United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S4-88/036 Jan. 1989
SERA Project Summary
Development of a High
Volume Surface Sampler for
Pesticides in Floor Dust
J. W. Roberts and M. G. Ruby
House dust and the pollutants
carried with house dust are
potentially important contributors to
exposure through the pathways of
inhalation, ingestion and skin
penetration, especially for small
children. Pesticides may be one of
the more important contaminants of
house dust
A high volume surface sampler
(HVS2) for the collection of house
dust and the semivolatile organics in
house dust has been designed and
tested. The sampler consists of an
intake nozzle, cyclone, and filter. The
position of the 'nozzle is regulated by
the static pressure in the nozzle. The
HVS2 operates at approximately 9.5
L/s (20 cfm) and can collect more
than 2 g of floor dust from a rug In an
average clean residence in less than
4 min. Over 95% of the sample Is
retained in the cyclone and would,
thus, be usable as a bulk sample for
bioassays.
The HVS2 collects approximately
30% of the dust Jess than 150 »m
from level loom and phis&e&rpets. It
collects 93.4$f W the total dust from
a smooth ba
Previous
sampling for
that semivo
dust would
filter and a
absorbent w
collect thence
test dust
ppm chl
or 100 ppm dl
of ambient
suggested
In house
on the
m (PUT)
id be necessary to
rrh house dusjt and a
fO «r 20
dleldrln and so
VlrtuaHy all the
pesticide was retained In the cyclone
or on the fitter. Although a PUF filter
does not appear to be necessary, it
can be used with the HVS2.
Several alternative sampling
methods were also studied. The
collection efficiency for fine dust of
conventional upright and canister-
type vacuum cleaners; as well as
small hand-held vacuum cleaners,
was not sufficient and use as
required here would have been
difficult or impossible.
This Project Summary was devel-
oped by EPA's Environmental Moni-
toring Systems Laboratory, Research
Triangle Park, NC, to announce key
findings of the research project that is
fully documented In a separate report
of the same title (see Project Report
ordering Information at back).
Introduction
Recent studies of human exposure to
air pollutants have increasingly
recognized the importance of pathways
other than inhalation. Ingestion of air
pollutants deposited in water or on soil is
potentially the source of a significant
portion of an individual's total pollutant
burden, especially for very young
children, with their lower body weight and
frequent hand-to-mouth activity. Dust
can be both a medium for the transfer of
pollutants from sources to people and a
medium for the accumulation of
pollutants. Failure to consider dust as a
pathway for air pollution may result in a
significant underestimation of health
risks.
Literature Review
Paniculate matter, especially fine,
carbonaceous particulate matter, has
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0.254 iig, for PCP, chlorpyrifos, and
dieldrin, respectively. If the collected
sample were 2 g, this would correspond
to 0 35 ppm, 0.57 ppm, and 0.20 ppm, in
the same order (correcting to an
assumed 100% extraction efficiency
instead of the lower, measured,
extraction efficiency).
Thus under this worst case, using the
field cleanup procedure might cause a
pristine location to be categorized as a
background situation, but would have
little if any effect on the classification of
sites with any significant amount of
pesticides present.
Alternative Sampling Methods
Several alternative test methods were
evaluated, both to determine how they
compare with the HVS2 method and to
determine if any of them should be
explored as possibly better approaches
to determining the concentration and
loading of dust on floors.
Several studies of house dust have
collected grab samples from the bags of
residents' vacuum cleaners. While this is
a quick way to collect a large number of
samples in a retrospective study, it
provides neither a consistent sampling
efficiency nor any assurance that the
samples have retained any semivolatile
materials. The principal problem with the
canister cleaner is inherent in the design:
all the air passes through the collected
sample during the entire period of
collection.
Both an upright and a canister vacuum
cleaner were tested for cleaning
efficiency using the ASTM procedures
previously described. A convertible up-
right vacuum cleaner with a power-
driven agitator was found to have a fine
materials recovery of less than 2.3% of
the test dust. A canister vacuum, without
a power-driven agitator head, collected
fine materials of 1.3% of the test dust. It
was observed that a considerable
amount of the collected sample, which
may have been a significant fraction of
the fines, could not be removed from the
bags after the test. In addition, the
power-driven agitator and nozzle of the
upright could not be cleaned without
excessive effort.
A small hand-held vacuum cleaner
gave a fine materials recovery of 4.7% of
the test dust on a level loop carpet but
only 0.6% on a plush carpet. This unit
may have been even more efficient than
the conventional vacuum cleaners in
picking up the fine material, but it did not
retain it. The fines were observed to pass
directly through the unit and exit the
exhaust as a white cloud, which was
directly into the face of the user.
Conclusions and
Recommendations
The high volume surface sampler
(HVS2) constructed by Cascade Stack
Sampling Systems (CS3) is an effective
and efficient way to collect samples of
fine surface dust. A bulk sample of more
than 2 g can be collected in about 4 min
in an average clean residence.
The static pressure in the nozzle was
found to be the best measure of the
appropriate height for the nozzle on
carpets. When operated at the defined
optimal settings, the fine materials (less
than 150 pm) collected from carpets by
the HVS2 are approximately 6% of the
total load of a standard test dust and
approximately 30% of the fine materials
in the test dust. Better than 93% of the
test dust is collected from a bare, hard
surface.
Semivolatile organic materials on the
test dusts were retained on the collected
dust. Experiments with a test dust which
contained organic material, elemental
carbon, sand, and talc found that a
polyurethane foam (PUF) absorbent filter
was not necessary for collection of the
three pesticides tested. When both
house dust and the test dust were spiked
with 10 or 20 ppm of chlorpyrifos and
dieldrin and 50 or 100 ppm of diazinon,
less than 0.1% of the pesticide was
found on the PUF filter.
The HVS2 can be used to measure
complex mixtures of metals, solids, and
organics on a variety of surfaces.
Perhaps one of the most obvious uses is
in support of studies of the health effects
of indoor air pollutants and studies of the
relative importance of pollutant pathways.
Outdoors, the sampler could be used to
measure pollutant accumulations in
potentially air-mobilized soil surfaces.
This might be useful in investigations of
the potential risks associated with fugitive
dust from hazardous waste land disposal
sites, for example.
A field test of the HVS2 would be an
important Pi9*t step for Devaluating this
instrument and the rtecommended
procedures provided in this report.
Because surface dust is: an integrated
record of the pollutants introduced into
the air above the surface', it is important
that such a field test incjpde air sampling
during a period before and between the
collection of surface samples.
The size distribution of house dust, the
size distribution of dust on the hands of
small children, and the size of particles
which pass the cyclone and are found
the HVS2 filter should all be measurec
order to more properly characterize
results obtained from the HVS2.
Although the tests reported h<
support a conclusion that no P
absorbent filter is required for so
semivolatile organics, this should
confirmed for more volatile compound:
is suspected that the same conclus
will be reached, as the more vola
compounds will also be less likely to
found in the dust.
While the tests of alternative p
cedures did not find a simple proced
which can meet the performance gc
for the HVS2, an exploration of si
methods should continue, perhaps v
the goal of finding a screening met!
which would not yield data that m
rigorous standards but could be us
inexpensively for large, prelimin;
samples.
References
Amer. Soc. Testing and Materi
(ASTM). 1987. Evaluation of carp
embedded dirt removal effective™
of household vacuum cleaners (F6i
79). In: Annual Book of AS"
Standards. Amer. Soc. Testing a
Materials, Vol. 15.07: Philadelphia,
PP.
Boubel, R. W. 1971. A high volume st;
sampler. J. Air Poll. Control As:
21:783-787
Gillette, D. A., J. Adams, A. Endo,
Smith, R. Kihl. 1980. Threshi
velocities for input of soil particles i
the air by desert soils. J. Geoph
Res. 85C:5621-5630
Krause, C., N. Englert, P. Dube. 19
Petachlorophenol containing wo
preservatives: Analyses and evaluate
In: Proceedings; Indoor Air '87, Vol
B. Seifert, H Esdorn, M. Fischer,
Ruden, J. Wegner, eds. Inst. for Wa1
Soil and Air Hygiene. Berlin, pp. 2'.
224
LaGoy, P. K. 1987. Estimated s
ingestion rates for use in ri
assessment. Risk Analysis 7:335-3!:
Lewis, R. G. and M. D. Jackson. 19i
Modification and evaluation of a hi
volume air sampler for pesticides a
other semivolatile industrial orgai
chemicals. Analytical Chem. 54:5$
594
Que-Hee, S. S., B. Peace, C. S. Cla
J. R. Boyle, R. L Bornschein, P.
Hammond. 1985. Evolution of efficu
methods to sample lead sources, SL
as house dust and hand dust, in 1
homes of children. Environ. Re
38:75-95
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J. W. Roberts and M. G. Ruby are with Engineering Plus, Seattle, WA 98122.
Nancy K. Wilson, is the EPA Project Officer (see below).
The complete report, entitled "Development of a High Volume Surface Sampler for*
Pesticides in Floor Dust," (Order No. PB 89-124 630/AS; Cost: $15.95, subject
to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield,VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
\
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S4-88/036
0000329 PS
U S SHV1R PROTECTION ftSEHCY
REGION 5 LIBRARY
230 S OiARSORK STREET .
CHICAGO IL 60604
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