Exposure assessment
Environmental sampling was done with vertical elutriators
(General Metal Works, Inc., Cleveland, OH, USA) in the
various work areas during each survey period, as no personal
samplers were available for cotton dust measurements.
Airborne cotton dust and Gram negative bacteria endotoxins
were measured using methods described previously.17
Identical samplers, sampler locations, equipment, and
methods were used throughout the study. Endotoxin assays
were performed on the dust samples using the Limulus
amoebocyte lysate assay, chromogenic method.18 Production
and general conditions were stable in the cotton mills
between the first and second surveys. Geometric mean dust
exposure of the work areas ranged from a low of 0.5 mg/m3
to a high of 1.6 mg/m3 during that time. Between the second
and third surveys, the mills began to blend synthetic fibre
with cotton, and pure cotton yarn production slowed.19 The
mean dust exposure for the highest area was reduced to
1.1 mg/m3 at the third survey and to 0.5 mg/m3 at the last
survey. Environmental exposure measurements were not
strikingly different between the two cotton mills, and
endotoxin levels were moderately correlated with cotton dust
levels for all periods.19 Personal exposures to dust and
endotoxin were calculated using geometric mean levels of
environmental samples from four times multiplied by each
time period of work in specific work areas. Vertical elutriated
dust and endotoxin concentrations in the silk mill were
identified as nearly zero over the observation period.
Exposure assessment
Environmental sampling was done with vertical elutriators
(General Metal Works, Inc., Cleveland, OH, USA) in the
various work areas during each survey period, as no personal
samplers were available for cotton dust measurements.
Airborne cotton dust and Gram negative bacteria endotoxins
were measured using methods described previously.17
Identical samplers, sampler locations, equipment, and
methods were used throughout the study. Endotoxin assays
were performed on the dust samples using the Limulus
amoebocyte lysate assay, chromogenic method.18 Production
and general conditions were stable in the cotton mills
between the first and second surveys. Geometric mean dust
exposure of the work areas ranged from a low of 0.5 mg/m3
to a high of 1.6 mg/m3 during that time. Between the second
and third surveys, the mills began to blend synthetic fibre
with cotton, and pure cotton yarn production slowed.19 The
mean dust exposure for the highest area was reduced to
1.1 mg/m3 at the third survey and to 0.5 mg/m3 at the last
survey. Environmental exposure measurements were not
strikingly different between the two cotton mills, and
endotoxin levels were moderately correlated with cotton dust
levels for all periods.19 Personal exposures to dust and
endotoxin were calculated using geometric mean levels of
environmental samples from four times multiplied by each
time period of work in specific work areas. Vertical elutriated
dust and endotoxin concentrations in the silk mill were
identified as nearly zero over the observation period.
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Exposure assessment
Environmental sampling was done with vertical elutriators
(General Metal Works, Inc., Cleveland, OH, USA) in the
various work areas during each survey period, as no personal
samplers were available for cotton dust measurements.
Airborne cotton dust and Gram negative bacteria endotoxins
were measured using methods described previously.17
Identical samplers, sampler locations, equipment, and
methods were used throughout the study. Endotoxin assays
were performed on the dust samples using the Limulus
amoebocyte lysate assay, chromogenic method.18 Production
and general conditions were stable in the cotton mills
between the first and second surveys. Geometric mean dust
exposure of the work areas ranged from a low of 0.5 mg/m3
to a high of 1.6 mg/m3 during that time. Between the second
and third surveys, the mills began to blend synthetic fibre
with cotton, and pure cotton yarn production slowed.19 The
mean dust exposure for the highest area was reduced to
1.1 mg/m3 at the third survey and to 0.5 mg/m3 at the last
survey. Environmental exposure measurements were not
strikingly different between the two cotton mills, and
endotoxin levels were moderately correlated with cotton dust
levels for all periods.19 Personal exposures to dust and
endotoxin were calculated using geometric mean levels of
environmental samples from four times multiplied by each
time period of work in specific work areas. Vertical elutriated
dust and endotoxin concentrations in the silk mill were
identified as nearly zero over the observation period.
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