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
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