&EPA
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 15027
Las Vegas NV 89114
EPA 600 4-80-002
January 1980
Research and Development
Lead Particles in
the Great Smoky
Mountains Biosphere
Reserve
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad categories
were established to facilitate further development and application of environmental
technology. Elimination of traditional grouping was consciously planned to foster
technology transfer and a maximum interface in related fields. The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL MONITORING series.This series
describes research conducted to develop new or improved methodsand instrumentation
for the identification and quantification of environmental pollutants at the lowest
conceivably significant concentrations. It also includes studies to determine the ambient
concentrations of pollutants in the environment and/or the variance of pollutants as a
function of time or meteorological factors.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161
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EPA-600/4-80-002
January 1980
LEAD PARTICLES IN
THE GREAT SMOKY MOUNTAINS BIOSPHERE RESERVE
by
G. B. Wiersma, C. W. Frank*, K. W. Brown, and C. I. Davidson**
Exposure Assessment Division
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89114
*C. W. Frank - University of Iowa
**C. I. Davidson - Carnegie-Mellon University
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring Systems
Laboratory—Las Vegas, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
ii
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FOREWORD
Protection of the environment requires effective regulatory actions
based on sound technical and scientific data. The data must include the
quantitative description and linking of pollutant sources, transport
mechanisms, interactions, and resulting effects on man and his environment.
Because of the complexities involved, assessment of exposure to specific
pollutants in the environment requires a total systems approach that
transcends the media of air, water, and land. The Environmental Monitoring
Systems Laboratory at Las Vegas contributes to the formation and enhancement
of a sound monitor!ng-data base for exposure assessment through programs
designed to:
• develop and optimize systems and strategies for moni-
toring pollutants and their impact on the environment
• demonstrate new monitoring systems and technologies
by applying them to fulfill special monitoring needs
of the Agency's operating programs
This study was conducted to determine the concentrations and physical
characteristics of lead particulates in remote areas in the Great Smoky
Mountains National Park. The study is part of the development of a pollutant
monitoring system for biosphere reserves. The information should be useful to
EPA scientists, land management persons and international agencies concerned
with global pollution. For further information contact the Exposure
Assessment Research Division of this Laboratory.
f/t-^'^f^*-
/ >/
George B. Morgan
Director
Environmental Monitoring Systems Laboratory
Las Vegas
m
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ABSTRACT
Air monitoring using 0.45-micrometer Millipore® filters at eight remote
sites in the Great Smoky Mountains National Park has shown that lead
particulates are contributing to the contamination of this designated
biosphere reserve. Analytical results of these filters by atomic absorption
spectrophotometry, x-ray fluorescence, and scanning electron microscopy showed
that lead air concentrations varied from a high of 140 ng/m3 to a low of 19
ng/m3.
The lead particles were primarily spherical in shape, measuring less than
one micrometer in diameter. The chemical composition of these
submicrometer-sized particles was predominately lead associated with small
amounts of sulfur. The lead particulates that were greater than 1.0
micrometer in diameter were not spherical in shape and contained other
elements such as iron, calcium, magnesium, and silicon.
The spherical shape of the lead particulates indicates that the moieties
were formed by high temperature processes, such as by internal combustion
engines. Also, the small particulate size may indicate long range transport
and subsequent deposition from urban and/or industrialized areas.
©Registered trademark
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INTRODUCTION
In September 1977, a pilot study was- initiated in the Smoky Mountains
National Park to begin the development of a pollutant-monitoring system for
biosphere reserves. Smoky Mountains National Park is a designated biosphere
reserve and this program has been described in detail by Franklin (1977). The
project was a cooperative study between the U.S. Environmental Protection
Agency and the U.S. Park Service.
This study discovered high lead concentrations in forest litter (Wiersma,
Brown and Crockett, 1977). Concentrations of lead ranged from about 250 ug/g
at lower elevational sites to over 450 pg/g at the high altitude site. These
levels matched the data reported by Reiners, Marks and Vitousek (1975) for the
White Mountains of New Hampshire. They found lead levels in the hundreds of
parts per million range in forest litter. They also found an increase of lead
residues in litter with altitude up to the Krummholz, where there was a slight
decrease in lead concentration. They concluded that the increased lead
concentration probably was the result of long-range transport processes.
The source of the lead in the Smoky Mountains study was unknown.
Vehicular traffic in the Park is heavy and could be a local source. However,
long-range transport and lead sources remote from the Park could also
contribute to the lead burden.
That lead could be transported over long distances is widely reported in
the literature. Hirao and Patterson (1974) report that lead had contaminated
a remote site, Thompson Canyon, in the High Sierra of California. Zoller,
Gladney and Duce (1974) reported lead atmospheric particulates collected at
the South Pole were highly enriched compared to what could be expected from
normal crustal weathering. Murozumi, Chow and Patterson (1969) present
evidence of increasing residues of lead in Greenland snow and attributed this
increase to advent of leaded automobile fuels. Finally, Elgmork, Hagen and
Langeland (1973) found levels of lead in snow in Norway of up to 98 ug/1.
They also found high sulphur levels in the form of sulphate of up to 19 mg/g.
They concluded that these pollutants had been transported to Norway and
deposited via precipitation. The sources were thought to be the large
industrial and urban complexes of central and western Europe.
A second study was undertaken in May of 1978 to determine lead
concentration in the atmosphere over ranote areas of the Park and to
characterize lead particulates by size and chemical composition. We also
hoped to determine, if possible, the source of lead in the Smoky Mountains.
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METHODOLOGY
A comprehensive sampling program was carried out in the Smoky Mountains
National Park in May 1978. As part of the program, special efforts were made
to collect air particulate samples in remote areas of the Park. The filters
would then be analyzed by three independent techniques: atomic absorption
(AA) spectroscopy; x-ray fluorescence techniques; scanning electron microscopy
(SEM) techniques for particle size, shape, and surface composition.
Two remote sites were established in the Park. These were the Silers Bald
site (site 12) and Sawteeth site (site 11) (Figure 1). Criteria for the
selection of these sites were:
1. At least 8 kilometers from the nearest road that had any
automobile traffic
2. located at as high an elevation as possible
3. located in a cleared area whose diameter was at least five
times the height of the surrounding forest.
The two sites chosen met these criteria.
In addition, eight other air monitoring sites were established. However,
these'were coordinated with vegetation and soil sampling and did not meet the
requirements mentioned above. All were located under forest canopy. Only
those for which filters were analyzed for lead are shown on Figure 1. All the
sites that were located under the forest canopy were a minimum of 3 kilometers
from a road where automobile traffic was permitted, most were considerably
further away, up to 10 kilometers.
Hi 1 lipore® filters (0.45 ym), were purchased already mounted and sealed in
plastic holders. The plastic filter holders were not opened until the air
monitoring system was ready to be turned on in the field. Millipore filters
were set up in groups of four at each site. In general this allowed one
filter for x-ray analysis, another filter for SEM analysis, a third filter for
AA analysis and the fourth to be archived. Unopened filters, that went into
the field, were submitted for analysis along with the opened filters.
Table lisa summary of the sites, sampler flow rates, length of time
sampled, volume of air sampled, type of analyses, and site description.
An air sampling system was specifically designed to meet the needs of this
project. Local power sources were not available where the air samplers were
to be operated. The use of yasoline-powered generators was ruled out because
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• Sampled Spring, 1978
Figure 1. Location of air sampling sites in the Great Smoky Mountains National Park,
May/June 1978.
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TABLE 1. SUMMARY OF AIR SAMPLING SITES IN THE GREAT SMOKY MOUNTAINS NATIONAL PARK*
Site
No,
12
11
1
3
4
5
6
8
--
Name
Silers Bald
Sawteeth
Fi sh Camp
Prong
Low altitude
Ramsey Cascade
High altitude
Ramsey Cascade
Low altitude
No land Creek
High altitude
No! and Creek
High altitude
Rich! and Mt.
Las Vegas, NV
Site Description
Open, remote site 8 kilo-
meters from nearest road
Open, remote site 8 kilo-
meters from nearest road
Logged hardwood forest--
North slope
Unlogged hardwood forest--
North slope
Unlogged hardwood forest--
North slope
Logged hardwood forest- -
South slope
Unlogged hardwood forest--
South slope
Unlogged hardwood forest--
South si ope
Urban environment
Number of
hours
Operated
188.5
168.0
69.5
167.0
162.5
142.5
144.5
142.0
120.0
Average
flow rate
(1pm)
1.0
1.0
1.0
1.0
0.9
1.0
1.0
1.0
1.0
Total air
sampled
(m5)
11.3
10.1
4.2
10.0
8.8
8.6
8.7
8.5
7.2
Types of Analyses
x-ray SEM AA
X X
X X
X X
XXX
XXX
X X
X X
X X
X X
samples were collected at all stations in the Park between May 21 and 31, 1978.
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of contamination problems and propane gas generators were not used because of
logistics. Therefore, a portable, battery-operated system was needed. This
system has been described in detail by Brown et al, 1979. Basically it is a
DuPont air pump (Node! P-40QOA) operated by a specially designed battery pack
using Gates rechargeable sealed acid batteries. Air flow was controlled by
Dwyer adjustable rotameters connected to the Millipore filters and DuPont pump
by amber latex laboratory tubing. As can be seen from Table 1, these pumps
operated continuously for up to 188 hours. Except for one site, flow rates
held constant throughout the entire sampling time. Of the 10 stations
established, only 2 failed during the sampling period. One site appeared to
have been tampered with, either by a human or wild animal, and the other site
showed no obvious reasons for the failure to operate. It is suspected that
the problems were in the power supply since both pumps operated normally when
attached to a different battery pack.
Filters were collected, resealed and submitted for analysis. The x-ray
fluorescence technique used was as described by Jaklevic et al. (1973) and
Jaklevic, Loo and Goulding (1976). Scanning electron microscope analyses were
used to determine particle size and composition. Atomic absorption
spectrometric analyses were done at Carnegie-Mellon University.
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RESULTS AND DISCUSSION
Tables 2 and 3 show results of the x-ray fluorescence and atomic
absorption spectrometric analyses, respectively. Atomic absorption analyses
are for two different filters exposed simultaneously at each site. Results
for lead show reasonable agreement between the two methods. The value of lead
in the blanks was divided by the total lead in each filter as a measure of
reliability of the handling and processing of the samples.
TABLE 2. SUMMARY OF RESULTS OF X-RAY FLUORESCENCE ANALYSES*
Site Number (Results in ng/m3)
Element 1 3 4 5 6 8 Las Vegas
Titanium
Manganese
Iron
Lead
ND**
ND
ND
ND
12
28
80
ND
19
ND
112
68
14
39
182
88
ND
46
184
103
18
36
179
89
128
ND
1690
530
* cross check samples indicate precision of reported data to be:
Ti = ± 30%; Mn = ± 25%; Fe = ± 50%; Pb = ± 15%.
** none detected.
TABLE 3. ATOMIC ABSORPTION ANALYSES FOR LEAD (ng/m3)
Site
1
3
4
5
6
8
11
12
Average*
(ng/m3)
19
40
42
140
120
94
58
51
± Average deviation
(%)
23
12
13
20
26
23
55
13
Blank -r- Total Sample
0.74
0.36
0.37
0.16
0.19
0.22
0.32
0.28
* Blank values already subtracted
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The absence of detectable levels for site 1 by x-ray fluorescence may be
explained by the low total volume of air sampled at that site. Apparently the
residue levels for lead at site 3 were below or at the detection limits for
the x-ray fluorescence technique.
It is interesting to note that sites 5, 6, and 8, located on the south
slopes of the Park, all have a higher lead concentration than sites 1, 3, and
4, located on the north slopes of the Park. Wind data were obtained from the
National Climatic Center in Asheville, North Carolina. The data were from a
mountain top site 96 kilometers due east of the Great Smoky Mountains National
Park. The winds during the sampling period were always out of the south or
west. If pollutants were moving into the park from distant sources, then the
wind data along with the data for elevated lead levels on the southern slopes
of the Park would tend to be mutually supportive.
Zoller, Gladney and Duce (1974) reported lead concentration in air at the
South Pole as 0.63 ng/m3. They also reported that lead had a very high
enrichment factor for air when compared to expected levels based on normal
crustal weathering. Adams et al. 1977, measured lead concentration in air
near the top of Chacaltaya Mountain in Bolivia. The station is located
approximately 25 km north of LaPaz at an altitude of 5220 m. Lead
concentrations measured by x-ray emission on 0.4 pm Nucleopore® filters showed
lead, levels ranging from 4.0 to 7.1 ng/m3. Chow and Earl report lead levels
in air at the Mount Laguna station at the San Diego State College Astronomical
Observatory about 45 miles east of San Diego averaged approximately 50 ng/m3.
Moyers et al., 1977, reported lead levels at a desert site about 60 miles
southeast of Tuscon to be 67 ng/m3.
Urban levels are much higher. Dzubay and Stevens (1975) report lead
levels for St. Louis to be about 460 ng/m3. Davidson (1977) reports
atomospheric lead concentrations for the Los Angeles area of 1160 ng/m3 to
1254 ng/m3. Lioy, Wolff and Kneip (1978) reported average lead concentrations
in air for New York City of 1388 ng/m3.
The levels from the Smoky Mountain samples varied from 40 ng/m3, typical
of a site 40 to 60 miles from a large urban area, to 140 ng/m3, which is high
for a supposedly pristine background area.
Three Mil lipore filter pads taken from different locations in the Park
were analyzed by SEM. Of the 669 particles characterized, 19 were found to
contain lead as the predominant element on the particle surface. This is
about 3 percent of the total number of particles characterized. As a crude
analogy, Chow and Earl (1970) reported that lead aerosols made up 3 to 4
percent of the total suspended particulate matter in downtown San Diego. A
summary of the physical and chemical properties is presented in Table 4.
In general most lead particles were spherical , were less than 1 micrometer
in diameter, and contained lead as the major surface constituent with small
.amounts of sulfur. The majority of the lead-containing particles larger than
1 ym were not spherical and contained other elements (Fe, Ca, Mg, Si) in
addition to lead and sulfur.
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TABLE 4. SUMMARY OF LEAD PARTICLES CHARACTERIZED BY SCANNING
ELECTRON MICROSCOPY
Site Name
Particle Size/Shape
(ym)
Elemental Makeup
Silers Bald
(Site 12, Total particles
examined =270)
5, Rectangle
1.5, Sphere
1.0
0.8
1.0
1.0
0.8
1.0
1.5
0.5
1.0
, Sphere
, Sphere
, Sphere
x 1.5, Oval
, Sphere
, Sphere
, Sphere
, Sphere
, Sphere
Pb, S
(Mg, Ca, Fe)*
Pb, S
(Mg, Ca, Fe)*
Pb, S
Pb, S
Pb, S
Pb, S
Pb, S
Pb, S
Pb, S, Ba
(Ca, S}*
Pb, S
Pb, S
Sawteeth Site
(Site 11, Total particles
examined = 135)
0.5, Sphere
0.6 x 1.0 Oblong Sphere
0.5 x 0.8, Oval
Pb, S
(Ca, K, Si)*
Pb, S
Pb, S
Ramsey Cascade
(Site 3, Total particles
examined = 264)
1.5, Sphere
1.0, Sphere
0.8, Sphere
0.6 to 0.7, Sphere
1.5 to 2.5,
Pb, S**
(K, Ca, Si, Fe)*
Pb, S
Pb, S
Pb, S
Pb, S
* trace constituents
** Sulphur questionable
The spherical nature of the lead particulate indicates that the moieties
were formed via some high temperature process. Although other lead sources
are possible, we presume that the most probable source of the lead is
automotive exhaust. This agrees with previous observations using light
microscopy to analyze particulate from air samples collected by 4-stage
differential samplers (Mammerorella, 1973).
In addition it has been observed that two types of lead-containing
particulate are emitted from automotive exhaust (Keyser, Natusch, Evans, and
-------
Linton, 1978). The first is described as being irregular in shape, greater
than 10 pm in cross section and containing Fe, Pb, S, Br, and Cl with varying
amounts of Ca and Si. The second type is represented by spherical particles
of less than 1 pm in diameter and contains Pb, Br, and Cl. Although the
halogens were not found in any of the particulates studied in the present
work, the two types of particles are represented with the majority being less
than 1 urn. Evidence exists in the literature that the halogens (Br) decrease
as the transport distance and exposure time increases. In a study in Europe
Rentschler, (1977) found Br/Pb ratios in larch needles that ranged from 1.3
(221 ygNo/g: -289 ygBr/g) for highly traveled areas to 0.4 (-11.4 ugNo/g:
4.3 pgBr/g) for reasonably remote areas.
No bromine was detected by the SEM method in the samples collected in the
Smoky Mountains. The SEM analyses of particle size indicated that most of the
lead particles were one micron or less in diameter. The absence of bromine
and a small particle size would indicate that the particles had moved over
long distances. However, not enough lead particles were examined to allow a
statistically meaningful frequency distribution to be constructed. Also, no
climatological data were collected. Therefore, the question of whether lead
contamination is coming from within the Park (heavy automobile traffic) or
from outside the Park (upwind urban/industrial centers) remains unanswered.
It should be mentioned that Elias et al., (1978), using cascade impactors,
examined size distributions of airborne lead and other species in a remote
area of the Sierra Nevada mountains. They found only 11% of the airborne lead
particles were larger than 4 pm aerodynamic diameter.
Another feature of these particles of Table 4 is the constant association
of sulphur with lead. The exact makeup of the lead/sulphur chemical compound
(the x-ray backscatter pictures indicate a uniform distribution of lead and
sulphur in lead particles) is unknown. However, there is some evidence in the
literature that lead particles act as a surface for the conversion of S02 to
sulfate. Moyers et al. (1977) calculated the correlation coefficient for lead
and sulphate (SO^2") for urban areas of 0.49. This same pairing had a
correlation coefficient of 0.78 for samples collected at a site 60 miles
southeast of the urban area. However, we are not suggesting that the compound
is lead sulphate. At this time there is not enough information to make this
statement.
All the data collected so far indicate lead in concentrations relatively
high for a background area, having a high temperature combustion process as
their source and a size distribution favoring long-term transport.
-------
REFERENCES
Adams, F., R. Dams, L. Gusman, and J. W. Winchester. Background Aerosol
Composition on Chacaltaya Mountain, Bolivia. Atmospheric Environment
ll.:629-634. 1977.
Brown, K. W., G. B. Wiersma and C. W. Frank. A Battery Operated Air Sampler
for Remote Areas. EPA-60Q/4-79-071. 1979.
Chow, T. J. and J. L. Earl. Lead Aerosols in the Atmosphere: Increasing
Concentrations. Science 169:577-580. 1970.
Davidson, C. I. The Deposition of Trace Metal-Containing Particles in the Los
Angeles Area. Powder Technology 18:117-126. 1977.,
Dzubay, T. G. and R. K. Stevens. Ambient Air Analysis with Dichotomous
Sampler and X-ray Fluorescence Spectrometer. Environ. Sci. & Technol.
9^(7):663-668. 1975.
Elgmork, K., A. Hagen, and A. Langland. Polluted Snow in Southern Norway
During the Winters 1968-1971. Environ. Pollut. 1:41-52. 1973.
Elias, R., Hirao, Y., Davidson, C. and Patterson, CA, "Input-Output Mass
Balances of Metals in Thompson Canyon and the Impact of Accumulated Metals
on^its Biomass," manuscript in preparation, to be submitted for
publication 1978.
Franklin, J. F. The Biosphere Reserve Program in the United'States. Science
195:262-267. 1977.
Hirao, Y. and C. C. Patterson. Lead Aerosol Pollution in the High Sierra
Over-Rides Natural Mechanisms Which Exclude Lead from a Food Chain.
Science 184:989-992. 1974.
Jaklevic, J. M., B. W. Loo, and F. S. Goulding. Photon Induced x-ray
Fluorescence Analysis Using Energy Disperive Detector and Dichtomous
Sampler. X-Ray Fluorescence Analysis of Environmental Samples Symposium,
Chapel Hill, NC (January 26-28, 1976).
Jaklevic, J. M., F. S. Goulding, B. V. Jarrett, and J. D. Meng.
Applications of X-ray Fluorescence Techniques to Measure Elemental
Composition of Particles in the Atmosphere. 166th American Society
Meeting on Analytical Methods Applied to Air Pollution Measurements,
Dallas, TX. April 8-13, 1973.
10
-------
Keyser, T. R., D, F. S. Natusch, C. A. Evans, and R. W. Linton.
Characterizing the Surface of Environmental Particles. Envir. Sci.
Technol. 12.(3):769. 1978.
Lioy, P. J., G. T. Woff, and T. J. Kneip. Toxic Airborne Elements in the New
York Metropolitan Area. Jour. Air Pollution Control Assoc. _28(5): 510-512.
1978.
Hammerorella, L. Air Pollution Due to Lead from Motor Vehicles. Rass. Chim.
25(4):301. 1973.
Moyers, J. L., L. E. Ranweiler, S. B. Hopf, and N. E. Korte. Evaluation of
Particulate Trace Species in Southwest Desert Atmosphere. Environ. Sci.
and Technol. U_:789-794. 1977.
Murozumi, M., T. J. Chow, and C. Patterson. Chemical Concentrations of
Pollutant Lead Aerosols, Terrestrial Dusts and Sea Salts in Greenland and
Antarctic Snow Strata. Geochmica et Cosmochimnca Acta 33:1247-1294.
1969.
Reiners, W. A., R. H. Marks, and P. M. Vitousek. Heavy Metals in Subalpine
and Alpine Soils of New Hampshire. Qikos 26(3):264-274. 1975.
Rentschler, I. The Pb Content of Larch Needles at Locations with Different
Density of Traffic. Proc. Int. Clean Air Congr., 4th, 1977, 559, Ed.
Kasuga, Susumu, Suzuki, Noboru, Yamada, 1.
Wiersma, G. B., K. W. Brown, and A. B. Crockett. Development of a Pollutant
Monitoring Systan for Biosphere Reserves and Results of Great Smoky
Mountains Pilot Study. In: 4th Joint Conference on Sensing of
Environmental Pollutants. New Orleans, LA. pp. 451-456. 1978.
Zoller, W. H., E. S. Gladney, and R. A. Duce. Atmospheric Concentrations and
Sources of Trace Metals at the South Pole. Science 183:198-200. 1974.
11
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TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1. REPORT NO.
EPA-600/4-80-002
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
LEAD PARTICLES IN THE GREAT SMOKY MOUNTAINS
BIOSPHERE RESERVE
5. REPORT DATE
January 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
G. B. Wiersma, C, W. Frank, C. I. Davidson and
K. W. Brown
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Monitoring Systems Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
10. PROGRAM ELEMENT NO.
XH1627J
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency-Las Vegas, NV
Office of Research and Development
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89114
13. TYPE OF REPORT AND PERIOD COVERED
Interim FY-79
14. SPONSORING'AGENCY CODE
EPA/600/07
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Remote air monitoring using 0.45-micrometer Millipore® filters at eight remote
sites in the Great' Smoky Mountains National Park has shown that lead participates are
contributing to the contamination of this designated biosphere, reserve. Analytical
results of these filters by atomic absorption spectrophotometry, x-ray fluorescence,
and scanning electron microscopy showed that lead air concentrations varied from a higl
of 141.0 ng/m3 to a low of 18.9 ng/m3. / ;
The lead particles were primarily spherical in shape, measuring less, than one
micrometer in diameter. The chemical composition of these submicrometersized particle:
was predominately lead-associated with small amounts of sulfur. The lead particulates
that were greater than 1.0 micrometer in diameter were not spherical in shape and
contained other elements such as iron, calcium, magnesium, and silicon.
The spherical shape of the lead particulates indicates that the moieties were
formed by high temperature processes, such as by internal combustion engines. Also,
the small particulate size may indicate long range transport and subsequent deposition
from urban and/or industrialized areas.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Environmental biology
Site survey
Pollution
Chemistry
Biosphere reserves
Great Smoky Mountains
National Park
06F
08G
08H
07B
07C
07D
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report}
UNCLASSIFIED
21. NO. OF PAGES
16
20. SECURITY CLASS (Thispage}
UNCLASSIFIED
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EPA Form 2220-1 (9-73)
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