1996 Paso del Norte Ozone Study VOC  Measurements

 99-201

 Robert L. Scila
 VS. Environmental Protection Agency
 National Exposure Research Laboratory
 Research Triangle Park, NC 277II
 Hilary Main
 Sonoma Technology, Iric
 1360 Redwood Way, suite C
 Pelaluma, CA94954-1169
 Jose Luis Arriaga, Gerard a Martinez V.
 Institute Mexicano del Petrolco
 Eje Central Lazaro Cardenas No. 152
 Mexico City, Mexico 07730
 Abou Bakr Ramadan
Egyptian Radiation and Environmental Monitoring Network, NCKS.RC
 3 Ahamcd El-Zomoi St., 8tn District
 Nasr City, Cairo, Egypt

ABSTRACT
 Ambient air VOC samples were collected at surface air quality monitoring sites near sources of
interest, and aloft on the US and Mexican side of the border during a six week period of the 1996
Paso del Norte Ozone Study. On nine intensive operations (IOP) days. when, high ozone
concentrations were forecast, five 2-hi samples were collected at five IOP sites, three on the US
side and two on the Mexican side. Six special survey sites on the US side and two on the Mexican
side were sampled to characterize up-wind, down-wind arid other emissions. In Ciudad Juarez,
rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane and
butane fuels, and an industrial manufacturing site were sampled. Carbonyl samples were collected
at three surface sites  Carbonyl  and canister grab samples were also collected during aircraft and
hot air balloon flights. Most of the hydrocarbon samples were collected m electro-polished
stainless steel canisters xvhich were returned to laboratories for determination of C-2  to C-KH
hydrocarbonsby cryogenic preconcert ration GC-FID The carbonyl samples were collected on
DNPII impregnated C-18 Sep-Pak cartridges and analyzed by HPLC to quantify 13, C-l to C-8
species. This paper presents the spatial and temporal characteristics of VOC species
concentrations and compositions to examine the differences and similarities of the various
locations and time periods. Overall surface TNM'OC values ranged from 0.1 to 3.4 ppmC with
the highest concentrations being recorded in the morning at three vehicle-dominated sites, two in
Ciudad Juarez: and one in downtown El Paso. Toluene in El Paso samples and propane, which is'
used as a cooking and transportation fuel in Ciudad Juarez., were the most abundant
hydrocarbons. The most abundant carhonyls were acelaldehycie and acetone.

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INTRODUCTION

The measurement of atmospheric volatile organic compound (VOC) concentrations is an
important component of any large scale field study designed to characterize the air quality and
meteorological processes tliat influence the formation and transport of uzcme and ozone
precursors in a large airshed such as the El Paso, Ciudad Juarez, Sunland Park area, Seine of the
objectives of the Paso del Norte O^.one Study required the measurement of speciated  YOU? both
at the surface and aloft at several locations in the airshed to determine VOC concentration levels,
VOC composition and its relation to reactivity, and VOC concentration and composition variation
over differing diurnal and meteorological conditions. A more complete examination of the Study's
scope, objectives, and background is presented by Roberts el al. '" *

For the Paso del Norte Study four types of VOC samples were collected. On  nine intensive
operations (IOP) days, when high ozone concentrations were forecast, five, 2-hr integrated
samples were collected at five IQP sites, Ihree an ihe US side and iwo on the Mexican side.
Carbonyl samples were also collected at three of the IOP sites. VOC and carbonyl samples were
collected aloft from balloon and aircraft platforms on some of the IOP days. Supplemental or
sourcC'Speciftc suJvey sites, six on the U-S side and i\vo on the Mexican side,  were sampled on a
twice daily. 2-hr integrated sample schedule unrelated to TOP events to determine up-wind, down-
wind and other emissions characteristics. Several transportation and other  source specific grab
samples were taken mostly in CiudarJ Juarez (Table 2). With the exception of one site, the samples
were collected in electro-polished stainless steel canister which were returned to laboratories for
determination ofC-2 to C-JO-i- hydrocarbons by cryogenic preconcentrxtion gas chro-matocraphy-
flame ionization detection (GO-FID)  A continuous, automated gas chromatograph (auto-GC)was
operated at one HI Paso .site

EXPERIMENTAL METHODS

Surface ambient air samples were collected by microprocessor controlled samplers  pumping air
into passivated stainless steel spheres at sites in 01 Paso. Sunland Park and  Ciudad  Juarez. !OP
samples were collected over 2-hr periods he ginning at 06:00 , 08:00, 10:00, 12:00, and 16:00
MDT un the nine IOP days. The El Past) survey site samples were token over Iwo, 2-hr
periods on five week days in Ihe first week of the study. The Ciuuad Juarez survey sites,  also
two, 2-hr periods, and all source sites were sampled during the second week of the study,
Carbonyl samples were collected ondinitrophenylhydra^ine (DNPH) impregnated C-18 Sep-Pak
cartridge H at three surface siles. Carbonyl and canister samples were also collected during aircraft
and hoi air balloon flights. Table [ shows sampling information by site. Further sampling
      are available elsewhere.7
The canister samples were analyzed by GC-FID using two different columns. The C-2 to C-
10+ hydrocarbons were separated on a 60-m, 0.32 mm i.d. fused silica capillary column with
a 1-jum thick film of a non-polar, cross-linked liquid phase (DB 1, J&W Scientific, Rancho
Cordova, CA), Elhylcnc, acetylene,  and erhane required separation on a 30-m, 0,53 mm Ld.'
GS-Q porous pulymer upen- tubular fused silica column (J&W Scientific),  because they could
not consistently be resolved on the 60-m non-polar column. The C-2 to C-10+ hydrocarbons
were cryogenicalty preconcentrated in a 1 I -in x 1/8-in o.d. U-shaped trap filled with 60-80

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mesh glass beads cooled by liquid argon in a Dewar flask. Injection was accomplished by
switching a 6-port gas sampling valve and heating the trap with ~98°C water. In the case of
the C-2 and C-3 hydrocarbons the trap was heated by room temperature water. A
calibration/identification table of over 300 entries was used to identified peaks by retention times
adjusted to prominent reference peaks. Some are labeled by compound name and others by a
retention index identification number. The details of these analyses are published elsewhere.1
Selected samples were analyzed by GC-MSD (mass selective detection) to confirm peak
identifications. One-hr samples were obtained from the auto-GC at the Chamizal site. The
carbonyl samples were analyzed by high performance liquid chromatography (HPLC) to quantify
13, C-l  to C-8 species.4

RESULTS  AND DISCUSSION

This paper reports the analysis results of 330 canister samples collected at surface sites between
August  11 and September 21, 1996.  We also include results of auto-gc measurements at the
Chamizal site  Table 1 gives the site identification, number of samples, sampling regime, and brief
description of the site characteristics for the IOP and survey samples. The site locations and other
sampling details are given elsewhere.1'2

The total non-methane organic compounds (TNMOC)  concentration was determined by summing
all of the chromatographic peaks. It does not include the DNPII carbonyl results. This summation
is not referred to as VOC or NMVOC, because not all  of the VOC mass is recoverable and
quantifiabfe from canister sampling and gc analysis. "VOC" is a more inclusive term that will refer
to all volatile organic species including carbonyls. However, since no dryer was used prior to
analysis, the TNMOC will contain some oxygenated hydrocarbon mass. The TNMOC
distributions arc presented in Figure  1 as scatter plots of concentration versus time for the surface
monitoring sites.

Although the highest concentration sample was a 10:00 to midnight sample at the Ciudad Juarez
Police Station (the only site where night time samples were taken), generally TNMOC was
highest at the  traffic dominated Ciudad Juarez sites of 20/30 Club. Advance Transformer, Police
Station, and the El Paso Campbell site during the morning sampling periods. Four of the Ciudad
Juarez samples were over 3 ppmC and 23% were over  I ppmC. In El Paso the highest
concentration was  1.2 ppmC at the Campbell site, which is in the downtown area near the
interstate highway that bisects El Paso on an east-west  axis. Only 6% of the El Paso
measurements were over 1 ppmC  At the El Paso Chamizal site, maximum TNMOC was 2 ppmC;
however, most of the concentrations were below 300 ppbC. With the exception of 06:00-08:00 at
Winn Road, morning TNMOC at Sunland Park and the El Paso suburban sites (Dyer Road, Winn
Road, and Turf Road) was much lower, ranging from 124 to 266 ppbC, than the four high
concentration sites  Local traffic conditions at the Winn Road site were the likely cause of high
TNMOC concentrations there (683 ppmC median; range from 233 to 974 ppbC).

The paraffins, olefins, aromatics, biogenics, and unidentified species groups were determined by-
summing the compounds in these groups. The group percentages were calculated for each sample
by dividing the group sums by TNMOC. Plots of percent of TNMOC versus TNMOC for each
group are shown in Figure 2. These plots show that compositions vary widely, especially at lower

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concentrations. This is to be expected, since the distribution is over all sites and time periods and
analytical precision and accuracy deteriorate with decreasing concentration. Variability is also
increased by the mathematical certainty that a percentage change in one group must be
compensated by changes in one or more other groups. The plots also show that paraffin and
aromatic portions, from 10% to 72% and 4% to 67% respectively, vary more widely than the
olefins and biogenics. As one might expect in a  desert, environment, the biogenic species
concentrations (i.e., isoprene and a and |3-pinenes) were low

While the concentrations of unidentified species was relatively high overall, 50 to 200 ppbC, the
median unidentified fraction of 21% is typical of urban results from other studies 5'6 The median
unidentified portion of TNMOC was greater than 40% at Ascarate Park, Dyer Road and Franklin
Mountain. Other studies have shown that the unidentified portion is typically higher in afternoon
and background air samples.7 This was the case at the Ascarate Park, Dyer Road, and Franklin
Mountain sites, possibly due to aging of the air  mass.

Summations of the carbonyl compound concentrations, shown in Figure 3  as a function of time of
day, were relatively low. typically less than 15 ppbC total. However a few  measurements reached
-30 ppbC  at Winn Road and Turf Road; but only 16 ppbC at 20/30 Club. Highest concentrations
were observed at Winn Road and Turf Road during midday when TNMOC concentrations were
lowest and accounted lor a significant portion of the total carbon, up to 32%. At 20/30 Club the
maximum percentage is only 4.4%. Actolcin, crotonaldchyde, and tolualdehyde were below
detection in all samples At 20/30 Club, the most abundant species were in order of abundance
acetaldehyde, formaldehyde, acetone, and methylethylketone.  Concentrations were typically
highest during midday and changed the most with time of day for formaldehyde, acetaldehyde,
and acetone  At Turf Road, the most abundant species was acetone.  Significant concentrations of
benzaldehyde were also observed at  this site, while formaldehyde concentrations were low  At
Winn Road the most abundant species was acetone. This site also  showed relatively high
concentrations of benzaldehyde compared to 20/30 Club. Formaldehyde concentrations were low
at Winn Road.

The hydrocarbon species were ranked by median concentration. The 25 most abundant species
accounted for 70 to 80% of the TNMOC and consisted of  15 paraffins, 6 anomalies, 3 olefins, and
acetylene The 12 most abundant compounds are  plotted in Figures 4a and b as concentration
versus  site. Except  for propane and ethane the abundant compounds are associated with vehicular
emissions and gasoline.8

In Ciudad Juarez, as in Mexico City, the most abundant compound was propane.9 Concentrations
over 1  ppmC at Advance Transformer and  Police Station sites and 0.9 ppmC at 20/30 Club
suggest local sources of propane. This is not surprising since propane is used for cooking and
fuels buses in Ciudad Juarez.  The Police Station in particular was dominated by propane powered
bus traffic, which is consistent with its median propane proportion  of 21% of TNMOC. The
portion of propane  at the Zenco and the Sunland Park sites were also over 10%, indicative of
local sources  In contrast propane accounted for a median of-5%  in  Baltimore in 1996.10

Toluene, a major industrial solvent and a principal component of automobile exhaust and
gasoline,8 was the second most abundant compound in Ciudad Juarez and the most abundant
compound on the El Paso side. Concentrations  up to 221 ppbC were observed at the Police

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Station and 108 at the El Paso Campbell site. The median toluene concentration in Ciudad Juarez
was 37 ppbC compared to 25 ppbC at Campbell and 4.3 ppbC at Franklin Mountain. The median
toluene percentage of TNMOC ranged between 5.3% and 6.8% for sites dominated by morning
traffic. The highest median, 13.5% was at the Zenco industrial site.

Median concentration and  weight percent composition plots for all sites and time periods (not
shown here, sec rcf 2)  showed little change with time of day in species composition, indicating
that most sites experienced fresh emissions  during all sampling periods. This is to be expected,
since of the five TOP sites with sufficient time of day resolution, three of them, 20/30 Club,
Advance Transformer, and Campbell, were near major roadways and/or industrial sources. Matrix
scatter plots of concentration of the 20 most abundant compounds (not shown here, sec rcf. 2)
were prepared to-look at relationships between compounds. Observations from these plots by site
follow:

Chamizal: The composition was representative of other sites that are influenced by fresh motor
vehicle emissions all day; with toluene,  xylenes,  benzene, C4-C8 paraffins, and propane
dominating the profile. The dominance of gasoline vehicle exhaust was  confirmed from source
apportionment analyses of measurements at this site.11

20/30 Club: The most abundant species was propane.  Ethene was also a significant species at
this site, The motor vehicle exhaust signature is  observed by relatively good correlations among
benzene,  acetylene, cthene, propene, and several of the paraffins. The following species pairs also
appear to be from common sources: xylenes and ethylbcnzene, 2,2,4-lrimcthylpcntane and several
species associated with motor vehicle exhaust, and the butanes and pentancs (evaporative
emission  species).  Many plots at this site show outliers, indicating that  there may be more than
one source type influencing this site.

Advance Transformer: The composition was very similar to 20/30 Club with the exception of
the C2 species, there was little ethane and ethene at Advanced Transformer.  Also at this site,
isopcntane  was more abundant than toluene. Few species show strong relationships, indicating a
mixture of  sources impacting the site, consistent with the industrial setting of the site. The
following species pairs appear to be from common sources: propane and the butanes, the xylenes
and cthylbenzcnc.  Many motor vehicle exhaust  species correlate relatively well (e.g., benzene,
acetylene, cthcne, methylpentanes, hcxane, etc.). Most of the relationships with toluene show a
substantial  amount of scatter, possibly indicating a separate source of toluene (such as solvent
use). There is an interesting  "split" in the scatter plots of many of the aromatic species versus
paraffins, also suggesting the influence of different sources.  Several samples show high
concentrations of propane  and ethene.

Campbell: Toluene was the most abundant species.  The C2 species were important at this site
(similar to 20/30 Club) as was isopentane (similar tu Advanced Transformer)  At Campbell the
correlations among the species are very similar to that observed at Winn Road, most of the
species associated with  motor vehicle exhaust correlate well  Ethane and propane do not
correlate  with these species, however, indicating a separate source such as natural gas emissions
Some of the scatter in the n-butane concentrations may also be attributable to  natural gas
emissions.  The 2,2.4-trimethylpentane  concentrations correlate well with the other species in
exhaust

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Sunland Park: Propane and ethane were the two most abundant species followed by toluene.
The composition of the C3+ TNMOC at this site is similar to the Police Station, although the
concentrations were much lower.

Ascarate Park: The dominant species were the xylenes.  The contribution ofthe xylenesi
increased from the 1000-1200 to the 1200-1400 sampling period, suggesting a local source..
Typically, ambient data show a decrease in the xylene composition with time of day, because
these species are relatively more reactive than other species in the fingerprint. Also at this site,
ethene concentrations were, relatively low.

Dyer Road: TNMOC concentrations were low and the 1000-1200 and 1200-1400 sample
compositions differed significantly. The afternoon composition showed some evidence of aging
(i.e., the decrease of more-reactive species relative to less-reactive species). The composition at
this site, also differed from other  sites with the higher relative abundance of styrene, cyclohexene,
c-2-butene, and 1,3,5-trimethylbenzene.  Ethene concentrations were low compared to ethane.

Turf Road: The composition was dominated by C2-C5 paraffins, toluene, and
1,2,4-trimethylbenzene. The composition changes somewhat with time of day; however, there is
no clear indication of aging in the composition on a median basis. The source of
1,2;4-trimcthylbcnzenc should be investigated At Turf Road, the scatter plots show much weaker
correlations than observed at Winn Road, the poorer correlations (eg., benzene versus acetylene)
are indicative of more-aged air.  One exception is that the butanes and pentanes correlate very
well, indicating a common source (probably evaporative emissions).

Winn Road: As observed at Turf Road, the l,2,4-trimethylben7.ene contribution to TNMOC was
high.  Also as observed at Turf Road, the composition changes somewhat with time of day;
however, there is no clear indication of aging in the composition on a median basis. Many ofthe
species typically associated with  motor vehicle exhaust correlate well (e.g., toluene, isopcntane,
ethene, acetylene, benzene, methylpentanes, n-pentane: the xylenes, and propene). A strong
correlation is found between n-butane and isobutane probably related to an evaporative emission
source, these species also  show a reasonable correlation with the exhaust species.  The
1,2,4-trimcthylbcnzcne concentrations do not correlate very well with other aromatic species or
with the exhaust species indicating a separate source of this compound.

Franklin Mountain: Propane was the most abundant species. Styrene concentrations were
generally greater than o-xylene at this site, similar to Dyer Road. Since the site was at a television
tower facility, there may be a local source of styrene and other hydrocarbons.

CONCLUSIONS

In the El Paso-Sunland Park area TNMOC. concentrations ranged from quite low in the afternoon
at the out lying sites of Winn Road (36 ppbC) and Turf Road (39 pphC) to over 1 ppmC in the
morning at the traffic dominated  Campbell site. TNMOC concentrations at the four Ciudad Juarez
sites were much higher, ranging from 159 ppbC at Advance Transformer to over 3 ppmC at
20/30 Club, Advance Transformer and Police Station. The higher population, higher traffic
abundance and density, greater vehicle age,1? B and the widespread use of propane for cooking
and as  fuel for buses probably account for much ofthe higher TNMOC concentrations in Ciudad

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Juarez.

Propane was one of the most abundant hydrocarbons, this was expected due to the use of propane
fuel. Toluene, also an abundant hydrocarbon, was likely mostly of vehicular origin. Other
abundant hydrocarbons representative of vehicular related sources were, pcntanes, xylenes,
butanes, benzene, ethylene, and acetylene Some sites in El Paso and Ciudad Juarez showed
evidence of other VOC sources such as industrial solvents( e.g., xylenes at Ascarate park, styrene
at Franklin Mountain, and 1,2,4-trimethylbenzene at Turf Road).

Cafbonyl compounds at the suburban sites were relatively low, ranging from 0.2 to 32 ppbC with
highest concentrations midday. Since carbonyl compounds are both directly emitted and formed
as photochemical products of reaction, the higher concentrations midday suggest the probable
importance of photochemistry as a source of carbonyls at these sites. Concentrations were lower,
ranging from 4 to] 6 ppbC and did not vary much at the 20/30 Club, a high VOC,-direct emissions
source site.

The range of TNMOC at the background site on Franklin Mountain were relatively high for a
downwind site, ranging from 128 to 250 ppbC. The concentrations and composition of VOC at
this site, although much lower than the downtown Campbell site, showed the impact of urban
emissions

ACKNOWLEDGMENTS

The authors wish to thank the many field and laboratory personnel whose hard work made this a
successful study, including those from Los Alamos National Laboratory, Sonoma Technology,
Inc., AeroVironment, Desert Research Institute, Environmental Defense Fund, University of
Texas at El Paso, University of Utah, New Mexico State University, Texas Natural Resource
Conservation Commission, El Paso City-County Health and Environmental District, Direccion
Municipal de Ecologia-Ayuntamiento dc Juarez, and the New Mexico Environment Department.

DISCLAIMER

The information in this document has been funded wholly or in part by the United States
Environmental Protection Agency under Contract 68-D3-0030 to Science Applications
International Corporation. It has been subjected to agency review and approved for publication.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.

REFERENCES

I.    Roberts, P.; MacDonald, C ; Main, II., Dye, T.; Coe, D.; Haste, T. Analysis of
      Meteorological and Air Quality data for the 1996 Paso del Norte Ozone Study, Report
      STI-997330-1754-FR, Sonoma Technology., Inc., Pctaluma, CA, EPA contract 68-D3-
      0030, September  1997

2     Roberts, P ; Coe,  D ; Dye, T.; Ray. S; Arthur, M. Summary of Measurements Obtained
      During the .1996 Paso del Norte Ozone Study, Report STI-996191 -1603-FR, Sonoma

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       Technology, Inc., Petaluma, CA, EPA contract 68-D3-0030, September 1996

3.     Seila, R. Retention Time Precision in Gas Chromatographic Methods Employing
       Cryogenic Preconcentration for Analysis of Whole Air Samples, In Proceedings of the
       1995 U.S. EPA/A&WMA International Symposium on Measurement of Toxic and
       Related Air Pollutants, VIP-34, May 1995, pp 135-MO.

4.     Zielinska, B. Paso del Nortc Pilot Border Study of Ozone Precursors and Air Toxics,
       Draft final report prepared for TRC Environmental Corporation, Chapel Hill, NC by
       Desert  Research Institute, Reno, NV, EPA contract 68-D-0029. work assignment 2-105,
       February 1996.

5.     Main, H.; Roberts, P.  Validation and Analysis of the Lake Michigan Ozone. Study
       Ambient VOC Data, Report prepared for the Lake Michigan Air Directors Consortium,
     . DCS Plaincs, IL by Sonoma Technology, Inc., Petaluma, CA, STI-902I7-1352-DFR,
       1993.

6.     Lurmann, F..; Main. II.II. Analysis of the Ambient VOC Data Collected in the Southern
       California Air Quality Study, Report prepared for the California Air Resources Board.
       Sacramento, CA by Sonoma Technology, Inc., Petaluma, CA, STi-99120-1161-FR,
       Contract No. A823-13, 1992

7.     Lindscy, C.; Dye, T., Main, H., Korc, M; Blumenthal, D , Roberts, P., Ray, S.; Arthus, M..
       Air quality and Meteorological Data Analyses for the 1994 NARSTO-Northeast Air
       Quality Study, Report prepared for the Electric Power Research Institute, Palo Alto, CA
       by Sonoma Technology, Inc., Petaluma,  CA, STI-94362-1511-F, 1997.

8.     Conner, T., Lonneman, W., Seila, R. J. Air & Waste Manage. Assoc. 1985, 45, 383-39-1.

9.     Seila, R.; Lonneman, W.; Ruiz, M., Tejeda, J. VOCs in Mexico City Ambient Air, In
       Proceedings of the 1993 U.S. EPA/A&WMA International Symposium on Measurement
       of Toxic and Related Air Pollutants, EP A/600/A63/024, VIP-34, May 1993, pp 616-621.

10.     Main, H., Hurwitt, S., Roberts, P. Characteristics Of Volatile Organic Compounds In
       The Mid-Atlantic. Region Final  report prepared for MARAMA, Baltimore, MD by
       Sonoma Technology Inc , Petaluma, CA, STI-998481-1869-FR, March 1999.

11.     Fujita, R Hydrocarbon Source Apportionment for the 1996 Paso del Norte Ozone Study,
       Report, Desert Research Institute, Reno, NV, EPA contract 68-D3-0030, March  1998.

12.     Goir/,alc/.-Ayala S (1998) Institute Municipal de Investigation y Plancacion Progress under task 1:
       editing/analysis of the on-board transit count database. Technical memorandum to Ken Mora (project
       director, TxDOT), Tack Graham (TxDOT), andDavid Pearson (TTI). January 9. 1996 reported
       population of Juarez  1,065,200

13.     U.S. Census Bureau,  County Estimates: 1990 to  1997  Annual Time Series of Population
       Estimates, http:/Avww.census gov/popular.ion/estimates/county/co-97-4/97C4_4S.txt,
       March 3,  1999  July 1,  1996 estimated population of El Paso County: 685,018.

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TABLES
                   Tablet. Paso del Norte VOC sampling locations.
Site
Delmex
Zenco
Police Station
Advance
Transformer
20/30 Club
Campbell
Franklin Mts
Sunland Park
Ascarate Park
Dyer Road
Turf Road
Winn Road
Chevron refinery
N"
2
->
10
50
51
48
9
10
10
10
51
47
10
Sampling Period u
5-min grab samples
2-hr samples taken on 2 days
during second week of study
6-8, 10-12 on 5 days during
second week of study
2-hr samples beginning at 6, 8.
10, 12, 16 on IOP days
2-hr samples beginning at 6, 8,
10, 12, 16 on IOP days
2-hr samples beginning at 6, 8.
10, 12, 16 on IOP days
6-8, 8-10 on 5 days during first
week of study
6-8, 8-10 on 5 days during first
week of study
10-12, 12-14 on 5 days during
first week of study
10-12, 12-14 on 5 days during
first week of study
2-hr samples beginning at 6, 8,
10, 12, 16 on IOP days
2-hr samples beginning at 6, 8,
10, 12, 16 on IOP days
2-hr samples, 2 per day over 5
days during second week
Description
Ciudad Juarez industrial area
Ciudad Juarez survey site:
manufacturing area near airport
Ciudad Juarez survey site: near
downtown, high traffic area
Ciudad Juarez IOP site:
industrial manufacturing area
with morning & evening traffic
Ciudad Juarez IOP site:
commercial, suburban, near
major thoroughfare
El Paso IOP site downtown
very near interstate highway
F.I Paso survey, boundary site on
mountain north of El Paso
Sunland Park, MM survey site: at
city offices downtown area
El Paso survey site: park & golf
course
F.I Paso survey site, suburban
location
El Paso IOP site, suburban
location
El Paso IOP site, suburban
location
El Paso source site, oil refinery
" N=number of samples. *
Operating Period.
Times arc 24-hr, Mountain Daylight Time (MDT). IOP=Intensive

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Table 2. Paso del Norte VOC special source samples.
Site
Ciudad Juarez traffic
Ciudad Juarez propane
buses
Ciudad Juarez paint
shop
Ciudad Juarez propane
and natural gas
El Paso propane
Number of
Samples
2
2
4
7
2
Sampling Period
~5-min samples taken
from car in moving
traffic
-5-min samples taken
from car in bus traffic.
1 grab sample taken
from bus tailpipe
- 5 -mi n samples
canister grab samples
canister grab samples
Description
samples taken near
downtown Ciudad Juarez
samples taken downtown
Ciudad Juarez near bus
station
samples from small auto
body paint shop
1 natural gas and 2 propane
distributors
2 propane distributors
                                                                10

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FIGURES
        Figure 1. Distribution of TNMOC as a function of time of day by site.
   O
   o
   r-
       3000
       1000
       3000

       1000
/


—
Winn Road
i 8 0 o o ° 1
Zenco

Dyer Road
o o ; § 6
Advance Transforms
r Turf Road
O :
Q
O
O £}
§sl @i
20/30 Club
o
o ° I8

080 0 $ g
Campbell J

• .. 18
Franklin Mts
© 0
Ascarate Park
€1 @
Sunland Park


ie
uarez Police Static
o
o
o
°8
0 00
                       i  I  I  I
               1012161820226 8
 !  :  . !  I   !  ; '    I  I  !  I  I  I  I  I
10121618202268   10121618202268
                                Hour of day, MDT
                                                                     11

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            Figure 2. Distribution of compound groups versus concentration.
    30
o
o
0)
o
t_
CD
Q_
    70
    30
                 Unidentified
    70  ~
median=21%
                   Olefins
                  median=12%
                  Paraffins
                          Biogenics
                                           median=0.3%
                                                 OOQDQ
                          Aromatics
                       9)  o
                                               median=20%
 ,  median=43%
'
              1000
        3000


          TNMOC, ppbC
                                                            12

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               Figure 3. Distribution of total carbonyls by time of day
      30
o
.a
Q.
Q.
20
03

O
CO
      10
       0
         D
                6
                                  :	1

                                  I...J
                            n
                          Hour of day, MDT
                8    10    12    16    18   20
                                               O    20/30 Club

                                               A    Turf Road

                                               n    WinnRoad
                                                                   13

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Figure. 4a. Distribution of the six most abundant hydrocarbons by site. The x-axis range is
            not large enough to show all of the point for propane (see text).
                                     0   100  200

                                           I	L
C/5
           Zenco
      Winn Road
       Turf Road
     Sunland Park
     Police Station
     Franklin Mts
       Dyer Road
        Campbell
    Ascarate Park
         Advance
       20/30 Club
       Zenco
   Winn Road
    Turf Road
 Sunland Park
 Police Station
 Franklin Mts
   Dyer Road
    Campbell
Ascarate Park
     Advance
   20/30 Club
           Zenco
      Winn Road
       Turf Road
     Sunland Park
     Police Station
     Franklin Mts
       Dyer Road
        Campbell
    Ascarate Park
         Advance
       20/30 Club
n-propane
CH>
OTDOES O O
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isopentane
o
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n-pentane
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toluene
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C
CJSSEDO
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ethane
©
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OTXET;
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(S)
EB
OS53Q : C
                    I   ;  I   I  :   I

                    0    100  200

                              Cone., ppbC
                                                                          14

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 Figure 4b. Distribution of the second six most abundant hydrocarbons by site.
                                    0    100  200
                                                  I
_CD

00
          Zenco
      Winn Road
       Turf Road
    Sunland Park
    Police Station
     Franklin Mts
      Dyer Road
       Campbell
    Ascarate Park
        Advance
      20/30 Club
       Zenco
   Winn Road
    Turf Road
 Sunland Park
 Police Station
  Franklin Mts
   Dyer Road
    Campbell
Ascarate Park
     Advance
   20/30 Ciub
          Zenco
      Winn Road
       Turf Road
    Sunland Park
    Police Station
     Franklin Mts
      Dyer Road
       Campbell
    Ascarate Park
        Advance
      20/30 Club

n-butane
o
OS)
oo
©GOT} O GO
O G
(35
QD
 O
benzene
o
CEO
O
CO
c
o
o
«*)
o
•WED
aBOO
2-methylpentane 1
o
o
o
SSS3D O
O
o
«B
O
«KT,
OO&)

acetylene
o
OJ
as
(CX'KOSS
CD
O
0 ;
®EP) COO

ethene
0
OEED
O
4Bt
O3QS»Di
©
O
(S8E
O
fl» CJ
CHfiD O
,2,4-trimethylbenzeri
o
ess
o
SKBO
0
0
i»
0
8HFEB O
one
                   1  I   I

                   0   100
                          I

                         200

                          Cone., ppbC
                                                                     15

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          NERL-RTP-0-654
TECHNICAL  REPORT DATA
   1.  REPORT NO.
         600/A-99/068
                                3.RECIPIENT'S ACCESSION NO.
   4.  TITLE  AND SUBTITLE
                                                                        5.REPORT DATE
   1996 Paso del Norte Ozone Study VOC Measurements
                                                                       6.PERFORMING ORGANIZATION CODE
  7. AUTHOR(S)

  Authors) Robert L. Seila, Hilary Main, Jose Luis Arriaga, Gcrardo Martinez,
  Abou Bakr Ramadan
                               8.PERFORMING ORGANIZATION REPORT NO.
  9. PERFORMING ORGANIZATION NAME AND ADDRESS

  National Exposure Research Laboratory
  Office of Research and Development
  U.S. Environmental Protection Agency
  Research Triangle Park, NC 27711
                               10.PROGRAM ELEMENT NO.
                               11. CONTRACT/GRANT NO.
  12. SPONSORING AGENCY NAME AND ADDRESS

  National Exposure Research Laboratory
  Office of Research and Development
  U.S. Environmental Protection Agency
  Research Triangle Park, NC 27711
                               13.TYPE OF REPORT AND PF.RIOD COVERED
                               14. SPONSORING AGENCY CODE
  15. SUPPLEMENTARY NOTES
  !6. ABSTRACT
  The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources
  of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported.
  Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify
  13, C-l to C-8  species. Whole air samples were collected^in electro-polished stainless steel canisters which were returned to
  laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography
  with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust,
  automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal
  characteristics  of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from
  0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Ciudad
  Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation
  fuel in Ciudad  Juarez, were the most abundant hydrocarbons.
  17.
                                      KEY WORDS AND DOCUMENT ANALYSIS
                       DESCRIPTORS
                 b. IDENTIFIERS/ OPEN ENDED
                 TERMS
                                                                                         c.COSATI
  18. DISTRIBUTION STATEMENT

  RELEASE TO PUBLIC
2220-1
                 19. SECURITY CLASS (This Report)

                 UNCLASSIFIED
                                                                                         21.NO. OF PAGES
                                                         20. SECURITY CLASS (ITus Page)

                                                         UNCLASSIFIED
                                                22. PRICE

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