974
- Stomaching: a new concept in bacteriological sample preparation.1972
- Effects in man and rabbits of inhalation of cotton dust or extracts and purified endotoxinsOccupational and Environmental Medicine, 1969