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Characterization of endotoxin collected on California dairies using personal and area-based sampling methods.

Garcia J; Bennett DH; Tancredi DJ; Schenker MB; Mitchell DC; Reynolds SJ; Silva R; Dooley GP; Mehaffy J; Mitloehner FM
J Occup Environ Hyg 2012 Oct; 9(10):580-591
Endotoxin, found in the cell wall of gram negative bacteria, is an important contributor to the biological activity of agriculture particulate matter (PM). We analyzed endotoxin in PM collected on 13 California dairies and from the breathing zone of 226 workers during the summer months of 2008. Two particle size fractions were measured: PM2.5 and inhalable PM. Recombinant factor C assays were used to analyze biologically active endotoxin, while gas chromatography coupled with mass spectrometry in tandem was used to quantify total lipopolysaccharide. Biologically active endotoxin concentrations in the inhalable PM size fraction from area-based samples ranged from 11-2095 EU/m3 and from 45-2061 EU/m3 for personal samples. Total endotoxin in the inhalable PM size fraction ranged from 75-10,166 pmol/m3 for area-based samples and 34-11,689 pmol/m3 for personal samples. Area-based geometric mean concentrations for biologically active endotoxin and total endotoxin in PM2.5 and inhalable PM size fractions were 3 EU/m3, 149 EU/m3, 60 pmol/m3, and 515 pmol/m3, respectively. Personal geometric mean concentrations in the inhalable PM size fraction were 334 EU/m3, and 1178 pmol/m3. Biologically active and total endotoxin concentration variation was best explained by meteorological data, wind speed, relative humidity, and dairy waste management practices. Differences in endotoxin concentration and composition were found across locations on the dairy.
Endotoxins; Dairy-products; Agriculture; Agricultural-products; Sampling; Sampling-methods; Biological-effects; Particulates; Breathing-zone; Bioassays; Gas-chromatography; Air-sampling; Mass-spectrometry; Polysaccharides; Author Keywords: 3-OHFA; agriculture; dairy; endotoxin; particulate matter
Deborah H. Bennett, Department of Public Health Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616
Publication Date
Document Type
Journal Article
Email Address
Funding Type
Cooperative Agreement; Agriculture
Fiscal Year
Identifying No.
Cooperative-Agreement-Number-U54-OH-007550; Cooperative-Agreement-Number-U50-OH-008085; B20121218D
Issue of Publication
Priority Area
Agriculture, Forestry and Fishing
Source Name
Journal of Occupational and Environmental Hygiene
Performing Organization
University of California - Davis
Page last reviewed: March 3, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division