EPA/600/R-97/034
                                              Jure 1997
Field and  Laboratory Evaluations of  a
          Real-Time  PAH  Analyzer
                           by
            Mukund Ramamurthi and Jane C. Chuang
                  Battelle Memorial Institute
                     505 King Avenue
                 Columbus, Ohio 43101-2693
                    Contract 68-DO-0007
                    Work Assignment 42
                       Project Officer

                      Nancy K. Wilson
                Air Exposure Research Division
             National Exposure Research Laboratory
          Research Triangle Park, North Carolina 27711
             National Exposure Research Laboratory
              Office of Research and Development
             U. S. Environmental Protection Agency
           Research Triangle Park, North Carolina 27711
                                            Printed on Recycled Paper

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                                 EPA DISCLAIMER
      The information in this document has been funded wholly or in part by the United
 States Environmental Protection Agency under Contract 68-DO-0007 to Battelle Memorial
 Institute. It has been subject to the Agency's peer and administrative review, and it has been
 approved for publication as an EPA document.  Mention of trade names or commercial
 products does not constitute endorsement or .recommendation for use.
                              BATTELLE DISCLAIMER
      This report is a work prepared for the United States Environmental Protection Agency
by Battelle Memorial Institute.  In no event shall either the United States Environmental
Protection Agency or Battelle Memorial Institute have any responsibility or liability for any
consequences of any use, misuse, inability to use, or reliance upon the information contained
herein, nor does either warrant or otherwise represent in any way the accuracy, adequacy,
efficacy, or applicability of the contents hereof.
                                         u

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                                    FOREWORD
       The mission of the National Exposure Research Laboratory (NERL) is to provide
scientific understanding, information and assessment tools that will quantify and reduce the
uncertainty in EPA's exposure and risk assessments for environmental stressors. These
stressors include chemicals, biologicals, radiation, and changes in climate, land use, and water
use.  The Laboratory's primary function is to measure, characterize, and predict human and
ecological exposure to pollutants. Exposure assessments are integral elements in the risk
assessment process used to identify populations and ecological resources at risk.  The EPA
relies increasingly on the results of quantitative risk assessments to support regulations,
particularly of chemicals in the environment. In addition, decisions on research priorities are
influenced increasingly by comparative risk assessment analysis.  The utility of the risk-based
approach, however,  depends on accurate exposure information.  Thus, the mission of NERL is
to enhance the Agency's capability for evaluating exposure of both humans and ecosystems
from a holistic perspective.

       The National Exposure Research Laboratory focuses on four major research areas:
predictive exposure modeling, exposure assessment, monitoring methods, and environmental
characterization. Underlying the entire research and technical support program of the NERL is
its continuing development of state-of-the-art modeling, monitoring,  and quality assurance
methods to assure the conduct of defensible exposure assessments with known certainty.  The
research program supports its traditional clients — Regional Offices, Regulatory Program
Officer, ORD Offices, and Research Committees — and "ORD's Core Research Program in the
areas of health risk assessment, ecological risk assessment, and risk reduction.

       Human exposure to air pollutants, including volatile compounds and semivolatile
organic compounds such as the polycyclic aromatic hydrocarbons, is an area of concern to
EPA because of their possible carcinogenicity or other toxicity. These compounds originate
from industial processes and combustion. They are present in a variety of outdoor and indoor
microenvironments.  The efforts described in this report provide an important contribution to
our capability for measuremnt and evaluation of human exposure to air toxics.
                                         Gary J. Foley
                                         Director
                                         National Exposure Research Laboratory
                                     m

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                                      ABSTRACT

      This study is a follow-up to previous work conducted at Battelle for the purpose of
 evaluating the Gossen PAS lOOOi (and the more recent Model 10021) for real-time analysis of
 particulate PAH in indoor air.  Specific tasks conducted as part of this work included further
 tests of the response of the analyzer to a number of 2- to 4-ring PAH and benzene vapors at
 high and low relative humidity levels, and an evaluation of the noise and ozone output of the
 analyzer.  The analyzer did not respond to PAH and benzene vapors in all except for two
 cases; in these two cases, it is suspected that the response observed is related to the
 adsorption of the specific PAH vapor on particle surfaces, rather than to the vapor itself.
 The noise level from the analyzer was below the NC-35 criterion except at frequencies of
 1000-3000 Hz where the levels approached the NC-40 criterion. Only small emissions of
 ozone were measured from the operation of the analyzer.

      In addition to the above tasks, a cigarette smoke generator was developed for field
 evaluations of the PAH analyzer.  Despite the inherent variability in the cigarette combustion
 process, the smoke generator  could be used in the reasonably reproducible manner to verify
 operation of a PAH analyzer in  the field.

      The effect of elevated or depressed temperature and humidity operating conditions on
 the response of the PAH analyzer was also studied. These operating conditions were not
 found to have a significant impact on the response of the analyzer to a cigarette smoke
aerosol equilibrated at the test temperature.  As a matter of research interest, it. was found
that the response of an  analyzer operated at typical indoor temperature and humidity
conditions (20"C, 40% R.H.) to a cigarette smoke test aerosol increased as a function of the
sampled air temperature.
                                          IV

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      The aerosol transmission efficiency through the PAH analyzer was also determined for
monodisperse particle sizes over the size spectrum, 0.034 - 0.32 /xm. The results suggested
that the current sampling configuration of the analyzer results in substantial aerosol losses at
small particle sizes and is not conducive to representative aerosol sampling, particularly for
particle sizes <0.10 pm.  A modified sampling configuration was developed and tested.
The modified analyzer had a transmission efficiency of >90% over the entire size spectrum.
Field tests in several indoor microenvironments did not indicate any deleterious effects on the
performance of the analyzer due to the modification in sampling configuration.

      As a continuation of work conducted previously, a systematic study of the response of
the analyzer to laboratory  generated non-PAH aerosols was also conducted. The response of
the analyzer was determined using monodisperse test aerosols of several inorganic  (sodium
chloride, ammonium sulfate) and organic substances (phthalic anhydride, di-octyl phthalate)
generated from nebulizing both water and iso-propyl alcohol solutions of these substances.
The results suggest that the response is due to contaminant(s) present in the solvent that
become deposited on the surface of the test aerosol during the droplet drying process.  The
origin and identity of the contaminants could not be determined.

      This work also included a small pilot study conducted concurrently with a PAH in
house dust study that was  the focus of a separate EPA Work Assignment.  In the pilot study,
fine particle (<2.5 /tm) PAH concentrations were sampled using an integrated filter-XAD
resin  sampling train and analyzed by an established GC/MS technique.  These concentrations
were  then compared with the average response of a PAH analyzer collocated with  the
integrated sampler.  The results obtained were consistent with those obtained in our previous
evaluation study of the PAH analyzer. The measured fine-particle PAH concentrations were
between one-fifth and two-times the PAH concentration calculated from the analyzer's
average responses asssuming a calibration constant of 3000 ng/m3/pAmp.
      This report is submitted in fulfillment of Contract No.  68-DO-0007 (WA 42) by
Battelle under the sponsorship of the U.S.  Environmental Protection Agency.  It covers the
period between June 1992 and September 1993.  Work was completed as of September 1993.

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                                  CONTENTS
Foreword	   iii
Abstract	   iv
Figures	  viii
Tables	xii
Acknowledgment  	  > ix

     1.   Introduction	    1
     2.   Conclusions	    3
     3.   Recommendations  	    5
     4.   Experimental Procedure	    6
               PAH Analyzer to 2- to 4-Ring PAH Vapors	    6
               Noise and Ozone Output of the PAH Analyzer	    8
               A Cigarette Smoke Generator For Field Evaluations
                of the PAH Analyzer	    9
               Effect of Operating Environment on PAH Analyzer Response	  16
               Aerosol Transmission Efficiency Through the PAH Analyzer
                and Modification in Sampling Configuration	  19
               PAH Analyzer Response to Non-PAH Laboratory Test Aerosols ...  24
               Field Study and Intercomparisons	  25
     5.   Results and Discussions	  28
               PAH Analyzer Response to 2- to 4-Ring PAH Vapors  	  28
               Noise and Ozone Output of the PAH Analyzer	  30
               A Cigarette Smoke Generator for Field Evaluations of
                the PAH Analyzer  	  36
               Effect of Operating Environment on PAH Analyzer Response	  42
               Aerosol Transmission Efficiency Through the PAH Analyzer
                and Modifications in Sampling Configuration	  49
               PAH Analyzer Response to Non-PAH Laboratory
                Test Aerosols  	  59
               Field Study and Intercomparisons	  64

     References	84

     Appendix A	86
                                      vn

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                                    FIGURES
Number
                                                                            Page
 4.1      Schematic of the vaporizer used to generate PAH vapors
          in the chamber	                     7

 4.2      Schematic of the locations of the PAH analyzer selected
          for O3 monitoring   	,	               JQ

 4.3      Schematic diagram of the various components of the
          cigarette smoke generator designed for field evaluations
          of the PAH analyzer	-.	              12

 4.4      Schematic of the control (front) panel of the
          cigarette smoke generator	           13

 4.5      Schematic of the test set-up used in the laboratory
          evaluations of the cigarette smoke generator 	15

 4.6      Schematic of the test set-up used in the
          temperature/humidity tests	             17

 4.7      Schematic of the monodisperse aerosol generation system
          used to evaluate the PAH analyzer	              20

 4.8       Schematic layout of the PAH analyzer showing the various
          sampling locations used in the aerosol transmission efficiency
          *•*	23

4.9       Schematic of the PAH air sampling train used in the
         pilot field study	                   26

5.1      PAH analyzer and CNC  response profiles (upper graph) during
         the addition of phenanthrene,. pyrene and fluoranthene vapors
         to  the atmospheric chamber; lower graph shows the PAH vapor
         concentration profiles 	                         29
                                      vin

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FIGURES (continued)
                                              Eags
Number

 5.2       Noise spectrum measured at a distance of 1 m from the PAH
           analyzer; also shown are the noise spectra represented by
           various noise criteria	31

 5.3        Comparison of the noise levels resulting from operation of
           the PAH (1-m distance) analyzer with typical indoor
           annoyance levels	33

 5.4       Profiles of the response of the CNC and the PAH analyzer to
           cigarette smoke generated in five consecutive runs	38

 5.5       Scatter-plot of pairs of PAH analyzer response and  CNC number
           concentrations from five consecutive cigarette burn  runs	39

 5.6       Frequency distribution of PAH analyzer responses over the
           12-15 min test intervals in each of the five cigarette runs.
           Also shown is the frequency distribution for the composite of
           data from all five runs	40

 5.7       Response of the PAH analyzer to a temperature-equilibrated
           cigarette smoke aerosol under baseline test conditions	44

 5.8       Response of the PAH analyzer to a high temperature-
           equilibrated cigarette smoke aerosol  	46

 5.9       Response of the PAH analyzer to a low temperature-
           equilibrated cigarette smoke aerosol	 47

 5.10      Comparison of the response of the PAH analyzer as a function
           of particle number concentration to cigarette smoke  aerosol at
           various sampled air temperatures	48

 5.11      Results of aerosol transmission efficiency tests conducted
           with monodisperse NaCl test aerosols  	50

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                               FIGURES (continued)
Number
                                                                           Eagfi
 5.12     Response profile as a function of time for each of the three
          PAH analyzers and the number concentration measured by
          the CNC - first test conducted in Battelle's cafeteria
          (smoking environment)	..........	„ , 53

 5.13     Response profile as a function of time for each of the three
          PAH analyzers and the number concentration measured by
          the CNC — second test conducted in Battelle's cafeteria
          (smoking environment) 	,	 55

 5,14     Response profile as a function of time for each of the three
          PAH analyzers and the number concentration measured by
          the CNC — cigarette smoking in close proximity to samplers;
          conducted subsequent to second test hi Battelle's cafeteria	 57

 5.15     Calculated increase in analyzer response as a result of the
          modification in sampling configuration; top graph  represents
          the sampling period shown in Figure 5.13; the bottom graph
          refers to the sampling period shown in Figure 5.14	 58

 5.16     Normalized PAH analyzer response to monodisperse test
          aerosols of various substances generated from nebulizing
          water and IPA solutions; also shown is surface area as a
          function of particle size	 61

 5.17     Response of the PAH analyzer during  the 24-h sampling period
          in H01RS	  . 75

 5.18     Response of the PAH analyzer during  the 24-h sampling period
          in H02RN		1	76

 5.19     Response of the PAH analyzer during  the 24-h sampling period
          in H03RN	77

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                              FIGURES (continued)
Number                                                                   Eagg

 5.20     Response of die PAH analyzer during the 24-h sampling period
          in H04RS	78

 5.21     Response of the PAH analyzer during the 24-h sampling period
          in H05RS	79

 5.22     Response of the PAH analyzer during the 24-h sampling period
          in H06RS  .	80

 5.23     Response of the PAH analyzer during the 24-h sampling period
          in H07RN	.81

 5.24     Response of the PAH analyzer during the 24-h sampling period
          in H08RN	82
                                      XI

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                                    TABLES
Number
 4.1      Summary of chamber conditions during the PAH
          vapor response tests  ....... . ..................... ......  9

 4.2      Electrostatic classifier operating parameters ..................... 21

 5.1      Ozone concentrations measured at various locations near the
          PAH analyzer and in indoor air ............................ 34

 5.2      Characteristics of the log-normal frequency distributions
          of PAH analyzer response to cigarette smoke in five
          consecutive cigarette burns ............................... 41

 5.3      Measured PAH and alkylated PAH concentrations in the air
          in home H01RS ............................... . ...... 65

 5.4      Measured PAH and alkylated PAH concentrations in the air
          in home H02RN  ..... ................................ 66

 5.5      Measured PAH and alkylated PAH concentrations in the air
          in home H03RN  ..................................... 67

 5.6      Measured PAH and alkylated PAH concentrations in the air
          in home H04RS ......................... ............. 68

 5.7      Measured PAH and alkylated PAH concentrations in the air
          in home H05RS ...................................... 69

 5.8      Measured PAH and alkylated PAH concentrations in the air
          in home H06RS ...................................... 70

 5.9      Measured PAH and alkylated PAH concentrations in the air
          in home H07RN  ..................................... 71
                                       Xll

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                               TABLES (Continued)
Number

 5.10


 5.11


 5.12
Measured PAH and alkylated PAH concentrations in the air
in home H08RN  	
Measured PAH and alkylated PAH concentrations in the
field blank sample 	
Comparison of fine particulate-bound PAH concentrations
measured from the integrated samplers and corresponding
average responses from the PAH analyzer	
72
73
                                                                              83
                                       Xlll

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                              ACKNOWLEDGEMENT
     The authors are grateful to Dr. Nancy K. Wilson, Project Manager of the U.S.
Environmental Protection Agency, for her invaluable advice during this investigation.
Technical assistance provided by David B. Davis, Patrick J. Gallahan, Donald V. Kenny,
Larry W. Miga, Jan Satola and Dr. Chester W. Spicer of Battelle is also greatly appreciated.
                                       xiv

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                                     SECTION 1
                                  INTRODUCTION
      The real-time PAH analyzer evaluated in this study was a Model PAS lOOOi
Photoelectric Aerosol Sensor manufactured by Gossen, GmbH (Erlangen, Germany) and
obtained in the United States with ancillary data acquisition software from Eco Chem
Technologies, Inc. (West Hills, CA).  Two newer versions, Model 1002i, of the PAH
analyzers were purchased from Eco Chem and were also evaluated in this study. The PAH
analyzer is based on the principle of photoelectric ionization of PAH adsorbed on the surface
of aerosol particles1"4, and is discussed in detail in an earlier Battelle study report5.

      The earlier evaluation study conducted by Battelle5 showed that the PAH analyzer is
capable of providing a real-time (<5 sec) response that is correlated with indoor fine
particulate-phase PAH (<2.5 /tm), and does not respond to 2-ring PAH vapors. The PAH
analyzer did, however, show a small but non-negligible response to non-PAH, sodium
chloride (NaCl) test aerosol.  These results suggested that the PAH analyzer had the potential
for screening and semi-quantitative measurement of human exposure to PAH in indoor and
ambient air,  and as an indicator of activities that lead to PAH  exposure. Further, the results
from the previous evaluation  study suggested the need for additional investigations to obtain a
better understanding of the nature of operation and response of the PAH analyzer.

      Accordingly, the following six major objectives were established for this follow-up
evaluation study: (1) to determine whether the PAH analyzer responds to a number of
different 2- to 4-ring PAH vapors,  (2) to measure the noise and ozone (O3) output of the
PAH analyzer, (3) to develop a cigarette smoke generator capable of use in field evaluations
of the PAH analyzer,  (4) to determine the effects of operating  environment, specifically

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temperature and humidity, on the .response of the analyzer, (5) to systematically investigate
aerosol transmission through the various components of the PAH analyzer and to evaluate if
transmission efficiency can be improved through modifications in the analyzer's sampling
flow path, (6) to further investigate the previously identified (but unexplained) response of
the analyzer to non-PAH aerosols,  and (7) to conduct a field study to compare the PAH
analyzer's response with PAH concentrations determined by air sampling followed by
GC/MS analysis.

     The above objectives were accomplished in this study in seven separate and
corresponding tasks, summarized as follows:
     Task 1:    PAH analyzer response to 2- to 4-ring PAH vapors
                Noise and ozone output of the PAH analyzer
                A cigarette smoke generator for field evaluations of the PAH analyzer
                Effect of operating environment on PAH analyzer response
                Aerosol transmission efficiency through the PAH analyzer and
                modifications in configuration
                PAH analyzer response to non-PAH laboratory test aerosols
                Field study and intercomparisons
Task 2:
Task 3:
Task 4:
Task 5:

Task 6:
Task?:

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                                     SECTION 2
                                   CONCLUSIONS
The conclusions from each task of this study are summarized as follows:

     Task 1:    The PAH analyzer does not yield a response to 2- to 4-ring PAH vapors
                including naphthalene, 1-methylnaphthalene, chloronaphthalene,
                phenanthrene, and fluoranthene. A small signal (0.008 p Amp) was
                observed for pyrene vapor at 3 ppb, when 50-60 particle/cc were also in
                the chamber.  This response, however, is probably due to the condensation
                of vapor-phase pyrene on particle surfaces.

     Task 2:    The noise level from the PAH analyzer was generally below the NC-35
                criterion, except at frequencies of 1000, 2000, and 4000 Hz where the
                noise level were close to NC-40 criterion.  The sound level from the PAH
                analyzer is between the levels in typical private homes and those typically
                recorded in large offices.  The operation of PAH analyzer did not result in
                a significant contribution to indoor O3 concentrations.

     Task 3:    The cigarette smoke generator designed and fabricated is capable of
                providing field verifications of the performance of PAH analyzers.
                Despite the inherent variability in the cigarette combustion process, the
                smoke generator elicits a reasonably characteristic frequency distribution of
                PAH  analyzer during a cigarette test.  Parameters that characterize this
                frequency distribution can then be compared with nominal ranges to verify
                operation in the field.  Additionally, the response of the analyzer was
                found to be well-correlated with the number concentration of the cigarette
                smoke.

     Task 4:    Elevated or depressed temperature and humidity operating conditions do
                not have a significant impact on the response of the PAH analyzer to a
                cigarette smoke aerosol equilibrated at the test temperature.  The response

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            of an analyzer operated at typical room conditions does appear to increase,
            relative to particle number concentration, as a function of the sampled air
            temperature. The mechanism for this increase in the response is not
            clearly established at the current time.

Task 5:     Aerosol transmission efficiency tests showed that the PAH analyzer, in its
            original design configuration, had significant aerosol losses in the sUicone
            tubing and Electrofilter, particularly at particle sizes < O.lpm in diameter
            where aerosol transmission efficiency was <70%.  A modified
            configuration, consisting of by-passing the Electrofilter and using stainless
            steel tubing  provided > 90% transmission efficiency for all test aerosols,
            ranging in monodisperse size from 0.034 - 0.32 /*m. Field trials in
            various indoor environments indicated no deleterious effects on overall
            analyzer performance as a result of the modified design configuration.
            Under typical indoor conditions in both ETS and non-ETS environments,
            an improvement in the sensitivity of the analyzer was also observed.

Task 6:     The analyzer's response to non-PAH test aerosols, normalized to aerosol
            number concentration, was proportional to particle surface area for sodium
            chloride, ammonium sulfate and phthalic anhydride aerosols generated
            from drying nebulized water solutions of the respective compounds. The
            response was reproducible and largely consistent between the different test
            aerosols.  The analyzer's corresponding response to phthalic anhydride and
            di-octyl phthalate aerosols  generated from drying nebulized iso-propyl
            alcohol (IPA) solutions was considerably smaller and did not exhibit as a
            strong a proportionality with test aerosol  surface area.  These results
            suggest that  the analyzer's response may  be related to contaminants in the
            solvents (water or IP A) used to make the nebulized solutions.  These
            contaminants may be deposited on the surface of the test aerosol when the
            solvent evaporates from the nebulized droplets, thereby causing the
            observed analyzer response.  A definite determination of the nature and
            origin of this contamination could not be achieved in this study.

Task 7:     Fine particle PAH concentrations in indoor air, measured from integrated
            sampling and GC/MS analysis, from eight homes ranged from 27 to
            120 ng/m3.  These measured PAH concentrations were within one-fifth to
            two-times of the average responses of the PAH analyzer.  The PAH
           analyzer's average response in  these tests was calculated using the
            manufacturer's suggested calibration constant of 3000 ng/m3 per pAmp of
           electrometer signal.

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                                      SECTION 3

                                RECOMMENDATIONS

      Our recommendations, based on the results obtained in this study are as follows:
(1)   The current sampling configuration employed in the PAH analyzer is not conducive to
      representative aerosol sampling. A modified sampling configuration has been
      developed and tested in this work.  The modification consists of by-passing the
      Electrofilter in the analyzer and using a stainless steel tube to replace the silicone
      tubing presently in the analyzer. Field tests have demonstrated that no deleterious
      effects arise from the modification. We recommend that the analyzer be modified for
      use in indoor particulate PAH monitoring/screening applications.  Some additional
      work may be necessitated by  the modification, including the development of a revised
      calibration factor. Establishment of revised baseline parameters for field verification
      using the cigarette smoke generator will also be necessary.


(2)   The observed response of the PAH analyzer to laboratory generated non-PAH aerosols
      may be further studied using test aerosols generated using alternative approaches that
   .   do not involve spray drying.  For example, sulfate aerosols could be generated in a
      smog chamber or (non-combustion) "smoke" could be generated from chemical
      reactions. The aerosols generated from these methods may be more similar to the
      aerosols present  in indoor air than those generated by spray drying.

(3)   We also recommend that a study be conducted to determine the indirect (+S9) and
      direct (-S9) mutagenicity of the air  sampling extracts generated from this study.  Since
      we used less than 10% of each sample extract for PAH analysis, the remaining sample
      extract can be used for bioassay analysis.  We propose to determine the residue weight
      of each sample extract and then develop a dose level for each sample extract for
      bioassay.  Each sample will be solvent exchanged into dimethylsulfide (DMSO) at a
      designated dose level and then submitted for bioassay.  The mutagenicity assays will
      then be compared with the measured PAH concentrations an the PAH analyzer's
      response.  The results will provide  us with information on whether the analyzer can be
      used as an indicator of mutagenic activity in the air.

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                                    SECTION 4
                          EXPERIMENTAL PROCEDURE
PAH ANALYZER RESPONSE TO
2- TO 4-RING PAH VAPORS
      This task involved spiking target chemicals into a 17 m3 environmental chamber,
monitoring the spiked chemical vapors in the chamber by a Trace Atmosphere Gas Analyzer
(TAGA) mass spectrometer, monitoring the particle concentration using a condensation
nucleus counter (CNC), and sampling the spiked chemical vapors by the PAH analyzer.

     The following PAH compounds were tested in the chamber experiments:  benzene,
p-dichlorobenzene, naphthalene, 1-methylnaphthalene, 1-chloronaphthalene, indene,
quinoline, phenanthrene, fluoranthene, and  pyrene. An aliquot of each of these chemicals,
other than 3- to 4-ring PAH was injected either as neat chemical or dissolved in
dichloromethane (DCM) and injected into the chamber through a heated injection port.  For
the 3- to 4-ring PAH compounds, phenanthrene, fluoranthene, and pyrene, a standard
solution of each compound was prepared in hexane, The standard solution was injected into
the chamber through a Battelle-developed vaporizer, shown schematically in Figure 4.1.
Prior to injection of each compound,  the chamber was flushed with purified air.  AADCO
zero  air was used for all of the tests.  Sampling lines connected  the chamber to (1) the
TAGA for monitoring the vapor concentration of the spiked chemicals in the chamber, (2)
the PAH analyzer for  sampling chamber  air containing the PAH vapor, and (3) a TSI
Model 3020 condensation nucleus counter (CNC) for monitoring the particle number
concentrations in the chamber.  The TSI  Model 3020 CNC has a particle size range of
sensitivity of 0.01 - 0.5

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      The TAGA was equipped with an atmospheric pressure chemical ionization (APCI)
 source, operated in the single mass spectrometry mode (MS) utilizing selected ion
 monitoring. The chamber air was sampled by the TAGA at a flow rate of IS L/min. In the
 tests with benzene, quinoline, and 2-ring PAH, the TAGA used the ambient water vapor in
 the air to form protonated water clusters which then protonated the compound of interest.
 The protonated molecular ions (M+l+) of each spiked chemical were monitored in the
 TAGA by the first quadrupole (Ql) mass analyzer, and all ions passed the second (Q2) and
 the third (Q3) «iass analyzers.

      In order to increase the sensitivity of the TAGA for the 3- to 4-ring PAH, benzene was
 used as the reagent gas and the mode of ionization was via charge exchange for these tests6.
 The molecular ions, (M+), of each spiked 3- to 4-ring PAH were monitored in the TAGA by
 the first quadrupole (Ql) mass analyzer, and all ions passed the second (Q2) and third (Q3)
 mass analyzers.  Individual standards of each PAH were prepared in hexane and injected into
 the TAGA airstream via the vaporizer described above.  The response factor (response =
 average ion counts per second/unit of concentration) for each chemical was determined from
 analyses of the standard solutions. The concentration of the spiked chemical in the chamber
 air was then determined based on the response factor. Table 4.1 summarizes the chamber
 conditions for each test.
NOISE AND OZONE OUTPUT
OF THE PAH ANALYZER
     The noise measurements were conducted in a basement of a home to obtain the lowest
possible background noise levels. Noise measurements were conducted at distances of one
and two meters from an operating PAH analyzer and flat-weighted octave-band sound
measurements were conducted at frequencies ranging from 30 - 16,000 Hz for comparisons
with the NC-35 criterion. Noise measurements using an A-weighted network were also made
to more closely reflect human audiometric responses.
                                        8

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      TABLE 4.1. SUMMARY OF CHAMBER CONDITIONS DURING THE PAH
                            VAPOR RESPONSE TESTS.
Test No.(«>
1
2
3
4
5
6
7
8
9
10
Spiked Chemical
Benzene
p-Dichlorobenzene
Naphthalene
1-Methylnaphthalene
1-Chloronaphthalene
Indene
Quinoline
Phenanthrene
Fluoranthene
Pyrene
Humidity
%
80
80
80
80
80
80
80
34
34
34
Temperature
°C
25
25
25
25
25
25
25
24
24
24
Measured
Concentration
ppb
500
300
300
300
1,000
400
40
15
1.3
3.8
   (a) The particle counts in the chamber for these tests ranged from 50-90 particles/cc.
     To determine if operation of the PAH analyzer contributes significantly to ozone (O3)
levels in air, the O3 concentration was monitored at various distances and locations around
the PAH analyzer using an U.V. Photometric O3 analyzer (Thermo Electron Instruments,
Model 49).  Figure 4.2 shows a schematic of the locations of the PAH analyzer selected for
O3 monitoring.
A CIGARETTE SMOKE GENERATOR
FOR FIELD EVALUATIONS OF THE
PAH ANALYZER
     The evaluations to be conducted of the PAH analyzer using the aerosol generator were
to be limited to verifying the general operation of a PAH analyzer unit in the field. Thus,
the aerosol generator was required to be portable, self-contained and of minimum complexity
to permit use by a field technician. The most convenient means of generating a PAH aerosol

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Figure 4.2  Schematic of the locations of the PAH analyzer selected for O, monitoring.
                                      10

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 for field evaluation of the PAH analyzer is through the combustion of a cigarette. A portable
 and self-contained cigarette smoke generator was therefore designed and fabricated in this
 task.

      Figure 4.3 is a schematic diagram of the various components of the cigarette smoke
 generator.   All internal components of the smoke generator are housed in a compact metal
 box enclosure having a size of 11 "(D) x 8"(H) x 10"(W).  Several key components are
 placed outside the box enclosure and form the control panel of the aerosol generator. These
 components include four air flow rotameter, a cigarette combustion chamber, power control
 switch and outlet  for the cigarette smoke output, as shown schematically in Figure 4.4.

      As shown in Figure 4.3, the cigarette smoke generator uses a pump (Air Cadet, Inc.
 Model 400-1911)  to provide the air flow necessary for cigarette combustion, smoke dilution
 and carrier air. Air is drawn  from outside  the box enclosure through a silica gel column
 where it is dried." The air flow output from the pump is split into two streams.  Each stream
 passes through a carbon  filter  (Balston, Inc., Model DAU) and a paniculate filter cartridge
 (Balston, Inc., Model DFU) for removal of organic vapors and particles.  One of the two
 streams is metered by a rotameter, labeled as  A in Figure 4.3, and provides carrier air at a
 nominal flow rate of 5 1pm. The other stream is further split into two streams each of which
 are metered by a rotameter. These rotameters, labeled B and C in Figure 4.3, provide
 combustion air and mixing (or dilution) air, respectively.  Air from rotameter  B at a nominal
 flow rate of 70 cc/min enters a cylindrical cigarette combustion chamber (aluminum; 114"
o.d. x 5V4" long,  placed outside the box enclosure).  Inside the combustion chamber, a
cigarette held securely in a holder bums continuously using the air flow from rotameter B.
Smoke from the burning cigarette is carried through the cigarette and out of the combustion
chamber where it  enters  a mixing chamber (aluminum; 4" o.d. x 8" long; with a removable
end cap).  In the mixing chamber, the cigarette smoke mixes with air from rotameter C
flowing at a nominal rate of 2.5 1pm.
                                         11

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                             AIR IN
                  SUCA
                   GB.
         CARBON   PARTCULATE
                                                       0-100 CC/MIN
                                                       ROTAMETER
                                                              CAPSIZE
                                                                         CIGARETTE COMBUSTION
                                                                              CHAMBER
                 0-5LPM
                 ROTAMETER
               =>   (A)
BOX ENCLOSURE

ROTAMETTERS
(A) Carrier Air; 0 - 5 Ipm; set to 5 Ipm nominal
(B) Cigarette Smoke Combustion Air; 0 -100 cc/min; set to 70 cc/min nominal
(C) Mixing Air; 0 - 5 Ipm; set to 2.5 Ipm nominal
(D) Calibration Smoke Feed; 0-50 cc/min; set to 25 cc/min nominal
    Figure 4.3.  Schematic diagram of the various components of the cigarette smote
               generator designed for field evaluations of the PAH analyzer.
                                            12

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                CARRIER   CIGARETTE
                  AIR
                            AIR
CALBRAT1ON   MXING
  SMOKE      AIR
   FEED
                                            CIGARETTE
                                           COMBUSTION
                                            CHAMBER
Figure 4.4.  Schematic of the control (front) panel of the cigarette smoke generator.
                                        13

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      The diluted cigarette smoke exits the mixing chamber through a single port with two
 flow paths. The major flow path passes through an adjustable ball valve and a HEP A
 capsule filter (Gelman, Inc., Model 12144) where the cigarette smoke is filtered before the
 air flow is vented.  The other flow path passes through rotameter D at a nominal flow late of
 25 cc/min.  This small fraction of cigarette smoke from the mixing chamber enters the
 carrier flow stream from rotameter A.  Carrier air flow mixed with cigarette  smoke aerosol
 is then available for sampling by the PAH analyzer.  Other particle sensing instruments such
 as a Condensation Nucleus Counter (CNC) can also sample the cigarette smoke output.

      A series of laboratory tests was conducted to evaluate the cigarette smoke generator
 and to determine an optimum set of operating parameters.  The nominal rotameter flow rates
 shown in Figure 4.3 were derived from these tests.

      The response  of the PAH analyzer to cigarette smoke is determined largely by the
 concentration of cigarette smoke in the air sampled by the PAH analyzer. The cigarette
 smoke concentration in the carrier air is a function of the four rotameter flow settings. A
 PAH  analyzer response of 0.3-1 pA was established as the design target for field evaluation
 purposes.  The cigarette smoke concentration required for this range Of PAH analyzer
 response was men obtained by selecting an appropriate combination of the four air flow
 rates.

      The test set-up used in the laboratory evaluations is shown schematically in Figure 4.5.
 Cigarette smoke from the generator was sampled simultaneously by the PAH analyzer and a
TSI Model 3020 CNC. The response of both instruments was recorded using a datalogger
 (Rustrak Inc., Model Ranger II) at 10 second intervals for the duration of each cigarette
bum.  A single cigarette burn ran for a period  of about 12-15 minutes.

      Research cigarettes from the University of Kentucky were used in the tests.  A  few
runs were also conducted using a commercial brand (BASIC) of cigarettes.  However, the
smoke particle concentrations from the combustion of commercial cigarettes were found to be
                                         14

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                              GOSSEN
                              PAS 10001
          CIGARETTE
           SMOKE
         GENERATOR
-5.0 Ipm
                                  -3 Ipm
                  _v. Excess
Vent
                                  -0.3 Ipm
                                TSI
                              3020 CNC
Figure 4.5  Schematic of the test set-up used in the laboratory evaluations of the
                         cigarette smote generator.
                                    15

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 significantly more variable than those from the research cigarettes.  Specifically, high particle
 number concentration peaks of short time duration were frequently observed from the
 commercial cigarettes; such peaks were relatively infrequent from the research cigarettes.

      A series of tests were conducted using the cigarette smoke generator.  Initially, the net
 charge on the cigarette smoke aerosol was determined using the electrometer in the PAH
 analyzer (Electrofilter and UV lamp OFF; see Chuang and Ramamurthi, 1993).
 Subsequently,- the response of a fully-functional PAH analyzer to test aerosols generated
 using the smoke generator was determined in a series of repetitive tests.
 EFFECT OF OPERATING ENVIRONMENT
 ON PAH ANALYZER RESPONSE
      The temperature/humidity tests were conducted in a systematic manner using the
 cigarette smoke generator set-up described above and a laboratory environmental test
 chamber. A schematic diagram of the experimental test set-up used in the
 temperature/humidity tests is shown in Figure 4.6.  The environmental test chamber was
 maintained at three different conditions during the tests:  20*C, 50% R.H.; 45*C, 30%
 R.H.; and 3"C, 80% R.H. The aerosol output of the cigarette smoke generator was
 transported into the chamber where it first passed through a cylindrical tube  (14 in. long, 1
 in. i.d.), half-filled with silica gel,  lying on its side in the chamber.  As the cigarette smoke
 aerosol flow passed over the silica gel it was de-humidified to prevent condensation of water
 vapor in the transport lines.  Note that although the carrier air used in the cigarette smoke
 generator is dried by passage through a silica gel column prior to use, water vapor absorbed
 in the tobacco can enter the flow stream as a result of the combustion of the cigarette.

     The de-humidified aerosol flow then passed through a 12 ft. long copper coil for
 temperature equilibration. Upon exiting the copper coil the aerosol flow was split into three
portions, one was drawn  by the PAH analyzer, the other  by a TSI Model 3020 Condensation
 Nucleus Counter (CNC), and the third consisting of excess air was exhausted in a ventilated

                                        16

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         Cigarette Smoke
           Generator
Exhaust
                      Insulated lines
                        Gossen PAS
                      (outside chamber;
                      room temperature)
                                                      Environmental Test Chamber
Controlled temperature and humidity
                                                 Silica gel drying
                                                      tube
                                               Datalogger
               Copper
                 coil
                                                             i   Gossen PAS
                                                             * (inside chamber)
     Figure 4.6 Schematic of the test set-up used in the temperature/humidity tests.
                                            17

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 hood. The CNC was always operated outside the chamber, while the PAH analyzer was
 operated either inside or outside the chamber for comparative analyses. All aerosol flow
 transport lines outside the chamber to the CNC and PAH analyzer (the latter when operated
 outside the chamber) were insulated with polyurethane foam tube-sheathing. The residence
 time of the cigarette smoke aerosol inside the chamber was on the order of about 2 seconds.
 A datalogger was used to record the data collected from the tests, consisting of the particle
 concentration (CNC) and analyzer signal (PAH analyzer) readings recorded at 10 second
 intervals over run durations of 10-15 minutes each.  Each run corresponded to the duration
 of a single cigarette burn in the smoke generator and 2-3 runs (or burns) were conducted in
 each of the test configurations described below.

      Three sets of experiments were conducted :
 Baseline Tests:
      The base-line response of the PAH analyzer and CNC to de-humidified cigarette smoke
 aerosol was determined by equilibrating the aerosol at a temperature of 20"C.  The PAH
 analyzer was also equilibrated by operation inside the chamber at 20 *C and 50% R.H. for ~2
 hours prior to the tests.
Low-Temperature Tests:
     The low temperature tests consisted of two parts:  In the first, the PAH analyzer and
the CNC were operated outside the test chamber at room temperature (~25'C, 60% R.H.) and
sampled smoke aerosol equilibrated at a temperature of 3*C.  In the second part, the PAH
analyzer was placed inside the chamber at 3*C and 80% R.H. and operated for a period of
about 2 hours before sampling the low temperature-equilibrated cigarette smoke aerosol.

High-Temperature Tests:
     The high temperature tests were conducted using the two-part procedure described
above for the low temperature tests. The cigarette smoke  aerosol was equilibrated at a
temperature of 45 *C.  When operated inside the chamber, the PAH analyzer was equilibrated
                                        18

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 at 45 *C and 30% R.H. for about 2 hours prior to sampling the high temperature-equilibrated
 aerosol.
 AEROSOL TRANSMISSION EFFICIENCY
 THROUGH THE PAH ANALYZER AND
 MODIFICATIONS IN SAMPLING CONFIGURATION
      Aerosol transmission efficiency tests were conducted using monodisperse sodium
 chloride (NaCl) test aerosols.  A schematic diagram of the experimental test set-up is shown
 in Figure 4.7. A polydisperse NaCl aerosol was generated using a constant output atomizer7
 and a concentration of 1.0 g NaCl//  in water.  The polydisperse aerosol generated from the
 atomizer has a log-normal droplet distribution, with dm~ 0.65 fim and 
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                                            £
                                            I:


                                            I
                                            2
                                           i
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20

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       TABLE 4.2 ELECTROSTATIC CLASSIFIER OPERATING PARAMETERS
Folydisperse and
Monodisperse Flow
Rates (1pm)
4.0
4.0
4.0
4.0
4.0
Sheath and
Excess Flow
Rates (Ipm)
20
20
20
20
10
Collector Rod
Voltage
(V)
467
12%
3600
10000
10000
Monodisperse
Particle Size
G*m)
0.034
0.06
0.11
0.20
0.32
      Prior to conducting aerosol transmission efficiency tests, the performance of the EC
was verified using sub-micron Poly-Styrene Latex (PSL) test aerosols of sizes 0.06 /*m and
0.10 urn.  The PSL aerosols were generated by nebulizing suspensions of monodisperse PSL
spheres in water.  Performance verification experiments consisted of verifying that the
theoretically expected set of EC operating conditions (flows, collector rod voltage) indeed
resulted in the presence of the PSL test aerosol in the monodisperse flow output from the
EC. Presence of PSL aerosol in the monodisperse flow output was detected using the TSI
Model 3020 Condensation Nucleus Counter (CNC).
      In addition to these verification experiments, a series of experiments was also
conducted to calibrate the CNC.  The CNC requires periodic calibration with a monodisperse
test aerosol because of possible degradation of the photodetector and optics (TSI Model 3020
Instruction Manual). To calibrate the CNC, the test set-up in Figure 4.7 was used to
generate monodisperse NaCl test aerosols of 0.05 /xm diameter.  The singly charged
monodisperse aerosol output of the EC was sampled by the CNC and an Aerosol
Electrometer (AE) (TSI  Model 3068).  Using different amounts of dilution air,  monodisperse
particle concentrations in the range 1,000 - 225,000 particles/cm3 were generated.  The AE
is a primary standard and its current (pA) readout allowed calculation of the particle number
concentration based on the flow rate  through the electrometer. The CNC was accordingly

                                        21

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 calibrated by adjusting the span and zero potentiometers to provide a number concentration
 display consistent with the calculated concentration from the AE.  Corrections for
 interference from multiply charged particles were included in performing the CNC
 calibration.

      The calibrated CNC was then used in tests to determine the aerosol transmission
 efficiency of the PAH analyzer.  As indicated in the schematic in Figure 4.7, the
 monodisperse aerosol output of the EC was neutralized, diluted as necessary and passed into
 a mixing chamber.  The neutralized test aerosol was then sampled out of the chamber and
 through the PAH analyzer using a pump external to the analyzer.  The internal PAH analyzer
 pump was not utilized in the tests because of its inability to maintain a constant flow under
 the conditions of a positive pressure of 4-10 cm. H2O in the mixing chamber.  A number of
 aerosol transmission tests were also conducted using singly-charged aerosols;  the mixing
 chamber was not employed in these tests to minimize particle losses.

      Flow through the PAH analyzer was maintained at 4.01pm using a metering valve and
 was continuously monitored using a mass flowmeter.  The CNC sampled the aerosol either
 immediately upstream of the PAH analyzer inlet or from a specific sampling location inside
 the PAH analyzer.  Care was taken to use matched lengths of tubing to connect the CNC to
 the two sampling locations; all tube lengths were kept to a minimum and metal tubing was
 used throughout the test set-up.  Figure 4.8 is a schematic of the sampling locations within
 the PAH analyzer used in the aerosol transmission  efficiency tests.

     Modifications in sampling configuration were made in the PAH analyzer as a result of
the findings of the aerosol transmission efficiency tests. Specifically, the Electrofilter (EF)
in the PAH analyzer was by-passed and stainless steel  tubing was used to connect the inlet of
the analyzer directly to the inlet of the UV ionization chamber. A series of tests were then
conducted with  the modified analyzer,  with the following objectives:

     Test 1:      Determine aerosol transmission efficiency through  the modified analyzer.
                                          22

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         Inlet
             Electrically
             isolated
             Connector
                               ! ON/OFF!
                                                      PAH ANALYZER
                                      _T
                         Etectrofilter(ESPh|-+465V
Photo-ionization\
chamber; UV    \uvump	;oN/OFFj
                                  Electrometer
                                                           Pump
                                    Response
Figure 4.8  Schematic layout of the PAH analyzer showing the various sampling
           locations used in the aerosol transmission efficiency tests.
                                      23

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      Test 2:     Determine if the modified PAH analyzer is subject to errors from the
                 presence of non-electrically neural aerosols in typical indoor
                 microenvironments.
      Test 3:     Compare the response of the modified PAH analyzer to a collocated
                 original, un-modified PAH analyzer.
 PAH ANALYZER RESPONSE TO NON-PAH
 LABORATORY TEST AEROSOLS
      The tests conducted in this follow-up study of the response of the PAH analyzer to
laboratory-generated test aerosols consisted of a more detailed and systematic version of
similar experiments conducted in the previous evaluation study5. Specifically, the
monodisperse aerosol generation scheme described in Section 4.5 was used to generate test
aerosols of various substances.  The response of the PAH analyzer a function of
monodisperse particle size and number concentration was then determined using the test
aerosols.

      Test aerosols were generated from the following solutions:
      •    Sodium chloride in water
      •    Ammonium sulfate in water
      •    Phthalic anhydride in water
      •    Phthalic anhydride in iso-propyl alcohol
      •    Di-octyl phthalate in iso-propyl alcohol

The five monodisperse aerosol sizes shown in Table  4.2 were used in the experiments with
each test aerosol.
                                        24

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 FIELD STUDY AND
 INTERCOMPARISONS
      A small pilot field study was conducted in eight houses in Columbus, Ohio during
 April, 1993. Four smokers' houses and four non-smokers' houses were selected.  The
 selection process of the sample houses was conducted as part of a separate and concurrent
 EPA study (Work Assignment 35)9.  Overall, indoor air in each house was sampled as part
 of this study (Work Assignment 42) and house dust, entryway soil, pathway soil, and
 foundation soil were sampled under the other study (Work Assignment 35).

      An integrated indoor air sampler10 and the PAH analyzer were placed in parallel in
 either the living room or family room of each house. The PAH analyzer was set up with its
 inlet at about the same height and about 1 foot from the inlet of the indoor air sampler.  The
 sampling train for the indoor sampler consisted of the following components (listed in the
 order of air flow),  impactor-denuder-quartz fiber filter and XAD-2 trap, which was designed
 to collect fine paniculate (<2.5 /*m) PAH in the sampled air stream.  Figure  4.9 illustrates
 the sampling train schematically.  The impactor used in the train was an URG, Inc. Model
 200-30 impactor with a characteristic aerodynamic particle cut-off diameter of 2.5 pm
 (dp-50 percent collection efficiency) at a flowrate of 20 L/min11. The impactor was
 operated with the impaction frit coated with silicone grease and removed all particles greater
 than 2.5 ftm in aerodynamic diameter from the flow stream.
      A Battelle Medium Volume Compound Annular Denuder (MVCAD)12, coated with
silicone grease using a procedure described previously13, was placed downstream of the
impactor to remove vapor-phase PAH from the air stream sampled.  The MVCAD has been
demonstrated in previous studies to be highly efficient in removing vapor-phase PAH from
indoor air at the flow rates employed, while maintaining essentially 100% transmission of
fine particles in the dp <2.5 urn size range13.  The fine paniculate PAH penetrating the
denuder was collected on a quartz fiber filter, with the XAD-2 resin trap downstream of the
filter used to trap PAH volatilized from paniculate PAH collected on the filter during the

                                        25

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                              ami
                                              URG, Inc. 2.5 \an cut
                                              impactor (silicone coated
                                              impaction plate)
                                              Compound
                                              Annular Denuder
                                             -(Battelle MVCAD)
                                              Silicone-coated for
                                              PAH vapor removal
Quartz Fiber
Filter (47 mm)
                                              XAD-2 resin
                                              trap
                     Fine Particle-Bound (<2.5 pm) PAH:
                     Combined analysis of filter arid XAO trap
                     (XAD trap for PAH volatilized from particles
                     collected on filter)
Figure 4.9  Schematic of the PAH air sampling train used in the pilot field study.
                                        26

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sampling period. Prior to sampling, the clean filter and clean XAD-2 trap, the impactor, and
the MVCAD were prepared by the respective methods developed by Battelle11'12.  The
sampling flow rate through the sampling train was controlled at 20.0 ± 0.21pm using a
pump and a metering valve and was monitored continuously by an in-line mass flow meter.
Indoor air was sampled for a period of 24 hours at each house.

      After 24-h sampling, the filter and XAD-2 trap was removed from the train and sent
back to Battelle for analysis.  The corresponding filter and XAD-2 samples were combined
and extracted with DCM by the Soxhlet technique.  The DCM extract was concentrated by
Kuderna-Danish (K-D) evaporation, and analyzed by gas chromatography/mass spectrometry
(GC/MS) for 2- to 7-ring PAH and their alkylated PAH.

      A Finnigan TSQ-45 GC/MS/MS operated in GC/MS mode and an INCOS 2300 data
system were employed. The MS was operated in selected ion monitoring (SIM) mode.
Peaks monitored were the molecular ion peaks and characteristic fragmentation ion peaks.
The GC column was a fused silica capillary column (30 m x 0.25 mm; 0.25 pm film
thickness, Supelco). The GC temperature was held  at 70°C for 2 min, programmed to
290°C at 8°C/min.  Each sample extract was analyzed twice — once for parent PAH analysis
and again for alkylated PAH analysis.  Identification of the target analyte was based on the
GC retention time relative to the corresponding internal standards (phenanthrene-d10 and
9-phenylanthracene).  Quantification of target analyte was based on comparisons of the
respective integrated ion  current response of the target ion  with that of the corresponding
internal standard, with the average response factor for each target analyte generated from
standard analyses14.  Quantification of alkylated PAH was based on the average response
factor of the respective parent PAH.
                                         27

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                                    SECTIONS
                            RESULTS AND DISCUSSION

 PAH ANALYZER RESPONSE TO
 2- TO 4-RING PAH VAPORS
       The objective of this task was to verify that the PAH analyzer does not respond to
 PAH vapors as reported by Eco Chem Technologies, Inc. In our previous evaluation study5,
 we demonstrated that the PAH analyzer did not respond to benzene and 2-ring PAH vapor at
 room temperature (25°C)  and low humidity conditions (9%  R.H.).  In the current study,
 tests were conducted for ten chemicals including benzene, and 2- to 4-ring PAH (see
 Table 4.1) at higher chamber humidity (34 to 80% R.H.) and room temperature (24-25°C)
 conditions.

       The tests conducted in this  study also showed no PAH analyzer response to
 vapor-phase PAH in all except two cases.  In one case  where a response was observed
 (~0.2 p Amp) for indene, a substantial particle concentration of -50,000 particles/cc was
 measured in the chamber suggesting that the observed PAH analyzer response was due to the
 adsorption of vapor-phase indene onto particle surfaces. The particle formation observed
 was traced to the polymerization of the aged indene liquid used in the test, as described in
 the Merck Index.
      In the other case, a small signal (0.008 p Amp) was observed at a pyrene vapor
concentration of 3.8 ppb, with a corresponding particle concentration in the chamber of 60-
75 particles/cm3. A detailed presentation of the results of the latter test, which also included
the addition of phenanthrene and fluoranthene vapors, is shown in Figure 5.1.  The upper
graph in Figure 5.1 shows the response of the PAH analyzer and the CNC to air sampled

                                        28

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PAH Analyzer Response (pA)


        g     S     S
PAH Vapor Concentration from TAGA

             (ppb)
                                                               §
                                                                   1
                                                                   8
                                                               o
                                                              . o
                                                              f o
                                             (qdd)

                                VOV1 UJQJJ uoiiEJiuaouoo jodeA HVd
                                 29

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from the test chamber as a function of time after the addition of phenanthrene, pyrene
and fluoranthene vapors. The lower graph in the figure shows the vapor concentration of
each of these vapors in the chamber as measured by the TAGA.

       The results in Figure 5.1 clearly demonstrate that no response was observed from the
PAH analyzer to air containing —10 ppb of phenanthrene vapor.  However, in the next phase
of the test, when pyrene vapor was added to the chamber, a very small but clearly
observable response was observed from the PAH analyzer.  The response profile as a
function of time corresponding very closely with the pyrene vapor concentration profile, and
exhibited a similar decay as the concentration profile.  This small response is likely a result
of the condensation of pyrene on existing particles in the chamber because of its low
saturation  vapor pressure. About 60-75 particles/cm3 were present in the chamber during the
tests.  The addition to the chamber, in the final phase of the test, of fluoranthene vapor did
not elicit a response from the PAH analyzer at levels up  to 1.5-2.0 ppb of the PAH vapor.

       In summary, the PAH analyzer did not yield any  response  for vapors of benzene, and
2- to 4-ring PAH at room temperature under both low and high humidity  (9 to 80% relative
humidity).
NOISE AND OZONE OUTPUT OF
THE PAH ANALYZER
      The objective of this task was to determine the noise and ozone output from the
operation of the PAH analyzer. Figure 5.2 shows the noise levels at various frequencies
measured at  a distance of one meter from the PAH analyzer and the corresponding levels
represented by the NC-30, NC-40, and NC-50 criteria.  As shown in Figure 4.1, the noise
levels from the PAH analyzer were generally below the NC-35 criterion except at
frequencies of 1,000, 2,000, and 4,000 Hz where the noise levels were close to the NC-40
criterion. The increased sound levels at these frequencies are most likely due to the
high-pitched sound emitted by  the mini-pump in the PAH analyzer.  The measured sound

                                         30

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               Noise Spectrum for
                    PAH Analyzer
                    100       1000     10000

                     Frequency (Hz)
                100000
                   NO 30

                   IMC-40
NIC-50
PAH Analyzer
Figure 5.2 Noise spectrum measured at a distance of 1 m from the PAH analyzer; also
       shown are the noise spectra represented by various noise criteria.
                          31

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levels did not drop off significantly at a distance of two meters from the analyzer compared
with the measured level at a distance on one meter.

       Figure 5.3 shows a comparison of the A-weighted noise levels measured at a distance
          ^  » -  -  ••'  -,•!-» *  . j_  *• k- •*># it-:.-i. •**.'.  .--.-.,»*" ,» j, '„ '•". -U ,_#?.- -•-.: >* t .':-;:>- ','^'ti- ^i*., "' *w»V s^-A-Ml^l'i",* V.-V, KfW^,, » K;---*••, "vi^i ,*"'* t*
of one meter from the PAH analyzer and  the corresponding levels typically present in various
           " .   *      ---*•**  ,-»* .[Li » -i-- -•,..  -u-^i »-,j*.  us. A *C1v .. ... .Wkji* -•>,. .^,.^ ;.*,.-,,*< i'.  4.'  1J » *- ,,~*,i^V.i.- «f *-• "- '.V ^7'A*»,i-w ' i . » ' -,7* T -t . ,, L-» . ,
indoor micrpenvironments.  The sound level from the operation of the PAH analyzer  is in
between that found in typical private homes and large offices.
         — . w-   - -_ -*•  •*.. -"—-' i»* .- , . in, A, j. - . _„,„: ,.j.-..» .„ Jf-,.  <«, S-»B, ,»i«^kj*<;;r ;»,.	,_,, ,,.;.:

       Ozone (O3) concentrations were also monitored at various locations from the PAH
        . - '- , • -  ^ ,. •"  •«,-.,.!. ;. .,.».,«.  f,  -  *r u, iff »!'** *nr.». *«, .,,*h, .,.«-. B^i >* .*,. w<  «**!„ n -&»H~ -JL-^WH, r< f JiL-..^^Vf-^Js.-* - i „: .*, ,„ ^ -!li,,.', *-»» (r»ft '.„ :, ~fl^ ,
analyzer when the analyzer was in pperatipn (see Figure 4.2).  Table 5.1 summarizes the  §3
    i                   i             i         «      -i        .          w                    *"• ^
measured concentrations at these various locations. As shown in Table 5.1, the operation of
        S'jt  *  . *V r „-.,-.'.,  .•*...*..«. ,„«„„-.,..• J> =™_ « a. n.,** .j.m.J "«*««*.* •»,« 1 JS'*>'   * fc' KWi'l-H,  "' s ** A!jM  *.*»•>. ' iV  « .r. ^. iff 6J*,i.".11 ».. JT^, ..-. ^v.' . • . ' ",*i "i '
the PAH analyzer did yield slightly higher O3 cpneenfrations ([1^-180 ppb), than  tiipje
typically found indoor air, at location $.  ]Lpcatipn 6  is located at thf upper left corner of the
instrument (see Figure 4.2), and in close proMmity to tiie analyzer's pump outlet.  Ho,weyer,
the O3 concentrations decreased to typical indoor levels (—20 ppb) at distance of  1  inch
      **   -    ... ~ ..*— -- -  -^ .„-.-„...-„..„ 4. -  .Jf.'^M,,,  * .._., *j^ „ ,,,« . ^iu.^ > •"  vu, ^ rrJCT., V it.,, u-hrf^^A/.j.-..^!.  C*  IT. ...ivfe^,
above location 6, suggesting that the overall ozone emission ratg is npt yery significant. The
O3 concentrations measured at other locations were generally within  thp range of ipdopr O3
levels.  Therefore, we conclude that the pperatipn of the PAH analyzer in indoor
environments will not contribute significantly to indoor O3 levels.
                                             32

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       Auditoria
   Private Home
    PAH Monitor
    Large Office
                  COMPARISON OF PAH

                  MONITOR vs INDOOR

                   NOISE ANNOYANCE

                         LEVELS
                             A-weighted
                             Sound Level
                               (dB)
Figure 5.3 Comparison of the noise levels resulting from operation of the PAH
       (1-m distance) analyzer with typical indoor annoyance levels.
                           33

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TABLE 5.1. OZONE CONCENTRATIONS MEASURED AT VARIOUS
 LOCATIONS NEAR THE PAH ANALYZER AND IN INDOOR AIR
Location
Room air 2 ft from case
Instrument turned on
12 inches from case
Position #1
To position "#2
To position #3
To position #4
To position #5
Back to position #4
To position #6
To position #7
To 12 inches from case
Turned instrument around
12 inches from case
To position #1
To position #2
To position #3
To position #4
To position #5
To position #6
To position #7 -
To position #8
Back to position #6
Moved sampling line closer to opening in case
Concentration, ppb
9.2
9.8
9.7
40,3
13.6
15.0
159.2
38.7
98.0
31.3
9.4
11.3
15.9
20.9
18.0
23.1
101.4
153.3
160.9
29.1
38.4
185.5
                                               (continued)
                        34

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                              TABLE 5.1.  (continued)
                  Location
Concentration, ppb
Turned off hoods and air conditioning to stop
air movement in room
6 inches from case opposite top
6 inches above top and side
To 3 niches
To 1 inch
1 inch above and 1 inch from side
Below and under 1/2 inch
To position #6 under lip
Hoods and air conditioning back on
To position #6
To 1 inch above position #6
To room  air 2 feet from case
To another part of room away from instrument

To outside air
          179.8
          21.3
          24.9
          33.9
          42.9
          35.7
          19.2
          116.6
          118.5
          189.0
          22.2
          20.3

          21.0
          53.3
                                        35

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 A CIGARETTE SMOKE GENERATOR FOR
 HELD EVALUATIONS OF THE PAH ANALYZER

       The purpose of this task was to design, fabricate and test a cigarette smoke generator
 capable of use in field evaluations of the Gossen PAS Model 1000L A standard protocol
 describing the application of the aerosol generator for field evaluation of the PAH analyzer
 was also developed. The evaluations to be conducted of the PAH analyzer using the aerosol
 generator were to be limited to verifying the general operation of a PAH analyzer unit in the
 field. Thus, the aerosol generator was required to be portable, self-contained and of
 minimum complexity to permit use by a field technician.

       Since the PAH analyzer could potentially respond to an electrically charged (net
 charged) aerosol as well as particulate PAH, an initial series of exploratory tests was
 conducted with the output of the smoke generator.  In the first series of tests, the PAH
 analyzer was operated in a mode where the Electrofilter and UV lamp were both turned off
 (see Chuang and Ramamurthi, 1993 for details).  In this mode, the PAH analyzer is
 essentially an  aerosol electrometer and measures  the net charge on the sampled aerosol.  The
 response of the PAH analyzer in this mode to sampled cigarette smoke aerosol was at all
 times within 0.000 ± 0.005 pA. This result indicates that the cigarette smoke output from
 the smoke generator is essentially net neutral in charge.  In a second series of tests, the
 electrofilter was turned on but the UV lamp remained off.  In this mode, some fraction of
 the charged particles are removed by the electrofilter but no photoemission can occur within
 the PAH analyzer.  Again, the response of the PAH analyzer electrometer was within 0.000
 ± 0.005 pA at all times.  This result indicates that the operation of the PAH analyzer
electrofilter does not cause a net charge to form in the sampled cigarette smoke aerosol.  The
zero response of the PAH analyzer in both these  test modes confirmed the acceptability of
the smoke output for evaluating the response of the PAH analyzer to particulate PAH.
                                        36

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        Cigarette smoke from the smoke generator was then used in a series of tests with the
 PAH analyzer in its normal operating mode.  The results of these runs, conducted using the
 optimized set of flow rates, are presented in Figure 5.4. The figure shows the responses of
 the CNC and PAH analyzer in five consecutive runs using research cigarettes burnt in the
 smoke generator.  Figure 5.4 reveals that the cigarette combustion process results in a time-
 varying smoke concentration.  This variability in the smoke concentration is to a large extent
 a result of the inherently uneven process of cigarette combustion.  The cigarette bum rate
 may be affected by a number of parameters such as tobacco packing density and humidity.
 In addition, the use of rotameters limits the degree of control on the air flows through the
 smoke generator.  However, rotameters were the only practical option available to us in
 developing an economical and portable smoke generator. Thus, the degree of stability in
 cigarette smoke concentration shown in Figure 5.4  is probably the best that can be achieved
 without adding to the complexity of the smoke generator or its operating requirements.

       The results in Figure 5.4  also show that the response of the PAH analyzer is well
 correlated with the number concentration indicated by the CNC. Figure 5.5 is a scatter-plot
 of pairs of PAH analyzer response and CNC particle concentration data from the five runs
 discussed earlier. The best-fit, log-linear correlation between the two instrument responses is
 indicated by the equation shown in Figure 5.5. The fit to the data of the log-linear
 relationship and the calculated  correlation coefficient are also shown in the figure.

       Field evaluations of the PAH analyzer are likely to be conducted without the
 availability of a CNC to measure the number concentration  of the cigarette smoke.
Therefore, an alternative means of analyzing the PAH analyzer response data was also
 sought. Figure 5.6 shows a frequency distribution of PAH  analyzer responses over each of
the 12-15 min. test intervals in the five cigarette runs. The frequency distribution is shown
in Figure 5.6 using 10 response intervals of equal size on a logarithmic scale spanning the
range 0.01-2.0 pA.  The frequency distributions  for the five separate runs shown  in
Figure 5.6 reveal that the responses of the PAH  analyzer are log-normally distributed within
each run.  Also shown in Figure 5-6 is the frequency distribution of data set deriving from
                                          37

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Run 1

	 Run2

	 Run 3
	 Run 4 "~
""'"•'•'" Run 5
12000 -\
  Figure 5.4.  Profiles of the response of the CNC and the PAH analyzer to cigarette smoke
                           generated in five consecutive runs.
                                          38

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       10
        1
IS
I
      0.1-
     0.01
                                       1.46
      PAS [pA]» 1.38E-06* CNC Iparticles/cm*3]
                                                        Tests conducted at
                                                        room temperature: 25*C
       1000
       10000
Number Concentration
   CNC Reponse
   (particles/cmA3)
100000
Figure 5.5.  Scatter-plot of pairs of PAH analyzer response and CNC number concentrations
                       from five consecutive cigarette burn runs.
                                         39

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                                                             	RunS
                                                                 Composite
                 0.013  0.022 0.038 0.064 0.11  0.18  I 0.31   0.53  030  1.53   (mid-points)
                                       PAS Response JpA]
                                   Intervals shown on a log-scale
  Figure 5.6. Frequency distribution of PAH analyzer responses over the 12-15 min test
intervals in each of the five cigarette runs.  Also shown is the frequency distribution for the
                          composite of data from all five runs.
                                           40

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compositing the data from the five individual runs. The composite frequency distribution is
also seen to have a log-normal characteristic. This characteristic feature of the PAH
analyzer response may be used to verify the operation of a PAH analyzer tested in the field
using the smoke generator.

      A log-normal frequency distribution is well characterized by a geometric mean
response (r_) and geometric standard deviation (
-------
       Table 5.2 indicates that the responses of the PAH analyzer in the multiple cigarette
 smoke tests are characterized by geometric mean and standard deviation parameters that are
 consistent within a narrow range of values. This result suggests that PAH analyzer responses
 obtained in field evaluations with the smoke generator can be characterized by their
 geometric distribution parameters and compared with the parameter ranges shown in
 Table 5.2 to verify proper operation.  A standard protocol for operating and maintaining the
 smoke generator is provided in Appendix A of this report.
EFFECT OF OPERATING ENVIRONMENT
ON PAH ANALYZER RESPONSE
          The purpose of the tests conducted in this task of the study was to evaluate the
performance of the Gossen, PAS lOOOi under operating conditions of high and low

temperature and relative humidity.  The motivation for these tests was the need to establish

the potential effects of operating conditions on the response of the PAH analyzer to

particulate-phase PAH. Investigation of such effects is particularly important in regard to the
possible application of the PAH analyzer in indoor/outdoor environments, where a wide
range of temperature and humidity conditions may be encountered.


      As discussed in Section 4.4, the tests were conducted in three steps:
      Step 1 Baseline Tests
      The base-line response of the PAH analyzer and  CNC to de-humidified cigarette
      smoke aerosol was determined by equilibrating the aerosol at a temperature of 20"C.
      The PAH analyzer was also equilibrated by operation inside the chamber at 20"C and
      50% R.H. for —2 hours prior to the tests.

      Step 2 Low-Temperature Tests
      The low temperature tests consisted of two parts:  In the first,  the PAH analyzer and
      the CNC were operated outside the test chamber  at room temperature (~25*C, 60%
      R.H.) and sampled smoke aerosol equilibrated at a temperature of 3*C. In the second
      part, the PAH analyzer was placed inside  the chamber at 3*C and 80%  R.H. and
      operated for a period of about 2 hours before sampling the low temperature-
      equilibrated cigarette smoke aerosol.
                                       42

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       Step 3 High-Temperature Tests
       The high temperature tests were conducted using the two-part procedure described
       above for the low temperature tests. The cigarette smoke aerosol was equilibrated at
       a temperature of 45 *C.  When operated inside the chamber, the PAH analyzer was
       equilibrated at 45*C  and 30% R.H. for about 2  hours prior to sampling the high
       temperature-equilibrated aerosol.
       The results from the  data collected at each test configuration were evaluated in two
 different respects ~ (a) impact of temperature and humidity operating conditions on PAH
 analyzer response and  (b) impact of sampled air temperature on PAH analyzer response.

       The impact of elevated and depressed temperature and humidity operating conditions
 (3*C/80% R.H., and 45'C/30% R.H.) on PAH analyzer response was studied as follows.
 For each test temperature (high or low), the response of the PAH analyzer as a function of
 the particle concentration of the temperature-equilibrated smoke aerosol was compared
 between the test configuration where the PAH analyzer  was operated inside the chamber and
 the configuration where the PAH analyzer was operated outside the chamber (at room
 temperature).

       The impact of the sampled air temperature on PAH analyzer response was evaluated
 by comparing the response of the PAH analyzer (as a function of number concentration) to
 the various  temperature-equilibrated  smoke aerosols when operated inside the chamber at the
 three different test conditions, 25'C  (baseline), 3'C (low-temperature), and  45*C (high
 temperature).

       Figure 5.7 shows the results of the baseline configuration tests conducted with the
PAH analyzer inside the environmental test chamber at 20"C and 50% R.H., sampling de-
humidified and temperature-equilibrated cigarette smoke aerosol.  The results show the
response of the PAH analyzer in pice-Amperes [pA] as a function of the particle
concentration measured by the CNC  [particles/cm3] for three separate runs.  The response is
observed  to be log-linear and reasonably correlated within each run, as well as between the
various independent runs.  The increasing scatter at higher particle concentrations may be

                                        43

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                     PAS RESPONSE AT ROOM TEMPERATURE CONDITIONS
                                            (2Q'C)

                                                          Environmental Test Chamber
                                                          Conditions: 20°C, 50% R.H.
                                                        -J-—   ..'.....'.....'..   '	'  '	L.
       10000
Particle Concentration
   CNC Reponse
   (particles/cmA3)
                                                                                100000
    Figure 5.7.  Response of the PAH analyzer to a temperature-equilibrated cigarette smoke
                          aerosol under baseline test conditions.
                                         44

-------
 due to differences in aerosol composition (and PAH content) that result from variations in
 combustion conditions within and between each cigarette.
       Figure 5.8 shows the results of the high temperature tests conducted at chamber
 conditions of 45 *C and 30% R.H.  The data shown in the figure are differentiated between
 those obtained in  a configuration where the PAH analyzer was inside the chamber and those
 where the PAH analyzer was outside the chamber (at room temperature) but sampled the
 same high temperature-equilibrated aerosol.  As Figure 5.8 shows, the data are essentially
 indistinguishable suggesting that the operating conditions do not have an observable impact
 on the response of the PAH analyzer.

       Figure 5.9 shows the results of the low temperature tests conducted at chamber
 conditions of 3*C and 80% R.H.  The data shown in the figure are again differentiated
 between those obtained in a configuration where the PAH analyzer was inside the chamber
 and those where the PAH analyzer was outside the chamber (at room temperature) but
 sampled the same low temperature-equilibrated aerosol. Figure 5.9 shows that the data from
 the two configurations are generally similar, although seemingly less uniform compared with
 the data from the  high temperature tests shown in Figure 5.8. The conclusion that the
 operating conditions do not have an observable impact on the response of the PAH analyzer
 appears to be largely applicable in this case also.

       The results in Figures 5.8 and 5.9 thus suggest that the temperature and humidity
 conditions under which the PAH analyzer is operated do not  significantly impact the response
of the PAH analyzer to temperature-equilibrated smoke aerosols at elevated and depressed
 temperatures.

       The data in Figures 5.7 — 5.9 can be further  used in conducting an analysis of the
impact of sampled air temperature on the response of the PAH analyzer a function of the
 smoke aerosol concentration. This analysis is presented in Figure 5.10, which shows the
PAH analyzer response as a function of particle concentration at each of the three test
temperatures, 20'C, 45 *C, and 3*C.  The best-fit response lines from logarithmic regression
                                         45

-------
      10
 

  S
CO
      0.1-•
     0.01
                     PAS RESPONSE AT HIGH TEMPERATURE CONDITIONS
                                            (45'C]
                          _1	1   I
       1000
                                                          LEGEND
                                                          • PAS inskte high temperature chamber
                                                          O High temperature equilibrated aerosol
                                                            (PAS at room temperature)
                                                          Environmental Test Chamber
                                                          Conditions; 45 "C, 3Q% R
       10000
Particle Concentration
   CNC Reponse
   (particles/cmA3)
100000
        Figure 5.8. Response of the PAH analyzer to a high temperature-equilibrated
                                 cigarette smoke aerosol.
                                           46

-------
o
(A
O
CO
O_
     0.01
        1000
                      PAS RESPONSE AT LOW TEMPERATURE CONDITIONS
                                             (3 «C)
                             0 o
                                      o*
 o  9
O
                                                           LEGEND
                                                           • PAS inside low temperature chamber
                                                           O Low temperature equilibrated aerosol
                                                             (PAS at room temperature)
                                                           Environmental Test Chamber
                                                           Conditions: 3 °C, 80% R.H.
        10000
 Particle Concentration
    CNC Reponse
    (parti cles/cmA3)
100000
         Figure 5.9  Response of the PAH analyzer to a low temperature-equilibrated
                                 cigarette smoke aerosol.
                                           47

-------
      10
      1"
o
CO
tn
CO
     0.1-
    0.01
                    PAS RESPONSE TO CIGARETTE SMOKE AEROSOLS
                       EQUILIBRATED AT VARIOUS TEMPERATURES

      1000
       10000
Particle Concentration
   CMC Reponse
   (particles/cmA3)
                           LEGEND
                           • 20 *C
                           O 45 »C
                           +  3'C
                                                                          100000
   Figure 5.10  Comparison of the response of the PAH analyzer as a function of particle
    number concentration to cigarette smoke aerosol at various sampled air temperatures.
                                     48

-------
 analysis are shown in Figure 5.10 for each of the three data sets, together with the individual
 regression coefficients for each temperature.  Figure S.10 appears to indicate a noticeably
 increasing PAH analyzer response as a function of sampled air temperature;  the increase in
 the response function is most pronounced at the elevated air temperature of 45'C, although a
 slight increase in the response function at 20*C compared with 3"C is also perceived.

       Possible explanations for the increase in the PAH analyzer response as a function of
 the sampled air temperature can only be surmised currently. The residence time (-2 seconds)
 of the smote aerosol within the elevated or depressed temperature environment is probably
 too short for a significant degree of intra-particle and particle-vapor phase redistribution of
 PAH.  More likely to be responsible for the effects observed may be the decrease in the
 ionization energy required at higher temperatures for photoemission of electrons from the
 PAH molecules. This decrease in the ionization energy barrier at higher air  temperatures
 may then have resulted in a greater efficiency of photoemission and consequently a larger
 electrometer response from the PAH analyzer.
AEROSOL TRANSMISSION EFHCIENCY
THROUGH THE PAH ANALYZER AND
MODIFICATIONS IN SAMPLING CONFIGURATION
       Aerosol transmission efficiency through the PAH analyzer was determined using
monodisperse NaCl test aerosols of five different sizes: 0.034 /tm, 0.06 ftm, 0.10 jtm,
0.20 /zm and 0.32 pm.  The CNC was used to determine the number concentration at the
sampling inlet of the PAH analyzer and downstream at various selected sampling locations
within the PAH analyzer.  Figure 5.11 is a summary of the overall results of the aerosol
transmission efficiency experiments.
      Figure 5.11 shows the particle penetration (or transmission) for both charged (+1)
and neutralized test aerosols from the sampling inlet to the electrometer inlet (see Figure 4.4
for a schematic of the PAH analyzer). The results demonstrate that the Electrofilter in the
                                        49

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modified configuration using metal tubing can provide a substantial improvement over the
transmission efficiency of the current sampling configuration in the analyzer.

       In order to verify that the modification does not result in deleterious effects on
analyzer performance, a series of tests were conducted. The main issue addressed was the
question of whether the modified configuration is subject to errors from the presence of non-
electrically neutral aerosols in typical indoor environments.  As a corollary, the expected
increase in PAH analyzer response due to the increased transmission of sampled aerosols was
also to be addressed.
      The experiments to address these issues were conducted in Battelle's Cafeteria.  The
cafeteria is a smoking environment (until 9/30/93) and the experiments were conducted as
follows:
      •   Three PAH analyzers were collocated with a CNC in the first series of tests, and
          operated as follows: Unit #1 analyzer was a modified configuration with the UV
          lamp ON;  Unit #2 analyzer was a modified configuration with the UV lamp
          OFF; Unit #3 analyzer was an original configuration with the UV lamp OFF.
      •   In the second series of tests, the three PAH analyzers and the CNC were again
          collocated in the cafeteria with the following operating  parameters: Unit #1
          analyzer was a modified configuration with the UV lamp ON;  Unit #2 analyzer
          was a modified configuration with the UV lamp OFF; Unit #3 analyzer was an
          original configuration with the UV lamp ON.

      The results of the first series of tests are shown in Figure 5.12, which shows the
response profile as a function of time for each of the three PAH analyzers and the number
concentration measured by the CNC.  The response of Unit #1 tracked closely with the
particle concentration measured by the CNC, and was consistent with the presence of
smokers in the cafeteria at different times during the sampling period.  The response profiles
of Units #2 and #3 were very similar and were almost always between 0.000 ±0.003 pA,
with maximum observed responses of +0.009 and -0.003 pA.  This result indicates that non-
                                        51

-------
Particle Concentration
    (number/cm3)
                              (Vd)
                   asuodsay J8}9uiojp3|g sVd
I
U.
                                  52


-------
 -electrically neutral aerosols do not have a significant presence in typical indoor air, and
 neither is there a significant presence of gaseous ion non-neutrality.  Compared with the
 response of the operating (modified) PAH analyzer (Unit #1), the background electrometer
 response of the modified analyzer Unit #2 (UV OFF) was negligible. These results suggest
 that the modified configuration would not be subject to significant errors from the presence of
 non-electrically neutral aerosols in typical indoor environments.  Further, the Etectrofilter in
 the original configuration PAH analyzer is only partially efficient for particle sizes
 >0.06 /*m and cannot guarantee a zero electrometer baseline either.

       The results from the second series of tests are shown in Figures 5-13 and 5-14.  The
 top graph in both figures shows the response profiles as a function of time for  the two
 operating (UV ON) analyzers - Unit # 1 with the modified configuration and Unit #3 with
 the original sampling configuration.  The middle graph  is a trace of the response of Unit #2
 with the modified configuration and the UV lamp OFF  - an indication of the baseline
 electrometer response of the modified configuration analyzers.  The bottom graph is a trace
 of the particle concentration measured by the CNC during the course of the two tests.

       Figure 5.13 reports the data collected during 2 hours of sampling through the lunch
 hour from 11:10 a.m. to 1:10 p.m. in the cafeteria. Figure 5.14 reports data collected
 during a subsequent sampling period of 15 minutes during which a cigarette was smoked in
 close proximity to the location of the three PAH analyzers and the CNC.

       The results shown in Figure 5.13 reveal that under conditions of high particle loading
 (30,000 - 100,000 particles/cm3) and presence  of ETS from continual smoking activities in
 the microenvironment, the modified PAH analyzer had a consistently higher response than
 the original configuration PAH analyzer. This result is  consistent with the higher
 transmission efficiency of the modified configuration. Throughout the sampling period
 shown in Figure 5.14 the response from Unit #2, a modified analyzer with UV  OFF, was
less than ±0.005, a negligible fraction of the response of the operating modified analyzer,
Unit #1.
                                          53

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       The results in Figure 5.14 for the short duration test conducted with cigarette smoking
 in close proximity to the analyzers were similar to the responses observed during the longer
 sampling period.  In this case, however, a larger baseline electrometer response was
 observed from Unit #2 (modified, UV OFF) during several brief periods in the test.  This
 result is consistent with the presence of freshly generated combustion aerosols.  However,
 the magnitude of charge on the nbn-electrically neutral aerosol is extremely small compared
 with the photoionization response and was under 2-5%  at all times.  Also, the baseline
 electrometer response is extremely transitory and is consistent with the rapid neutralization in
 the air of the charged aerosols.  Thus, even under worst-case conditions and high particle
 loadings, the modified configuration analyzer does not appear to suffer any negative
 consequences as a result of by-passing the Electrofilter.

       The results of the experiments shown in Figures 5.13  and 5.14 were also used to
 determine the percentage increase in analyzer response resulting from the modification. This
 increase in analyzer response is shown graphically in Figure 5.15.  The top graph in the
 figure refers to the two-hour sampling period in Figure 5.13,  while  the bottom graph refers
 to the 15 minute sampling period in Figure 5.14. The result  from  the top graph
 demonstrates that under typical indoor conditions, there is about a 25-30% increase in
analyzer response.  The graph at the bottom of Figure 5.15 indicates that during the period
of close proximity cigarette smoking, the modified analyzer continued to yield a higher
response on average than the original analyzer.  Short periods during which the original
analyzer had a higher response are probably due to non-homogeneous smoke concentrations
in the sampling environment.  A systematic comparison of the response of the modified and
original analyzers using the cigarette smoke generator could not conducted within the time
constraints of this study.
                                          55

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PAH ANALYZER RESPONSE TO NON-PAH
LABORATORY TEST AEROSOLS
       Tests with non-PAH NaCl test aerosols in the previous evaluation study5 had found
that the PAH analyzer had a small, but not insignificant, response to these test aerosols.  In
our earlier study, the non-PAH response tests were conducted using polydisperse NaCl
aerosols of three different count median diameters (CMD), 0.04 pm, 0.08  /tm and 0.15 /xm
and a log-normal standard deviation of crg—2.0. The aerosols were generated by nebulizing
solutions of appropriate concentrations of sodium chloride in water and drying  the nebulized
droplets to form the solid NaCl test aerosol.

       The response of the PAH analyzer to these non-PAH aerosols varied linearly with
particle number concentration for each polydisperse aerosol5.  In addition,  the response was
proportional to the size of the test aerosol, i.e., the 0.15 pan CMD polydisperse aerosol
resulted in a higher response, normalized to particle number concentration, than the 0.08 /*m
CMD aerosol which in turn resulted in a higher response than the 0.04 tim CMD aerosol.
The normalized response to the 0.04, 0.08 and 0.15 pm CMD aerosols was approximately
0.009, 0.015 and 0.036 pA, respectively, for 10,000 particles of each test  aerosol entering
the PAH analyzer. Note that these response rates are normalized to the number
concentration entering the PAH analyzer; since different sizes of particles entering the
analyzer have different transmission efficiencies (see Figure 5.11),  the relationship between
analyzer response and particle size is somewhat convoluted. In addition, since the test
aerosols were not monodisperse (of a single particle size), it was difficult to interpret the
precise relationship of the response with particle size.
       Considering these difficulties with interpreting the results of the previous study, we
attempted to obtain the response of the PAH analyzer for various monodisperse particle sizes
spanning the size range typical of indoor aerosols, 0.01 - 0.5 /tm.  We selected the same five
monodisperse particle sizes used in the aerosol transmission efficiency tests (see Table 4.2),
                                         58

-------
 namely, 0.034, 0.06, 0.10, 0.20, 0.32 pm.  Also in order to by-pass the issue of particle
 size dependent transmission efficiency through the PAH analyzer, particle concentration
 measurements were made at the inlet of the electrometer (see Figure 4.8).  The response of
 the PAH analyzer to each monodisperse test aerosol was normalized to the number
 concentration measured at this location.

       A number of different aerosols were used to test the PAH analyzer, as discussed in
 Section 4.6.  Prior to testing the response of the PAH analyzer, each monodisperse aerosol
 was first sampled by the analyzer with the UV lamp OFF. The electrometer response in this
 operating condition was checked to be within 0.000 ±0.005 pA, to ensure that the test
 aerosol was electrically net-neutral.  The subsequent analyzer response with the UV lamp
 operational could then be ascribed completely to photoionization effects.  This check-out
 procedure was found to be essential since aerosols emerging immediately from a Kr-85
 neutralizer may not be electrically neutral. We found that the use of the mixing chamber
 was very helpful in allowing the aerosols to become net electrically neutral, probably because
 it allowed a longer time period from the time the aerosol exited the neutralizer to when it
 entered the analyzer.

       For all the test aerosols the response of the PAH analyzer varied linearly with particle
 number concentration  at each monodisperse particle size.  This result is consistent with mat
obtained in our previous study, and is  further evidence that the response is due to
photoionization effects.  The response of the  PAH analyzer to the various test aerosols can
also be compared as a function of particle size, aerosol material and nebulizing solvent.
Figure 5.16 is a comprehensive summary of the results of the response tests. The figure
shows, for each type of aerosol generated,  the PAH analyzer response normalized to the
number of particles entering the electrometer. The figure also shows the surface area (in
/im2) as a function of particle size over the size range of the tests.

       As shown in Figure 5.16, the most obvious result from the tests is that for sodium
chloride and ammonium sulfate aerosols, both generated from water solutions, the
                                          59

-------
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                              60

-------
 normalized responses as function of particle size are almost identical (within experimental
 error) to each other.  In addition, the normalized response correlates very well with the
 particle surface area.  This result is further evidence that the response is a surface
 phenomenon and is due to photoionization of substance or substances unknown deposited on
 the surface of the aerosols.  The fact that identical responses are observed for both sodium
 chloride and ammonium sulfate aerosols confirms our earlier suspicions5 that the response is
 related to contaminants.  The normalized response is also consistent with the results obtained
 from the previous study for polydisperse aerosols, after corrections for size-dependent
 transmission efficiency are considered.

       To further investigate the origin of the response, phthalic anhydride test aerosols were
 generated from a water solution.  The normalized response to this aerosol, shown in
 Figure 5.16, is similar in magnitude to the sodium chloride/ammonium sulfate response,
 although a little more scatter in the data is observed. The lack of a higher response indicates
 that the response  from sodium chloride and ammonium sulfate is not due to  phthalic
 anhydride contamination.  Phthalic anhydride is a common contaminant found in paniculate
 air samples analyzed for PAH using conventional GC/MS methods.  The selection of phthalic
 anhydride for these tests was motivated by the supposition  that it was the contaminant
 causing the photoionization response observed in laboratory non-PAH aerosols.

       In  a final series of tests, phthalic anhydride and di-octyl phthalate (DOP) aerosols
 were generated from iso-propyl alcohol (IPA) solutions.  The results from these experiments,
 shown in Figure 5.16, revealed that the normalized response to these test aerosols was less
 than the corresponding responses from aerosols  generated from water solutions.  In
particular,  the comparison of responses from phthalic anhydride aerosols generated from IPA
 and water solutions showed that the IPA-generated aerosols had  a substantially lower (note
 the logarithmic response scale  in Figure 5.16) response than the water-generated aerosol.
 The response from the DOP aerosol was even lower and more scattered.  One key difference
 between DOP and the other test aerosols is that  DOP is a liquid aerosol at room temperature
 conditions, while the others are solid aerosols.
                                          61

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       The difference in analyzer response depending on whether the aerosols were generated
 from water or from IP A solutions suggests that photoionization is occurring due to the
 presence of contamination in the solvent.  As the nebulized droplets are dried, the
 contamination in the solvent may be deposited on the surface of the particle.  In fact, the
 drying process may be concentrating the contaminants on the particle surface as the solvent
 evaporates from the surface.

       Distilled, deionized (10I8M-ohm) water and analytical grade IPA were used to prepare
 all solutions used in the experiments — it is therefore difficult to theorize on the origin of the
 contamination. Most likely, however, the contamination is organic in nature and is
 ubiquitous.  The PAH analyzer was also tested by nebulizing and drying blank solutions of
 both IPA and water — no response was observed in either case.  This result is  consistent
 with a surface-based photoionization mechanism. Without the presence of a non-volatile
 substance in the solution,  there is no surface for the contaminant(s) to be deposited.  If the
 contaminant is non-volatile, the blank solution would have resulted in ultrafine particles,
 probably < 0.015 pan in diameter with insufficient surface area for a response from the
 analyzer.  If the organic contaminant is semi-volatile, the lack of particle surfaces from the
 blank solution may have resulted in the contaminant being present completely in the vapor
 phase.

       A final noteworthy observation in this regard is the typical response of the PAH
 analyzer under "clean" (non-ETS) conditions in indoor air.   Under these conditions, and at a
 particle concentration  of 10,000 - 15,000 particles/cm3, the analyzer response is usually less
 than 0.02 - 0.03 pA.  The typical indoor aerosol  under clean (no paniculate source)
 conditions has a particle size CMD of 0.15-0.3 /tm.  Based on the sodium
 chloride/ammonium sulfate responses in Figure 5.16, the background photoionization
response  under typical clean indoor air conditions should be > 0.1 pA. Clearly, such a large
response  is not observed.  This inconsistency suggests that the laboratory generated non-PAH
aerosol are somehow artificially enriched in the non-PAH contaminant(s) that are causing the
observed photoionization response.   To determine how much of the typical response in
                                          62

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 indoor air is due to non-PAH contaminants will therefore require the knowledge of the nature
 of the contaminant. Also, a more sophisticated aerosol generation technique would be
 required that better emulates the indoor aerosol while ensuring the absence of PAH.
 FIELD STUDY AND
 INTERCOMPARISONS
       The objectives of the pilot field study were to (1) conduct a field evaluation of the
 performance of the PAH analyzer and (2) compare the measured particle-bound (<2.5 /tin)
 PAH concentrations from the integrated indoor sampler and GC/MS analysis with the
 average responses of the PAH analyzer during the corresponding 24-h sampling periods.
 The PAH analyzer was found to operate in a very satisfactory manner throughout the study.
 The unit was portable, and easy to set up in the house for operation by one person.  None of
 the residents voiced any complaints regarding the unit's operation.

       The measured concentrations for individual PAH and alkylated PAH compounds from
 the eight sample homes are summarized from  Tables 5.3 through 5.10. The measured PAH
 concentrations in the field blank sample is given in Table 5.11.  The field blank consisted of
 a clean filter and XAD-2 trap which were taken to House H03RN and placed on the
 sampling train without sampling. The filter and XAD-2 trap were then transported back to
 Battelle for analysis. The field blank contained trace amounts of 2- to 4-ring PAH.  The
 measured PAH concentrations reported in Tables 5.3 through 5.10 were corrected for the
 PAH concentrations in the field blank. Note that the reported concentrations only represent
 the fine particulate-bound (<2.5 /im) PAH concentrations.  As described in Section 4.7, the
 impactor-denuder sampling train removes coarse particles >2.5 jtm in aerodynamic diameter
 in the impactor, with vapor-phase PAH being  subsequently removed by the denuder.

      The fine particulate-bound PAH concentrations in indoor air were higher in the
 smokers'  houses than that in the non-smokers' houses.  Among the eight houses, the highest
PAH concentrations in  indoor air were found in house H06RS.  In this house, a total of
                                       63

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  TABLE 5.3 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H01RS.
                    Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Melhylphenanthrene isomers
       C2-alkyIphenanthrene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA<'>
          NA<*>
            13
          NA<*>
            23
             1.3
            14
             2.0
             3.3
             1.8
             0.33
             0.087
             0.15
             0.27
           <0.03
             0.18
             0.43
             0.42
             0.46
             0.21
             0.23
             0.28
             0.070
             0.063
           62
(a)  Not applicable, due to interference compounds from the denuder tube.
                                    64

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  TABLE 5.4  MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                           THE AIR IN HOME H02RN
                    Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthrene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indenofl ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a, hjanthracene
       Coronene
       Sum of PAH
          NA<*>
          NA<*>
             9.6
          NA<*>
          NA<*>
          NA<*>
            18
             1.2
             6.8
             2.0
             1.9
             1.7
             0.22
             0.060
             2.12
             0.17
           <0.03
           <0.03
             0.21
             0.24
             0.15
           <0.03
             0.16
             0.12
             0.056
             0.045
            43
. (a) Not applicable, due to interference compounds from the denuder tube.
                                      65

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  TABLE 5.5 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                         THE AIR IN HOME H03RN
                   Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthrene isomers
       Fluoianthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA«
          NA<*>
             8.4
          NA<*>
          NA«
          NA«
            16
             0.92
             7.8
             1.4
             0.79
             0.66
             0.15
             0.052
             0.053
             0.12
           <0.03
           <0.03
             0.27
             0.16
             0.21
           <0.03
             0.071
             0.090
           <0.03
           <0.03
            37
(a)  Not applicable, due to interference compounds from the denuder tube.
                                     66

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  TABLE 5.6 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H04RS
                    Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthrene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA<*>
          NA«
             8.8
          NA<«>
          NA<»>
          NA<*>
            30
             1.7
            16
             3.8
             3.9
             3.2
             0.40
             0.11
             0.26
             0.19
           <0.03
           <0.03
             0.23
             0.27
             0.32
           <0.03
             0.31
             0.19
             0.062
             0.11
           70
(a)  Not applicable, due to interference compounds from the denuder tube.
                                     67

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  TABLE 5.7 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H05RS
                    Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthrene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA<«>
            16
          NA<*>
          NA
            35
             1.5
            19
             8.7
             3.6
             2.9
             0.47
             0.22
             0.22
             0.37
           <0.03
             0.062
             0.29
             0.27
             0.36
             0.16
             0.45
             0.28
             0.086
             0.043
            90
(a)  Not applicable, due to interference compounds from the denuder tube.
                                     68

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  TABLE 5.8 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H06RS
                    Compound
Concentration, ng/m3
       Naphthalene
       Acenaphthene
       Acenaphthylene
       Biphenyl
       Methylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthiene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c »d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a, h]anthracene
       Coronene
       Sum of PAH
          NA<»>
          NA(a>
            30
          NA<*>
          NA(a)
            55
             2.3
            50
             4.5
             4.4
             3.7
             0.85
             0.57
             0.21
             0.39
           <0.03
             0.076
             0.35
             0.26
             0.36
             0.65
             0.48
             0.35
             0.094
             0.052
          150
(a)  Not applicable, due to interference compounds from the denuder tube.
                                     69

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  TABLE 5.9 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H07RN
                    Compound
Concentration, ng/m3
       Naphthalene
       Accnaphthene
       Acenaphthylene
       Biphenyl
       Mcthylbiphenyl isomers
       Fluorene
       Phenanthrene
       Anthracene
       Methylphenanthrene isomers
       C2-alkylphenanthrene isomers
       Fluoranthene
       Pyrene
       Methylpyrene isomers
       C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA<»>
          NA<*>
             6.0
          NA(a>
          NA<*>
          NA<*>
            16
             0.61
             1.6
             5.2
             1.6
             1.3
             0.16
           <0.03
           <0.03
             0.050
           <0.03
           <0.03
             0.065
             0.040
             0.041
           <0.03
             0.068
             0.046
           <0.03
           <0.03
           33
(a)  Not applicable, due to interference compounds from the denuder tube.
                                    70

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  TABLE 5.10 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                          THE AIR IN HOME H08RN
                    Compound
Concentration, ng/m3
        Naphthalene
        Acenaphthene
        Acenaphthylene
        Biphenyl
        Methylbiphenyl isomers
        Fluorene
        Phenanthrene
        Anthracene
        Methylphenanthrene isomers
        C2-alkylphenanthrene isomers
        Fluoranthene
        Pyrene
        Methylpyrene isomers
        C2-alkylpyrene isomers
       Benz[a]anthracene
       Chrysene
       Cyclopenta[c,d]pyrene
       Methylbenz[a]anthracene isomers
       Benzofluoranthenes
       Benzo[e]pyrene
       Benzo[a]pyrene
       Methylbenzofluoranthene isomers
       Indeno[l ,2,3-c,d]pyrene
       Benzo[g,h,i]perylene
       Dibenzo[a,h]anthracene
       Coronene
       Sum of PAH
          NA<«>
             7.0
          NA<»>
          NA(*>
          NA<*>
           32
             1.5
             7.8
             2.4
             1.7
             1.3
             0.18
           <0.03
             0.63
             0.10
           <0.03
           <0.03
            0.16
            0.24
            0.24
           <0.03
            0.075
            0.065
          <0.03
          <0.03
           55
(a)  Not applicable, due to interference compounds from the denuder tube.
                                     71

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 TABLE 5.11 MEASURED PAH AND ALKYLATED PAH CONCENTRATIONS IN
                        THE FJELDrBLANK SAMPLE
                   .Compound
Concentration, n
        Naphthalene
        Acenaphthene
        Acenaphthylene
        Biphenyl
        Methylbiphenyl jsomecs
        Huorene
        Phenanthrene
        Anthracene
        Methylphenanthrjene isomers
        C2-alkylphenanthrene isomers
        Fluoranthene
        Pyrene
        MethyjipyTene isomers
        C2-alkylpjoBne isomers
        Benz[a]anthracene
        Chrysene
        Cyclopenta[c,d]pyrene
        Methyjbenz[a]anthracene isomers
        Benzofluoranthenes
        Benzo[e]pyrene
        Benzo[a]pyxene
        Methylbenroflupranthene isomers
        Indeno[l ,2,3-e,d]pyrene
        Benzo[g,h,i]perylene
        Dibenzofa, h]anthracene
        Coronene
        Sum of PAH
              2.3
              0.59
              0.12
              0.79
            <0.03
              1^
              2.9
              0.15
              0.047
            •C0.03
              0.26
              0.18
            <0.03
            <0.03
            <0.03
              0.057
            <0.03
            <0.03
            <0,03
            <0.03
            <0.03
            <0.03
            <0.03
            <0.03
            <0.03
            <0.03
              8.9
(a)  Assume the total sample volume is 25 m3
                                     72

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 seven cigarettes were smoked during the 24-h sampling period.  The numbers of cigarettes
 smoked were three (3) in H01RS, two (2) in H04RS, and five (5) in H05RS.

        Note that    in Tables 5.3 - 5.11, the concentrations of a few volatile PAH such as
 naphthalene, biphenyl acenaphthene, and fluorene could not be accurately measured.
 Off-gassing of volatile chemical species from the silicone grease used to coat the impactor and
 the denuder apparently occurred during sampling, causing these species to be collected in the
 filter/XAD-2 trap. These species interfered with the quantification of the above-mentioned
 volatile PAH. Since most of these volatile PAH are present almost exclusively in the vapor
 phase10'11, they are not expected to contribute significantly to the  fine particle-bound PAH
 concentrations.

       The response of the PAH analyzer as a function of time during the corresponding
 24-h sampling period in each house is shown in Figure 5.16 through 5.23. As shown in
 these figures, the responses of the PAH analyzer in non-smokers' houses were less than
 0.1 p Amp.  Higher responses were observed in the smokers' houses.  Note that house
 H07RN is equipped with a high performance paniculate filter and would consequently have
 low particle concentrations in indoor air. In this house, the PAH analyzer did not have a
 response during most the 24-h sampling period, as shown in Figure 5.22.

       The PAH analyzer's response as a function of time in each sample home was
 averaged to provide an average response over each sampling period (in pAmp).  The average
 PAH analyzer response for each sample home was then converted to an average PAH
 concentration  (ng/m3) by using the conversion factor of 3,000 ng/m3/p Amp provided by
 Gossen, GmbH and Eco Chem Technologies, Inc. These average PAH concentrations were
then compared with the fine particle PAH concentrations measured from GC/MS analysis of
the corresponding integrated samples.
                                        73

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                          HO IRS PAH
                       ANALYZER DATA
PAH
SIGNAL
(pAmp)
                   300
  600      900
TIME (minutes)
1200      1500
  Figure 5.17 Response of the PAH analyzer during the 24-h sampling period in H01RS.
                            74

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         0.1
        0.08
        0.06-
PAH
SIGNAL
(pAmp)o.o4
        0.02-
          0
                          H02RN PAH
                        ANALYZER DATA
                   300      600       900      1200     1500
                        TIME (minutes)
   Figure 5.18 Response of the PAH analyzer during the 24-h sampling period in H02RN.
                          75

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                           H03KNP&H
                        AMALYZER DAfA
         0.06
         0.04--
PAH
SIGNAL
(pAmp)
         0.02- •
                   300      600      900      1200     1500
                        TIME (minutes)
    Figure 5.19 Response of the PAH analyzer during the 24-h sampling period in H03RN.
                            76

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          0.2
         0.16--
         0.12
PAH
SIGNAL
(pAmp) o.os
        0.04-
                           H04RS PAH
                        ANALYZER DATA
                   300
600
900
                                            1200      1500
                        TIME (minutes)
   Figure 5.20 Response of the PAH analyzer during the 24-h sampling period in H04RS.
                             77

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         0.8
         0.6--
PAH
SIGNAL
(pAmp)
0.4-
         0.2--
          0-
                          H05RS PAH
                       ANALYZER DATA
           0        300      600       900      1200      1500
                         TIME  (minutes)
    Figure 5.21 Response of the PAH analyzer during the 24-h sampling period in H05RS.
                            78

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                          H06RS PAH
                        ANALYZER DATA
         0.8
         0.6--
PAH
SIGNAL
(pAmp)
0.4-
         0.2--
          300
    600      900
TIME (minutes)
                                            1200      1500
    Figure 5.22 Response of the PAH analyzer during the 24-h sampling period in H06RS.
                            79

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        0.01
        0.01-•
PAH
SIGNAL'
(pAmp)
        0.01
          0-
          0-
           o
                          H07RNPAH
                       ANALYZER DATA
                                     n
300       600      900      1200      1500
     TIME (minutes)
   Figure 5.23 Response of the PAH analyzer during the 24-h sampling period in H07RN.
                           80

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         0.1
        0.08-
PAH
SIGNAL
(pAmp)
0.06
        0.04--
        0.02--
          0
           0
                          H08RN PAH
                       ANALYZER DATA
           300
600
900
                        TIME (minutes)
1200      1500
    Figure 5.24 Response of the PAH analyzer during the 24-h sampling period in H08RN.
                           81

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       Table 5.12 summarizes the sum of the measured fine particle-bound concentrations of

 individual PAH and alkylated PAH compounds (referred to as fine particle PAH) and the

 average PAH analyzer-based concentration. The measured fine particle PAH concentrations

 were about one-half to two-times of the average PAH concentrations from the PAH analyzer

 in non-smokers' houses. In the smokers' houses, the measured PAH concentrations ranged
 from 0.28 to 1.3 times of the average PAH concentrations of the PAH analyzer.
         TABLE 5.12  COMPARISON OF FINE PARTICULATE-BOUND PAH
                     CONCENTRATIONS MEASURED FROM THE
                     INTEGRATED SAMPLERS AND CORRESPONDING
                     AVERAGE RESPONSES FROM THE PAH ANALYZER
 House Codew
 Fine Particle PAH
    Measured00
Concentration, ng/m3
Average PAH Analyzer-Based(c)
     Concentration, ng/m3
H01RS
H02RN
H03RN
H04RS
H05RS
H06RS
H07RN
H08RN
62
42
37
70
90
150
33
55
220
76
45
53
240
300
ND
35
(a)  In H01RS, H01R refers to the house code, and S refers to a smoker's house.  In
    H02RN, H02 refers to the hose code and N refers to a non-smoker's house.

(b)  Measured concentration is the sum of individual PAH concentrations determined from
    GC/MS analysis of the combined filter and XAD-2 trap from the integrated sampler
    equipped with an impactor and denuder upstream of the filter and XAD-2 trap.

(c)  A conversion of 3,000 ng/m3/p Amp was used to calculate the average PAH
    concentration from the PAH analyzer's average response during each 24-h sampling
    period.

(d)  ND denotes not detected.
                                     82

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                                            iCES
 (1)      Burtscher, H. Schemer, L., Siegmann, H.C., Schmitt-Ott, A. and Federer, B.
         Probing aerosols by photoelectric chargin.  J. Appl. Phys. 53(5), 3787, 1982.

 (2)      Burtscher, H., Niessner, R. and Schmitt-Ott, A. In-situ detection by photoelectron
         emission of PAH enriched on particle surfaces, in Aerosols: Science, Technology,
         and Industrial Applications of Airborne Particles.  Edited  by Liu, B. et al.,
         Elsevier, New York, 1984, p. 443.

 (3)      Niessner, R.  The chemical response of the photo-electric aerosol sensor (PAS) to
         different aerosol systems.  J. Aerosol Sci., 17(4), 705, 1986.

 (4)      McDow, S.R., Giger, W., Burtscher, H., Schmitt-Ott, A., Siegmann, H.C.
         Polycyclic aromatic hydrocarbons and combustion aerosol photoemission, Atmos.
         Env. 24A(12), 2911, 1990.

 (5)      Chuang, J.C. and Ramamurthi, M. Evaluation of a Gosson, GmbH Model PAS
         lOOOi photoelectric aerosol sensor for real-time PAH analyzering, Final Report,
         EPA Contract Number 68-DO-0007, Work Assignment 13, 1992.

 (6)      Lane, D.A., Sakuma, T., Ouan, E.S.K.  Real-time analysis of gas phase polycyclic
         aromatic hydrocarbons using mobile atmospheric pressure chemical ionization mass
         spectrometer system, Reprinted from Polynuclear Aromatic Hydrocarbons: Fourth
         International Symposium on Analysis, Chemistry, and Biology, Battelle Press,
         Columbus, Ohio, 1980.

(7)       Liu, B. Y.H. and Lee, K.  An aerosol generator of high stability, Amer. Ind. Hyg.
         Assoc., December 1965, p.861.

(8)       Liu, B.Y.H. and Pui, D.Y.H.  A sub-micron aerosol standard and the primary,
         absolute calibration of the Condensation Nucleus Counter, J. Colloid Int. Sci.,
         47:155,  1974.

 (9)      Chuang, J.C., Callahan, P.J., Katona, V., and Gordon, S.M.  Develop and
         evaluate monitoring methods for polycyclic aromatic hydrocarbons in house dust
         and track-in soil, Final Report, EPA Contract Number 68-DO-0007, Work
         Assignment 35, 1993.

 (10)   *  Wilson,  N.K., Chuang, J.C., Kuhlman, M.R., Mack, G.A., and Howes, Jr., J.E.
         A quiet sampler for the collection of semivolatile organic pollutants in indoor air,
         Environ. Sci. and Technol., 23(9),  1112, 1989.
                                         83

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 (11)    U.S. EPA.  Compendium Chapter JP-9, Determination of Reactive Acidic and
         Basic Gases and Participate Matter in Indoor Air, Atmospheric Research and
         Exposure Assessment Laboratory, U.S. Environmental Protection Agency,
         Research Triangle Park, North Carolina, 1989.

(12)     Coutant, R.W., Callahan, P.J., and Chuang, J.C. Development of an efficient
         compound annular denuder for determining indoor phase distributions of
         semivolatile organic compounds, EPA Contract No. 68-02-4127, 1989 Final
         Report.

(13)     Coutant, R.W., Callahan, P.J., Kuhlman, M.R., and Lewis, R.G. Design and
         performance of a high-volume compound annular denuder, Atmos. Environ., 23,
         2205, 1989.

(14)     Chuang, J.C., Gregory, A.M., Kuhlman, M.R., and Wilson, N.K. Polycyclic
         aromatic hydrocarbons and their derivatives in indoor and outdoor air in an eight-
         home study, Atmos. Environ. 25B(3), 319, 1991.
                                       84

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                                    APPENDIX A

                   SMOKE GENERATOR STANDARD PROTOCOL
         The following step-wise procedure should be followed when using the cigarette
 smote generator for field (or laboratory) evaluation of a Gossen PAS Model lOOQi.  The
 procedure assumes that the smoke generator is in working order and all regular maintenance
 requirements as outlined subsequently have been fulfilled.

 EXPERIMENTAL
 1.
2.
    Turn the power switch on the smoke generator to ON; the noise of the pump should be
    heard immediately and several of the rotameter should register some amount of air flow.

    Pull the cigarette combustion chamber tube away from the front panel so that the
    cigarette holder is disconnected from the tube. A silicone gasket on the outer rim of the
    cigarette holder provides the seal with the tube; vacuum grease on the gasket will help to
    make disassembly and re-assembly of the tube easier.

3.  Insert a University of Kentucky research cigarette into the cigarette holder. The
    cigarette will most likely be only loosely held by the holder. A small piece of thin
    tissue or laboratory wipe wrapped around the end of the cigarette inserted into  the holder
    will help to make a snug fit.  Insert about a % of an inch of the cigarette into the holder.

4.  Re-assemble the cigarette combustion chamber.

5.  After waiting about 30 seconds for the system to re-equilibrate, check and set the
    various flows to the nominal levels stated in Figure  1.  If the Calibration Smoke Feed
    flow is not sufficient, the adjustable needle valve inside the box enclosure may  need to
    be closed further.  Looking at the box from the front-right hand side, the needle valve is
    closed further by clock-wise rotation of the screw using an appropriately sized screw-
    driver.  Do not tighten the screw by more than V4-V4 rotation each time.  Close the
    valve to the extent necessary to be able to maintain a steady flow of 25 cc/min  through
    the Calibration Smoke Feed rotameter.
6.
    Connect a W" diameter tube to the Smoke Outlet on the front panel of the smoke
    generator. Connect the other end of the tube to a tee connector. The PAS can be
    connected to one of the other two openings of the tee connector. The third opening
    should be connected to a tube that appropriately vents the excess air flow.  Note that the
    excess air will contain a low but odorous concentration of cigarette smoke. A
    datalogger is extremely useful to record the response of the PAS to the cigarette smoke
    generated in the test. The datalogger should be set to record data at 10 second intervals
    over a test duration of 15 minutes. Do not start data acquisition at this point, however.
                                        85

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 6.   After setting the flows as specified, disassemble the Cigarette Combustion Chamber
     again by pulling the tube outward. Using a butane lighter, light about a % of an inch of
     the cigarette at the opposite end from the cigarette holder.  Ensure that the end is
     completely on fire, including the tobacco in the middle. The process of lighting the
     cigarette may take up to 10 seconds. It is extremely important to light the cigarette
     well, otherwise it WILL get extinguished. A butane lighter is also highly recommended,
     as it is very difficult to accomplish a good starting burn using a match.

 7.   After lighting the cigarette, reassemble the Cigarette Combustion Chamber.

 8.   Pay dose attention to the Calibration Smoke Feed fotameter readout. It should rise
     from  near zero back up to the initial setting  of 25 cc/min within about 20 seconds. If
     necessary adjust the rotameter valve to obtain the required flow rate.

 9.   Start acquiring PAS response data with the datalogger when all this flows are at or within
     10%  of their required values.

 10.  Continue to monitor the flows for the next 12-15 minutes, making minor adjustments as
     necessary. The Cigarette Smoke Combustion Air and Calibration  Smoke Feed flows
     will tend to fluctuate.  Some amount of variability in these two flows is unavoidable. It
     is satisfactory if the Combustion Air flow remains in the range of 60-75 cc/min and the
     Smoke Feed is within 20-30 cc/min.

 11.  Keep  a close watch on the PAS response, particularly within the first 2-3 minutes of the
     test.  If the response falls to zero and does not change for more than 30-45 seconds, the
     cigarette has become extinguished.  It is then necessary to abort the test. Cease data
     acquisition, and remove the unburnt cigarette inside the combustion chamber.  Replace
     with a new cigarette and re-start the process. The likely causes of a cigarette becoming
     extinguished are: (a) cigarette not adequately lit at the start; (b) cigarette not held snugly
    by the holder; (c) cigarette was bumped when the Combustion Chamber was
     reassembled;  (d) Combustion Air was insufficient.

    If the PAS response is continuously below 0.05 pA during a test and opening the
    Combustion Chamber during the run reveals that the cigarette is burning, then improper
    function of the PAS may be indicated.   To confirm that the PAS is not functioning
    properly, check that the smoke generator's flows are at their nominal values and that
    flow paths to the PAS are correctly connected.

12.  After  a data acquisition period of 12-15 minutes, terminate data acquisition.
    Disassemble the Combustion Chamber and remove the burning cigarette. Extinguish the
    cigarette and dispose appropriately.

13.  If no further tests are to be conducted, allow about 10 minutes for the Mixing Chamber
    to flush completely before powering off the smoke generator.
                                          86

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DATA ANALYSIS

1.  Transfer the data from the datalogger to a computer data file and import the file into a
    spreadsheet. The data should consist of a series of rows of PAS response in pA.  There
    will be approximately 72-90 responses for each run, assuming that data were collected
    every 10 seconds over a period of 12-15 minutes.

2.  Calculate the geometric mean response and the geometric standard deviation of the data
    collected in each run.  Compare these calculated values with those obtained in  laboratory
    tests with the PAS, as shown in Table 1.

    The geometric mean response, rg, is calculated as:
                                 rg = exp [-
                                          S tar,
                                                 ] ,
    where rt is the PAS response for the r* data point of a total of n data points.

    The geometric standard deviation, ag, is calculated as:
3.
    where rg is as calculated above.

    If possible, plot a frequency distribution of the PAS responses in each run.  Use the
    same number of bins (10) and logarithmic range of 0.01-2.0 pA as in Figure 6.
    Compare these results with  those in Figure 6 obtained from laboratory tests with the
    PAS.

    If only a qualitative analysis is desired, then review the general range of the PAS
    responses, and compare them with the range of responses observed in the laboratory
    tests, as shown in Figure 4. The PAS response typically varies between 0.1 and 1.0 pA,
    with an average value of about 0.25-0.35 pA.  The presence of peaks and valleys in the
    response curve as a function of time is also indicative of typical performance of the
    PAS.

    If the PAS response is continuously below 0.05 pA during a test and the smoke
    generator was operating properly according to all flow and cigarette burn sight
    indicators, then it may be concluded that the PAS is not functioning correctly. The PAS
    may then need to be removed from  the field site and further laboratory tests conducted
    to determine the origin of the problem.

                                         87

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 SMOKE GENERATOR MAINTENANCE

     The smoke generator requites regular maintenance for a few components. These
 components are listed below and estimated intervals for replacement or service are provided.

 1.   Needle valve - the adjustable needle valve needs to cleaned periodically since it
     becomes clogged with cigarette smoke residue from the air that passes through it en
     route to the capsule filter.  The needle valve should be cleaned at least every 20
     cigarettes. To clean the valve, remove  it from its location, open the valve to a
     completely open position and clean the passage using a wire brush and soap water or, if
     available, isopropyl alcohol (IPA). Air-dry the valve before replacing it in the flow
     path.

 2.   Calibration Smoke Feed Rotameter (0-50 cc/min) — the interior channel of the rotameter
     and float need to be cleaned periodically as they become coated and/or clogged with
     smoke residue from the highly concentrated smoke aerosol flowing through the
     rotameter. The two components should be cleaned about every 20-30 cigarettes. To
     clean the rotameter, follow the procedures provided in the rotameter instruction manual.

 3.   The silica gel in the drying column will need to be replaced periodically. The indicating
     variety of silica gel should help to determine when to replace with fresh gel.

 4.   The carbon and paniculate filter cartridges inside the box enclosure should be replaced
     approximately every  100 cigarettes.  At the same time as these filters are replaced, the
     capsule filter should also be replaced.


 SMOKE GENERATOR COMPONENTS

The  following  is a list of key replaceable components within the smoke generator.  The
 manufacturer and/or vendor for each component is also listed. Note that the listings are only
indicative of the particular components used  currently in the smoke generator and are not
meant to be exclude other alternative models or manufacturers.  Replacement components
from other manufacturers or vendors may be equally suitable in some cases.
                                          88

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Component
Pump
Rotameter
Cartridge Filters
HEPA Capsule
Filter
Model Number
Model 400-1911
Models:
RMA-151-SSV
(5-50 cc/min)
RMA-150-SSV
(5-100 cc/min)
RMA-26-SSV
(0.5-5 1pm)
Models:
DFU 9933-05-AQ
DAU 9933-05-000
Model 12144
Description
Air Cadet
vacuum/pressure
pump; 1100
cu.in./min
capacity; vacuum
oil-free
Rate-Master
Flowmeters - 2"
scale; Stainless-
steel metering
valve
Particulate and
Carbon disposable
cartridge filters
HEPA Capsule
filter; 0.3 pm
Versapor; %" NPT
'inlet/outlet
Manufacturer/Vendor and
Approximate Cost
Barnant Company
28 W 092 Commercial Ave
Harrington IL 60010
1-800-637-3739
$98
Dwyer Instruments, Inc.
P.O. Box 373, Michigan City, IN 46360
(219) 872-9141
Flowmeters range from $20-$30
depending on model
Balston Filter .Systems
703 Massachusetts Avenue, Box C
Lexington, MA 02173
1-800-343-4048
Model DFU: $97/box of 10
Model DAU: $168/box of 10
Gelman Sciences
600 Wagner Road, Ann Arbor, MI
48106
Available from Fisher Scientific, Fisher
Catalog No. 09-743-28; $42
89
               •&U.S. GOVERNMENT PRINTING OFFICE: 1997 - S49-OOI/60M4

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