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Endotoxin exposure and respiratory outcomes among dairy, feedlot, and grain elevator workers in Colorado.

Reynolds S; Cranmer B; Keefe T; Mehaffy J; Serrano Martinez A; Saito R; Tessari J; Burch J; Koehncke N; Wood E; Burch L; Siegel P
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois. Fairfax, VA: American Industrial Hygiene Association, 2006 May; :42
Gram-negative bacterial endotoxins play a key role in respiratory disease affecting more than one million U.S. agricultural workers. This project uses a novel Recombinant Factor C (rFC) assay and GC/MS to evaluate the role of endotoxin exposures and genetis in respiratory outcomes among agricultural workers. Pre-work shift measurements included spirometry, symptoms, and blood collection for TLR4 genotyping. Personal samples were collected using IOM inhalable samplers during the workshift. Spirometry and symptoms were remeasured after the workshift, and nasal lavage fluid was collected for cytokine measurement. Results from the first 55 participants are reported here. Overall inhalable dust levels ranged from 0.59 to 76 mg/m3; endotoxin levels ranged from 62 to 34,808 EU/m3. At grain elevators (n = 20) dust and endotoxin exposures averaged 12 mg/m3 and 2,803 EU/m3. Exposures averaged 4.9 mg/m3 and 5,646 EU/m3 at cattle feedlots (n = 24), 2.7 mg/m3 and 1,807 EU/m3 at dairies (n = 11). 3-hydroxy fatty acid components of endotoxin varied by operation. Baseline FEV1 was lowest for dairy and grain workers. The mean cross shift change in FEV1 was -3.1% to -3.8% for all groups. The cross shift change in FVC was greatest for dairy workers (-3.8), then grain workers (-2.1%) and feedlots (-1.8). The most common symptoms reported included eye irritation (18-42%), nose irritation (18-50%), mucous (18-42%), and cough (16-30%). Symptom rates were higher among grain workers, and lowest among dairy workers. Most participants were homozygous wildtype at the TLR4 299 and 399 loci. Exposure, cross shift changes in pulmonary function, and symptoms differed by type of operation. Exposures to dust and endotoxin were extremely high in some cases. Data collection for an additional 200 workers is planned to further evaluate the relationships among respiratory outcomes and exposures in this population.
Endotoxins; Occupational-exposure; Workers; Agriculture; Agricultural-workers; Agricultural-industry; Occupational-diseases; Diseases; Respiratory-system-disorders; Inhalation-studies; Sampling; Sampling-methods; Eye-irritants; Grain-dusts; Grain-elevator-workers; Dusts; Dust-exposure
Publication Date
Document Type
Fiscal Year
NIOSH Division
Priority Area
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
Source Name
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois
Page last reviewed: August 26, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division