TITLE:
Occupational Exposure to Endotoxin in PM2.5 and Pre- and Post-Shift Lung Function in California Dairy Workers
AUTHORS:
Veronica E. Arteaga, Diane C. Mitchell, Georg E. Matt, Penelope J. E. Quintana, Joshua Schaeffer, Stephen J. Reynolds, Marc B. Schenker, Frank M. Mitloehner
KEYWORDS:
Agriculture, Particulate Matter, Concentrated Animal Feeding Operations, Respiratory Health
JOURNAL NAME:
Journal of Environmental Protection,
Vol.6 No.5,
May
26,
2015
ABSTRACT: Individual
exposures to particulate matter and endotoxin in dairies have increased as
operations have transitioned to larger herd sizes. A cross-sectional study at
13 California dairies and one non-dairy control facility was conducted to
determine associations between endotoxin concentrations measured in fine
particulate matter (PM2.5) and respiratory function in these
workers. Previous research found that dairy work was associated with acute
airway obstruction in comparison to controls. While endotoxin levels in PM2.5 have been previously reported, their effects on lung function have not been
studied among California dairy workers. This paper also examined correlations
with PM2.5 concentration, inhalable particulate matter (IPM), and
endotoxin in IPM. Personal samples collected from a total of 185 dairy workers
and 45 control workers were included in the analyses. Findings showed that
dairy facilities had higher (p 2.5 when
compared with the control facility (3.3 EU/m3, 0.6 EU/m3,
respectively). Endotoxin in PM2.5 was weakly correlated with PM2.5 concentration (r2 = 0.16, p 2 = 0.35, p 2.5 endotoxin exposure was associated with lower crossshift in forced expiratory
volume in 1 second (FEV1) and forced vital capacity (FVC) only among
taller workers (p = 0.006). This is the first study to present personal
occupational exposures to endotoxin in PM2.5 measured on Californian
dairies. Despite lower levels than in other industries, such as poultry farms,
this study suggests that some workers may be affected, and efforts should be
aimed at mitigating pollutants in order to maintain endotoxin concentrations
below recommended levels.