&EPA
United Sates
EirvirofimnU Protection
Agency
Survey of New Findings in Scientific
Literature Related to Atmospheric Deposition
to the Great Waters:
Polychlorinated Biphenyls (PCB)
-------
EPA-452/R-07-012
December 2007
Survey of New Findings in Scientific Literature
Related to Atmospheric Deposition to the Great Waters:
Polychlorinated Biphenyls
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Health and Environmental Impacts Division
Climate, International and Multimedia Group
Research Triangle Park, North Carolina
-------
Cover Photograph Credits:
Photo by Pat MacNeill, New York Sea Grant
Extension
Courtesy of U.S. EPA Great Lakes National
Program Office
Photo by Eric Vance, U.S. EPA
Photo by Don Simonelli (courtesy
Michigan Travel Bureau)
Courtesy of U.S. EPA Great Lakes
National Program Office
National Park Service
Courtesy of U.S. EPA Great Lakes
National Program Office
Photo by S.C. Delaney, U.S. EPA
-------
Survey of New Findings in Scientific Literature
Related to Atmospheric Deposition to the Great Waters:
Polychlorinated Biphenyls
1.0 Introduction and Highlights
Atmospheric deposition of pollutants,
including polychlorinated biphenyls
(PCB), has been recognized as a
significant contributor in many
locations to water quality problems,
including toxic contamination offish
and bioaccumulation in wildlife and
humans. The U.S. Environmental
Protection Agency (U.S. EPA) has
been directed by the Clean Air Act to
consider the contribution of
atmospheric deposition to pollution in
the "Great Waters," which comprise
the Great Lakes, Lake Champlain,
Chesapeake Bay, and many of the
estuaries1 of the coastal United States.
PCB are included in the group of
pollutants of concern for the Great
Waters. Background information on
the sources, deposition, and
environmental concentrations of the
pollutants of concern is summarized in
detail in a series of reports, the most
recent of which is "Deposition of Air
Pollutants to the Great Waters Third
Report to Congress" (U.S. EPA 2000),
hereafter referred to as the "Third
Report to Congress."
U.S. EPA is no longer required to
submit reports to Congress on
deposition of air pollutants to the
Great Waters. However, much new
HIGHLIGHTS
Polychlorinated Biphenyls
> Environmental Progress. Decreases in PCB bioconcentration in
fish and fish-eating birds, and increased populations of these
birds in the Great Lakes and southern New Jersey indicate
improvements in ecosystem health. Nationally, PCB
concentrations in mollusks are also showing a decreasing trend,
although many individual locations show no trends. PCB
contamination continues to be a concern to human health in the
Great Lakes, Lake Champlain, northeast coast of the U.S.,
Chesapeake Bay, and some areas of the Pacific coast, including
San Francisco Bay and Puget Sound, as evidenced by fish
consumption advisories in effect in 2004.
^ Temporal and Spatial Trends. In the Great Lakes, PCB
concentrations in sediment, surface water and ambient air have
been declining since the 1970s, although the rate of decline
appears to be leveling off. In general, urban and industrial sites
exhibit higher PCB concentrations than suburban sites, which
show higher concentrations than rural sites. Across many of the
Great Waters, net fluxes of PCB are in the direction of
volatilization from the surface water to the surrounding
atmosphere, making these waterbodies sources of PCB to the
atmosphere.
> Sources. Volatilization from, and combustion of, materials
containing PCB result in emissions. The 2002 National Emission
Inventory cites open burning of residential household waste as a
major contributor nationally. In Chicago, sources include
transformer storage yards, municipal sludge drying beds, and
landfills, among others. Several geographically based studies
looked at a variety of inputs to the waterbodies, including
emission sources, rivers and suspended sediment, discharges, and
global sources. Areas included the mid-Atlantic area, Gulf Coast,
and San Francisco Bay, as well as the Great Lakes.
1 The estuaries that are part of the Great Waters are those that are part of the National Estuary Program (NEP)
administered by EPA or the National Estuarine Research Reserves (NERR) Program administered by the National
Oceanic and Atmospheric Administration (NOAA).
2 The Great Waters pollutants of concern include PCB, mercury, cadmium and lead (and their compounds), several
banned or restricted pesticides, polycyclic organic matter, nitrogen compounds, tetrachlorodibenzo-p-dioxin, and
tetrachlorodibenzofuran. More specific information is at http://www.epa.gov/oar/oaqps/gr8water.
-------
information related to environmental concentrations, deposition trends and sources of PCB in the
Great Waters has been published since the Third Report to Congress, and is compiled here. The
recent research also is compared to findings described in the Third Report to Congress.
References are provided at the end of
this summary.
Definition of Common Terms
Direct deposition: The deposition of air pollution directly
into a body of water (e.g., a large body of water like an
estuary or large lake). The amount of pollution reaching the
water in this way is called the direct load from atmospheric
deposition.
Indirect deposition: The deposition of air pollution to the
rest of the watershed. Once pollutants are deposited in the
watershed, some portion is transported through runoff,
rivers, streams, and groundwater to the waterbody of
concern. The portion that reaches the waterbody by passing
through the watershed is called the indirect load from
atmospheric deposition.
Wet deposition: Pollutants deposited in rain, snow, clouds,
or fog. Acid rain, which has been recognized as a problem
in Europe, eastern Canada, Asia, and areas of the United
States, is an example of wet deposition of sulfur and
nitrogen compounds.
Dry deposition: Pollutants deposited during periods of no
precipitation. This is a complicated process that happens in
different ways depending on the size and chemical nature
of the particle or gas being deposited and the "stickiness"
of the surface. Dry deposition of particles can be thought of
as similar to dust collecting on a table.
Source: U.S. EPA 2001
The recent scientific research
highlights the declining trend in PCB
concentrations and the associated
ecosystem health improvement in the
Great Waters. At the same time, the
research also points to continuing
concerns due to PCB contamination.
2.0 Background
PCB are mixtures of similar synthetic
organic compounds, known as
congeners, that were used widely in
electrical, heat transfer, and hydraulic
equipment; as plasticizers in paints,
plastics and rubber products; in
pigments, dyes and carbonless copy
paper and many other applications.
Manufacture of PCB in the U.S.
ceased in 1977; however, PCB are still
being emitted into the atmosphere via
vaporization from, and open burning
of, products containing PCB.
Additionally, PCB have persisted and
bioaccumulated in the environment as
they are transferred continuously
between air, water, and soil by natural
chemical and physical processes such as weathering, runoff, precipitation, atmospheric
deposition, and advection (Sun et al. 2006). Figure 1 represents a general schematic of the release,
transport, and deposition process for pollutants. While PCB are not emitted from natural or
mobile sources or transformed in the environment, the transport from the atmosphere to
deposition is consistent with Figure 1.
-------
Figure 1. Atmospheric Release, Transport, and Deposition Processes
Source: U.S. EPA 2000
PCB have been shown to cause cancer and a number of serious non-cancer health effects in
animals, including effects on the immune system, reproductive system, nervous system, and
endocrine system. Studies in humans provide supportive evidence for the potential
carcinogenicity and non-carcinogenic effects of PCB (U.S. EPA 1998). Of the various PCB
congeners, several are considered to be similar to dioxin because of their structure and toxicity.
The research results summarized in this report did not distinguish between these dioxin-like PCB
congeners and other congeners. The scientific results described in this survey report typically are
the sum of a subset of PCB congeners; the congeners included in the subset varied among
researchers and can be found in the original references.
3.0 Improvements in Ecosystem Health
Several examples of improved ecosystem health - as reflected in biomarkers - are reported in the
Third Report to Congress. Newly published information is consistent with those findings.
3.1 Great Lakes
3.1.1 Fish
Concentrations of PCB in fish generally have been declining in the Great Lakes since monitoring
began in the 1970s and 1980s. Recent analytical results indicate that on average, total PCB
concentrations in whole Great Lakes top predator fish have declined five percent annually
between 1990 and 2003. This decline has been due largely to various remedial, mitigative, and
pollution prevention efforts, such as the remediation of contaminated sediments and the reduction
of PCB loadings to the Great Lakes (U.S. EPA 2007a, EC and U.S. EPA 2005).
-------
Figure 2 shows these trends for each of the lakes. In Lake Michigan, PCB concentrations in lake
trout have declined consistently over the last two decades. PCB concentrations in lake trout of
Lake Superior fluctuated through the early 1980s, with greater stabilization after that period. A
slight increase was observed in 2000; however, this increase may have resulted from a change in
collection sites, or the fact that the sample population was consuming more contaminated prey
than the previous sample population collected from that site in 1998. In Lake Huron, an overall
decline in PCB concentrations was observed with some periodic increases seen through 2000. As
noted in Figure 2, walleye are collected in Lake Erie as the top predator fish instead of lake trout
because they are more representative of conditions in that lake. PCB concentrations in Lake Erie
increased in the late 1980s through the early 1990s, after which PCB concentrations suddenly
declined. The period of increase corresponds with the introduction of zebra mussels into Lake
Erie. Zebra mussels remove PCB contamination from open water and deposit it in the sediment
making it available to bottom feeding fish. Consequently, higher concentrations are observed in
walleye since they prey on some bottom feeding fish. Finally, in Lake Ontario, PCB
concentrations have declined through 2000 with little observed fluctuation since the late 1990s
(EC and U.S. EPA 2005).
Figure 2. Decline of PCB Fish Contamination in Great Lakes Top Predator Whole Fish"
12
10
C O)
II
o +-
o I
00 5
o £>
Q. O)
(C *""
Superior
Michigan
Huron
*Erie
© Ontario
Source: U.S. EPA 2006
a Data collected for lake trout and reported for sites sampled in even years (the collection site locations
are in different parts of each lake during odd and even years). Note that annual sampling was done at
these sites from 1978 - 1982. Walleye collected in Lake Erie instead of lake trout due to the limited
number of lake trout and the difficulty in collecting them.
-------
Despite the observed trends discussed above, concentrations in Great Lakes fish are still high
enough to be of concern for consumption by wildlife and humans. The Great Lakes Water Quality
Agreement includes a threshold concentration of total PCB in fish tissues (whole fish, calculated
on a wet weight basis) of no more than 0.1 micrograms per gram (|ig/g) or parts per million (ppm)
for the protection of birds and animals which consume fish (U.S. and Canada, 1987). The U.S.
EPA has established a protection value for fish-consuming wildlife and birds at 0.16 ppm in fish
tissue (U.S. EPA 2005a). Figures 2 and 3 demonstrate that PCB concentrations in all of the Great
Lakes for top predator fish exceed these values. Furthermore, PCB levels in Great Lakes fish are
high enough to warrant fish consumption advisories for humans for all five of the Great Lakes;
these are discussed later in this section.
Figure 3. PCB Fish Contamination in Great Lakes Top Predator Whole Fish in 2002
1A
.«!
C
O -10
._ \.£.
(0 ~+j~
£ o) 1-°
a) '53
LJ 2i no
C £ °'8
O +-
OQ) n c
> 0.6
m
O ^ n A
OL B) °'4
C ~ 02
-------
In bald eagles, the Third Report to Congress included a study showing a significant reduction in
PCB concentrations in addled eggs between 1969 and 1993 near Lake Superior. In more recent
studies of bald eagles nesting on the shores of the Great Lakes, PCB concentrations in eggs, blood
and feathers are either decreasing or stable (EC and U.S. EPA 2005). At nests within eight
kilometers of Lake Michigan, PCB concentrations in addled eggs showed no temporal trend over
the period 1986-2000. The overall mean PCB concentration in these eggs was 33.8 |ig/g wet
weight, which is near a concentration associated with reproductive failure (33 |ig/g wet weight) in
an earlier study of bald eagles. A caveat related to this threshold, however, is that there is a strong
correlation between levels of dichlorodiphenyl-dichloroethene (DDE) and PCB in eagle eggs. As
a result, it is difficult to separate the effects of PCB from DDE (Dykstra et al. 2005).
The number of active bald eagle territories in the Great Lakes basin has risen substantially since
the 1970s, when there were practically no successful bald eagle nests along the shores of the
Great Lakes. For example, over the time period between 1997 and 2001, there were on average
about 80 occupied territories near Lake Michigan, and about 190 near Lake Erie. Furthermore,
over this same period, the average number of young fledged per territory per year was close to
one (EC and U.S. EPA 2005). This number of young fledged is indicative of a healthy expanding
population (Dykstra et al. 2005). Yet there are several gaps in the pattern of reproductive
recovery, including reaches of shoreline where the population has not recovered (EC and U.S.
EPA 2005).
3.1.3 Great Lakes Food Web
Morrison et al. (2002) found that differences in concentrations of PCB measured in biota in Lakes
Erie and Ontario were chemical-, species-, and food web-specific. The effects of varying PCB
concentrations in water and sediment on several aquatic biota were modeled and field-verified.
This study suggests that PCB transfer between water and air occurs more quickly than between
water and sediment. This, combined with reductions in deposition of PCB to surface waters over
time in Lake Ontario and eastern Lake Erie, leads to lower PCB concentrations in the water
column, while PCB still remain in sediment in these areas. Therefore, aquatic biota in Lake
Ontario and eastern Lake Erie tend to accumulate less of their PCB body burden from surface
water and more from bottom sediments. As bottom sediments become the predominant source of
PCB to aquatic biota, the concentrations of PCB in aquatic biota are expected to approach
chemical equilibrium with the sediment. This was observed in PCB concentrations in Lake
Ontario lake trout, which are declining more slowly in recent years than previously (Huestis et al.
1996). However, in the western basin of Lake Erie, PCB continue to be input from the Detroit
River and aquatic biota continue to derive a large proportion of their PCB body burden from
suspended PCB in water. Therefore, remediation of contaminated bottom sediments may greatly
reduce contaminant levels in aquatic biota in ecosystems similar to Lake Ontario and the eastern
basin of Lake Erie. On the other hand, a two-pronged remediation approach focused on both
reducing inputs of PCB and decontaminating bottom sediment would be needed in ecosystems
similar to the western basin of Lake Erie (Morrison et al. 2002).
Stapleton et al. (2001) also studied the pathways for PCB inputs to the foodweb in Lake
Michigan. With a slowing of the decline of PCB concentrations in Lake Michigan lake trout in the
mid-1980s, the researchers wanted to understand whether contaminated sediment or atmospheric
-------
inputs were the primary sources of PCB in the food web. This study was done by analyzing
samples of sediment, settling organic matter, suspended paniculate matter (seston) and biota in
various levels of the food web for PCB and stable isotopes of nitrogen and carbon. Stapleton et al.
(2001) concluded that sediments were not the source of PCB to the food chain and that PCB body
burdens are affected by contaminant levels in both seston and settling particles in the water
column. Algal material and seston derive PCB from atmospheric inputs. Furthermore, sediments
are frequently resuspended in Lake Michigan due to storms and other events, which increase the
residence time of particles in the water column. This study, therefore, suggests that response times
for changes in PCB body burden in lake trout is governed by the air-water exchange, residence
time of settling particles, mass flux of particles in the water column, and partitioning of PCB
between the dissolved phase and seston (Stapleton et al. 2001).
3.2 Other Geographic Areas
In southern New Jersey, contamination in osprey eggs and prey fish was studied in 1989 and a
decade later in 1998. Concentrations of PCB in eggs showed about a 60 percent decline from
1989 levels as compared to 1998 levels, while concentrations in prey fish showed about a
35 percent decrease from 1989 levels. The 1998 concentrations of PCB were found to be below
levels considered toxic to egg development, which was exemplified in improved osprey nest
success in the Delaware Bay study area and a 200 percent increase in osprey nesting populations
in the mid-Atlantic coast and Maurice River study areas (Clark et al. 2001).
In coastal waters across the U.S., the National Oceanic and Atmospheric Administration (NOAA)
National Status and Trends Mussel Watch Program has monitored concentrations of trace
chemicals in mussels and oysters since 1986. The sites were selected to be representative of large
areas, rather than smaller-scale areas that are expected to be influenced directly by a particular
source of contaminants. Because mollusks concentrate chemicals from the surrounding waters in
their tissues, they provide an integrated measurement of contaminant trends, rather than a single
point in time (O'Connor 2002). The Mussel Watch Project samples more than 220 sites regularly
(U.S. EPA 2005a). A national-scale analysis of the median PCB concentrations in mollusks from
1986 to 2002 showed a statistically significant decreasing trend (U.S. EPA 2005a).
For 206 individual Mussel Watch sites, 171 sites showed no trend, 30 sites showed a decreasing
trend, and five sites showed an increasing trend for total PCB in mollusk tissue between 1986 and
1999. Specific to sites located in the National Estuarine Research Reserves (NERR), PCB levels
were increasing at one NERR; other sites showed no trend (Lauenstein and Cantillo 2002). A
spatial analysis done by O'Connor (2002) found a correlation between high concentrations of
total PCB and sites in close proximity of urban areas, which is not surprising since PCB are
synthetic chemicals. Many of these high concentration areas are in the northeastern U.S.
Concentrations at some of the urban areas are in a range that possibly may have detrimental
effects to the mollusks by causing alterations in lysosomes of digestive cells (O'Connor 2002). In
one instance, a site exceeded the levels of concern for human consumption of mussels and oysters
set by the Food and Drug Administration (FDA); this was the Angelica Rock site in Buzzards
Bay, Massachusetts in 1989 (O'Connor 2002). The U.S. EPA has more stringent human
consumption guidelines for PCB than FDA. Based on the U.S. EPA's guidelines, there were 47
exceedances for the 222 sites sampled in 2001 and 2002 (U.S. EPA 2005a).
-------
3.3 Fish Consumption Advisories
The contamination offish due to PCB continues to be of concern for human consumption in many
of the Great Waters. Fish consumption advisories can vary in breadth of coverage by population,
fish species, chemical contaminant, and waterbody type, among others. As of 2004, all of the
Great Lakes and Lake Champlain had active fish consumption advisories for them due to PCB
contamination. All the states in the northeastern U.S. had statewide coastal advisories related to
PCB. The Chesapeake Bay and its tributaries also had active advisories. On the west coast of the
U.S., there were advisories for fish and shellfish consumption in San Francisco Bay and Puget
Sound. While advisories to limit fish consumption were rescinded in the Columbia River in
Oregon, there continued to be guidelines to not consume fatty parts of the fish tissue due to PCB
contamination (U.S. EPA 2005b).
Fish Consumption Advisories
U.S. states, territories and Native American tribes are responsible for protecting their residents
from possible health effects of eating fish caught in their boundaries. Fish consumption advisories
are their primary means of limiting human exposure when fish taken from a particular waterbody
contain levels of pollutants that exceed recommended intake levels.
These advisories are issued in several forms - from a comprehensive consumption guide to a
listing of state waterbodies and their associated consumption advice. They can be issued to either
the general population or subpopulations potentially at greater risk (e.g., children, pregnant or
nursing women) to restrict or avoid consumption of specific species of fish and other wildlife
caught locally from specific waters or waterbody types (U.S.EPA 2003b, 2005b). All advisories
are publicly available through the EPA "Fish Advisories" website
(http://www.cpa.gov/watcrscicncc/fish/).
4.0 Temporal and Spatial Trends in PCB Concentrations in Environmental Media
4.1 Temporal Trends in Environmental Media
In general, PCB concentrations in the Great Lakes (Marvin et al. 2002, Marvin et al. 2003,
Morrison et al. 2002, Offenberg and Baker 2000) and Great Lakes atmosphere (Buehler et al.
2002, Sun et al. 2006) are continuing on a downward trend, although the rate of decline in the
Great Lakes may have leveled off in recent years. Marvin et al. (2002) found a three-fold decline
for PCB sediment concentrations between 1971 and 1997 in Lake Erie and a six-fold decline for
PCB sediment concentrations between 1981 and 1998 in Lake Ontario. Similarly, Offenberg and
Baker (2000) reported that the concentration of total PCB in Lake Michigan surface waters has
declined ten-fold between 1980 and 1994. However, while the 1994 average concentration was
clearly lower than concentrations measured in 1991 and 1992, it was similar to the average
concentration measured in spring 1993. In regards to the declining levels observed in the Great
Lakes atmosphere, Buehler et al. (2002) found that atmospheric PCB concentrations decreased
-------
Figure 4. The Great Lakes
with a half-life of 10 years at the Sleeping Bear Dunes and six years at the Eagle Harbor
Integrated Atmospheric Deposition Network (IADN) stations. In Chicago, Sun et al. (2006) found
significant decreasing trends in both precipitation and the atmosphere based on the period 1996 -
2003, with half-lives of about seven years.
The IADN was established in the Great Lakes area to regularly measure select pollutants in air
and precipitation for atmospheric deposition (EC and U.S. EPA 2002). The IADN collects gas,
particle, and precipitation phase samples at each of its master stations and some of its satellite
sites. Master stations are located on Lakes Erie (Sturgeon Point), Michigan (Sleeping Bear
Dunes), Superior (Eagle Harbor), Huron (Burnt Island), and Ontario (Point Petre), while satellite
stations are located in Chicago and Cleveland and
various locations throughout Canada (see Figure 4 for
a map of the Great Lakes). The master stations are
situated in rural locations to obtain representative
regional values, while the Chicago and Cleveland
stations provide useful information about levels of
toxic substances in urban air and precipitation.
Volatilization from the Great Lakes is estimated
using water concentrations from other monitoring or
research projects for some compounds (EC and U.S.
EPA 2004). As a result of the various sources of data,
there exists the potential for inconsistencies in the
data between years and lakes.
The United States - Canadian IADN Scientific Steering Committee (EC and U.S. EPA 2002)
combined IADN gas-phase PCB air monitoring data with other available historic data back to
1977 to analyze changes in atmospheric concentrations since the ban of PCB. The results indicate
an overall decreasing trend (by a factor of seven to 10) in gas-phase PCB air concentrations over
Lakes Superior and Michigan from the late 1970s to the mid-1990s, after which gas-phase PCB
concentrations start to level off.
The precipitation data from IADN stations were analyzed by Simcik et al. (2000) to determine if
wet deposition of semivolatile organic compounds, including PCB, decreased at the same rate as
concentration reductions observed in fish, water and air for data available from 1991 to 1997. The
data indicated similar concentration half-lives in Great Lakes precipitation, air, water, and biota,
suggesting that most of these contaminants are at long-term equilibrium among all environmental
compartments (Simcik et al. 2000). Recent IADN data show PCB concentrations in precipitation
are very low and approaching blank concentrations, most notably at the master stations of Eagle
Harbor and Sleeping Bear Dunes on Lake Superior and Lake Michigan (EC and U.S. EPA 2004).
QitEaHw
Erf*
-------
KEY TERMS
An environmental concentration is the amount (i.e., mass) of a substance within a certain volume or
mass of a given medium. Concentrations are reported in different units, depending on the type of
medium. For example, ambient air concentrations may be reported in units of nanograms per cubic
meter (ng/m3), while concentrations in fish are expressed as parts per million (ppm) - or the milligrams
of PCB per kilogram offish tissue or muscle.
Mass Flux is the rate of mass flow or transfer of a chemical across a unit area. In this report, for
example, flux is reported between surface water and air. It is the rate of diffusion or transport of PCB
across the surface or interface (e.g., nanograms per square meter per day or ng/m2/day). Several fluxes
discussed in this report are:
Wet deposition flux, which is the rate of transfer of a chemical from the atmosphere to the surface
of the earth based on the intensity and frequency of precipitation.
Dry deposition flux, which is the rate of transfer of a chemical from the atmosphere to the surface
of the earth by diffusion and the gravitational settling of contaminated atmospheric particles.
Net gas exchange flux, which is dependent on gas absorption (from the air) and volatilization (from
water to the air).
Net flux, which is the sum of wet deposition, dry deposition and net gas exchange.
4.2 Spatial Trends in Environmental Media
Several new studies evaluated the spatial trends in PCB concentrations for various environmental
media, often with a focus on comparisons between urban, suburban, and rural locations. Spatial
trends consistent with those reported in the Third Report to Congress also have been reported in
the new studies. That is, waterbodies and/or the air in urban and industrial settings show higher
concentrations than those in suburban settings, which show higher concentrations than those in
remote locations (Brunciak et al. 2001, Chiarenzelli et al. 2000, Totten et al. 2003, Van Ry et al.
2002, Buehler and Kites 2002, Liu 2003, Reinfelder et al. 2004, Totten et al. 2004). Table 1
summarizes the relative concentrations of PCB in different media at various geographic locations
based on comparisons made within the studies.
A number of researchers demonstrated how passive air samplers could be used to examine the
urban-to-rural changes in PCB concentration. Passive air samplers were deployed for three 4-
month integration periods from June 2000 to July 2001 from Toronto urban sites to a rural site
about 75 kilometers to the north. Urban concentrations were about five to 10 times rural
concentrations. The researchers also found that the PCB mixture was different between urban and
rural sites. The higher-chlorinated PCB, typically associated with the particle phase, were found
in greater concentration at the urban sites. At the rural sites, the PCB mixture had more PCB
congeners with lower chlorination, typically associated with the gas phase. The researchers
believe that this is due to higher particle concentration and deposition fluxes in urban areas
(Harner et al. 2004, Motel ay-Mas sei et al. 2005).
10
-------
Table 1. Spatial Comparisons of PCB Concentrations in Different Mediums
Medium
Atmosphere
Precipitation
Surface Water
Sediment
Biota
Concentration Comparison3
Chicago > coastal New Jersey sites > Great Lakesb
Chicago > Galveston Bay > Corpus Christi Bay0 >
Chesapeake Bayd
Akwesasne Mohawk Nation lands (New York, along the
St. Lawrence River) > Great Lakes
Downwind of Lake Ontario > Great Lakes
Northern San Francisco Bay > rural Chesapeake Bay >
Great Lakes
Camden > Jersey City > rest of New Jersey
Chicago ~ urban-industrial New Jersey sites
Great Lakes rain concentrations ~ snowpack
concentrations in Minnesota within 50 km of Lake
Superior
Chesapeake Bay ~ urban-impacted suburban New Jersey
sites
Lake Ontario > Lake Erie6
Green Bay (in northwestern Lake Michigan) > southern
Lake Michigan
Lake Ontario > Lake Erie
Lake Ontario > Lake Winnipeg ~ Lake Superior = Lake
Michigan
Lake Ontario > western Lake Erie > eastern Lake Erie
Source
Brunciaketal. 2001
Park etal. 2001, Park et
al. 2002
Chiarenzelli et al. 2000
Chiarenzelli et al. 2001
Tsai et al. 2002
Reinfelder et al. 2004,
Totten et al. 2004
Van Ry et al. 2002,
Sun et al. 2006
Franz and Eisenreich
2000
Van Ry et al. 2002
Morrison et al. 2002
Totten et al. 2003
Morrison et al. 2002,
Marvin et al 2002
Rawn et al. 2000
Morrison et al. 2002
Comparisons are designated based on subjective author determination in the source cited, and are denoted using
">" to indicate greater than and "~" as approximately equivalent.
Great Lakes refers to the IADN master stations located on Lakes Erie (Sturgeon Point), Michigan (Sleeping Bear
Dunes), Superior (Eagle Harbor), Huron (Burnt Island), and Ontario (Point Petre).
Galveston Bay atmospheric PCB concentrations are approximately four times greater than atmospheric
concentrations at Corpus Christi Bay.
Corpus Christi Bay atmospheric PCB concentrations are slightly greater than atmospheric concentrations at
Chesapeake Bay.
Water concentrations in Lake Ontario are 1.3 to 2.3 times greater than water concentrations in the western basin of
Lake Erie, which is influenced by Detroit River industrial inputs, and approximately 1,000 to 6,000 times greater
than water concentrations in Lake Erie's eastern basin, which is more isolated from industrial inputs.
11
-------
Relative to other IADN sites in the Great Lakes region, PCB continue to be found in the largest
amounts at the Chicago IADN sampling site (Buehler and Kites 2002, Sun et al. 2006). Data from
this site have been used to represent the whole Chicago urban area. Basu et al. (2004) conducted a
short-term ambient air monitoring study at a second site closer to downtown Chicago and
compared the results with data from the IADN site, to get an idea of possible differences among
locations. Monitoring of vapor and particle-phase PCB in the ambient air at this second site was
conducted from February to October 2002. The PCB congener patterns were virtually identical
between the two sites. The average PCB concentrations at this second site ranged from
0.7 to 4.6 nanograms per cubic meter (ng/m3). These were about two times higher than the IADN
site over the same period (0.3 to three ng/m3). If PCB loadings to southern Lake Michigan due to
the Chicago area were recalculated using information from this second site, they would increase
by about 13 kilograms/ year (kg/yr). This comparison shows that there can be variations of PCB
concentrations within urban areas. Further research is necessary to better understand these
variations.
Similarly, several new studies found that Chicago continues to be a dominant source of PCB to
southern Lake Michigan (Zhang et al. 1999, Green et al. 2000, Offenberg and Baker 2000,
Offenberg and Baker 2002). Direct deposition of atmospheric PCB from the Chicago area to Lake
Michigan occurs quickly relative to the horizontal mixing of the lake's surface waters. This rapid
deposition is due to air-water gas exchange and wet and dry deposition that occur when winds
carry the urban plume from Chicago over southern Lake Michigan. Green et al. (2000) noted the
variability of the influence of Chicago, depending on temperature and wind direction. Offenberg
and Baker (2000) found that southwesterly winds, and associated storms, that cross over Chicago
towards southern Lake Michigan coincide with a nearly two-fold increase in PCB concentrations
in southern Lake Michigan surface waters. Zhang et al. (1999) estimated that the urban plume
from Chicago affects as much as the entire southern quarter of Lake Michigan, while other
researchers estimated the affected area to be only five percent or less (Offenberg and Baker
2002). However, even with the inputs of PCB from Chicago, the PCB concentrations in surface
waters of southern Lake Michigan are significantly less than those found in Green Bay, located in
northwestern Lake Michigan at the mouth of the Fox River. Green Bay has historically received
inputs from 13 paper mills and five major municipal wastewater treatment plants (Totten et al.
2003).
Several studies have examined Lake Ontario and the surrounding environment and have
compared the results with Lake Erie and its surrounding environment. An ambient air monitoring
study by Chiarenzelli et al. (2001) found PCB concentrations downwind of Lake Ontario, on its
southeastern shore, to have higher PCB concentrations (with averages roughly around one ng/m3)
than a site near Lake Erie, which had concentrations (averaging 0.22 ng/m ) similar to regional
backgrounds as measured by IADN. The samples near the Lake Ontario shore also showed higher
chlorination, which ruled out volatilization from the lake as a primary source of the PCB. The
researchers hypothesized that volatilization from local sources is a major contributor to the air
concentrations. These could be reservoir sources, such as soil, sediment and vegetation from
previous deposition, although further research would be needed to determine the exact source
(Chiarenzelli et al. 2001).
12
-------
Marvin et al. (2002) and Morrison et al. (2002) found that sediment concentrations in Lake
Ontario were greater than those in Lake Erie. Similarly, PCB concentrations in Lake Ontario
surface waters were 1.3 to 2.3 times greater than those in the western basin of Lake Erie (which is
heavily influenced by Detroit River industrial inputs), and 1,000 to 6,000 times greater than those
in the more isolated eastern basin of Lake Erie (Morrison et al. 2002). This trend represents a shift
from the 1970s, when concentrations were greater in Lake Erie's eastern basin relative to its
western basin. This reversal is likely due to the remediation of several hazardous waste sites
located along the eastern shore of Lake Erie, which suggests the success of the Superfund
program (Marvin et al. 2002). Following the spatial trend of PCB found in the water column,
Morrison et al. (2002) reported that PCB concentrations in biota are greatest in Lake Ontario,
followed by western Lake Erie, and then eastern Lake Erie.
One study reported an exception to the land use spatial trend for PCB concentrations. Near Lake
Superior, researchers found no clear spatial variation among PCB concentrations in snowpacks
sampled in urban and suburban areas near Minneapolis/St. Paul, and those in more remote areas,
including Eagle Harbor (on Lake Superior) and northern Minnesota. This observation suggests a
well-mixed atmospheric source signal in the region (Franz and Eisenreich 2000).
5.0 Air/Water Fluxes
Figure 5 shows the change in annual net gas exchange flux from 1992 through 2000 for the Great
Lakes based on IADN monitoring data. Net gas exchange is the difference between gas
absorption from the air to the water and volatilization from water to the air (see key terms text box
in Section 4). These results indicate that the surface waters of the Great Lakes have been
volatilizing PCB into the atmosphere for several years because the rate of volatilization generally
decreases with time and approaches equilibrium between air and water (Buehler and Kites 2002,
EC and U.S. EPA 2000, EC and U.S. EPA 2002, EC and U.S. EPA 2004). Lake Erie, which may
be influenced by PCB sources in New York State, typically has the largest gas exchanges and
shows an exceptional trend where the rate of volatilization may be increasing (EC and U.S. EPA
2000, EC and U.S. EPA 2004).
13
-------
Figure 5. Net Gas Exchange Flux for the Great Lakes
(from Surface Water to Air)
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
ake Ontario
1992 1993
1994
1995
1996
1997
1998 1999
2000
Source: EC and U.S. EPA 2004
The net gas exchange of PCB from the Great Lakes overwhelms the inputs via wet and dry
deposition, making the Great Lakes a source of PCB to the atmosphere. Dry particle
concentration measurements in IADN ceased after 1995 due to low reported levels. Wet
deposition fluxes show no consistent change over time. These fluxes are similar among lakes for
which there are recent data (Erie, Superior and Michigan); annual average wet deposition fluxes
in these lakes have generally ranged between 1 and 4 ng/m2/day over the period from 1992 to
2000 (EC and U.S. EPA 2004). Lake Huron wet deposition fluxes decreased until 1994 when the
last PCB precipitation measurements were taken there (EC and U.S. EPA 2000).
Researchers recently re-evaluated gaseous fluxes of PCBs between water and air from two
locations on Lake Michigan: Green Bay (located in northwestern Lake Michigan), and southern
Lake Michigan (near the urban/industrial areas of Chicago, Illinois and Gary, Indiana). They
found that net volatilization fluxes are more important for the removal of PCB from these waters
than previously recognized. Due to historically elevated concentrations in the waters of Green
Bay, the net volatilization flux from Green Bay is greater than the flux reported for Lake
Michigan and the other Great Lakes. Totten et al. (2003) updated previous calculations with
improved Henry's law constant3 estimates for PCB (Bamford et al. 2000) and new relationships
for estimating mass-transfer rates across the air-water interface. They also suggested that the
magnitude of the air-water gaseous exchange flux is a stronger function of daily meteorological
conditions than previously recognized.
3 Henry's law states that the amount of a gas that will be absorbed by water increases as the gas pressure increases.
Henry's law constant is frequently used to define the distribution of a chemical across the air/water interface.
14
-------
The resulting new calculations indicate that the net PCB volatilization flux from Green Bay is two
to 20 times higher than had been estimated previously. In addition, the new evaluations indicate
that net volatilization was the dominant loss process in both summer and winter from southern
Lake Michigan during the summer of 1994 and January 1995. These results contrast with
previous studies that calculated absorption of PCB by surface waters in the summer 1994, when
air concentrations above southern Lake Michigan were elevated because of westerly winds
blowing from the Chicago, Illinois, and Gary, Indiana, urban/industrial areas (Offenberg and
Baker 2000, Zhang et al. 1999). However, due to the influence of local inputs from Chicago, wet
deposition and dry particle deposition to southern Lake Michigan continues to outweigh
volatilization. Volatilization and sediment burial are roughly equal in importance in removing
PCB from southern Lake Michigan waters (Totten et al. 2003).
Scavenging as a Removal Mechanism
Scavenging mechanisms for removing PCB from the atmosphere include gas exchange with
surface waters, dry deposition to surface waters, and precipitation scavenging, also known as
washout. Gaseous PCB can dissolve into water both within clouds and into falling
precipitation. Similarly, PCB particulates can be melded into falling precipitation. In either
form (gaseous or particle), PCB can be essentially washed into another medium, e.g., a lake,
from the atmosphere. Offenberg and Baker (2002) studied this phenomenon around southern
Lake Michigan.
The study was conducted to measure the effectiveness and relative importance of precipitation
scavenging mechanisms during a variety of storm events, with measuring stations located at
urban locations, over water, and following a downwind transect. Offenberg and Baker (2002)
concluded that washout mechanisms are largely variable between storm events, and the
relative importance of each removal mechanism generally does not vary greatly along a
storm's path. Therefore, the storm type (i.e., meteorological and precipitation characteristics)
controls precipitation scavenging, where particle scavenging, rather than gas scavenging,
dominates washout mechanisms for PCB in a wide range of precipitation events. Van Ry et al.
(2002) further confirm that, on average, 97 percent of total atmospheric washout is from
particle scavenging at a variety of sites in the Mid-Atlantic States.
15
-------
Table 2 shows the direction and magnitude of several reported net gas exchanges at the air-water
interface for select Great Waters.
Table 2. PCB Net Gas Exchange from Select Great Waters
Waterbody
NY Harbor
Green Bay, WI
Raritan Bay, NJ
Galveston Bay, TX
Corpus Christ! Bay, TX
Chesapeake Bay
Lake Erie (Sturgeon Point)
Lake Ontario (Point Petre)
Lake Huron (Burnt Island)
Lake Michigan (Sleeping Bear
Dunes)
Lake Superior (Eagle Harbor)
Northern San Francisco Estuary
Year and Period
1998 July
1989 June through October
average
1998 July
1995-96 annual
1998-99 annual
1992 annual
2000 annual
2000 annual
2000 annual
2000 annual
2000 annual
2000 June through November
Net Gas
Exchange
(ng/m2/day)
-2100
-1200
-400
-195
-184
-96
-58
-40
-22
-12
-5
-2.2 to -24
Source
Tottenetal. 2001
Totten et al. 2003
Tottenetal. 2001
Park etal. 2001
Park et al. 2002
Totten et al. 2003a
EC and U.S. EPA
2004
EC and U.S. EPA
2004
EC and U.S. EPA
2004
EC and U.S. EPA
2004
EC and U.S. EPA
2004
Tsai et al. 2002
Note: Negative net gas exchanges indicate loss of concentration in surface water (i.e., volatilization).
a From Nelson et al. 1998
NY Harbor, Green Bay and Raritan Bay, with the highest net volatilization rates, have all been
impacted historically by industrial contamination (Totten et al. 2003). The Great Lakes net
volatilization exchange is less than that for both Corpus Christi Bay and Galveston Bay, Texas,
possibly due to the higher average surface water temperatures in the southern estuaries relative to
the northern lakes (Park et al. 2002).
Wet deposition fluxes reported for Chesapeake Bay, Galveston Bay, Lake Superior, and Green
Bay (Lake Michigan) were all similar (Park et al. 2001). Park et al. (2001) also found the dry
deposition flux at Galveston Bay to be two-fold higher than the rate for Chesapeake Bay. PCB
concentrations in air and rain samples collected at Corpus Christi Bay were four times lower than
those found at Galveston Bay, but net volatilization fluxes were similar at both locations. For
northern San Francisco Estuary, a combined flux of gaseous and particulate dry deposition PCB
showed a net release of PCB from the water to the atmosphere, during a six-month study (June to
16
-------
9
November) in 2000. The monthly fluxes ranged from 0.15 to 23 ng/m /day; the highest
volatilization rates occurred in the summer months. Wet deposition was not included in this study
(Tsai et al. 2002). The studies referenced in Table 2 all note that net gas exchange is the dominant
mode of transfer of PCB between the atmosphere and surface water. Therefore, the net flux is
volatilization of PCB from the waterbody to the atmosphere.
Deposition fluxes were estimated for multiple sites across New Jersey through the New Jersey
Atmospheric Deposition Network (NJADN). The network, which operated roughly between 1998
and 2001, included sites in urban, suburban, coastal and forested areas. The annual deposition
fluxes (not accounting for volatilization) ranged from 20 to 931 ng/m2/day, with the highest
values in the urban areas. For the sites near the Hudson River Estuary, which is adjacent to urban
areas, these fluxes are at least two to 10 times those estimated for the Chesapeake Bay and Lake
Michigan. For low molecular weight PCB (congeners containing two to five chlorines),
volatilization from the Hudson River Estuary exceeds atmospheric deposition (Reinfelder et al.
2004, Totten et al. 2004).
6.0 Emissions and Sources
6.1 Emissions
Numerous new studies reported on the sources of PCB to the environment. As noted earlier, PCB
are no longer manufactured, and their use and handling are regulated under the Toxics Substances
and Control Act (TSCA). Nevertheless, because PCB were widely used at one time, volatilization
from or combustion of materials containing PCB can be sources to the atmosphere. Areas of past
PCB contamination can also be sources. As noted in the previous section, many of the Great
Waters themselves are sources of PCB to the atmosphere. Consequently, estimating PCB
emissions to the atmosphere is challenging and can have a high degree of uncertainty.
The National Emissions Inventory (NET) is a national database of air emissions information with
input from numerous state and local air agencies, from tribes, and from industry. A list of the
source categories that contribute to the 26 tons per year of PCB air emissions estimated for 2002
is provided in Appendix A. Open burning of residential household waste, is the largest contributor
in the 2002 NEI (estimated to be 23 tons per year nationally) (U.S. EPA 2007b). However, this
activity is not likely to represent the largest source of emissions in urban areas. The text box in
this section highlights studies designed to better understand urban sources, specifically in
Chicago.
6.2 Source areas affecting the Great Lakes
The Great Lakes continue to be impacted by atmospheric deposition and industrial point and
nonpoint sources. There are no new PCB sources reported for Lake Erie. The Detroit River
continues to be the dominant contributor of PCB to Lake Erie (approximately 75 percent),
especially in the western basin and near shore areas along the Ohio shoreline (Morrison et al.
2002); the Clinton, Maumee, and Cuyahoga Rivers also contribute to PCB loadings in Lake Erie.
Lake Erie also receives atmospheric inputs of PCB from the urban areas of Toledo, Cleveland,
and Ashtabula, Ohio (Marvin et al. 2002). In contrast to Lakes Superior and Michigan, local
17
-------
contaminant sources (primarily hazardous
waste facilities on the Niagara River) play
a greater role in Lake Ontario PCB
loadings than does atmospheric
deposition (Marvin et al. 2002). Franz and
Eisenreich (2000) reported that falling
snow, rather than dry deposition, is the
dominant source of PCB to snowpacks; if
gaseous PCB are sorbed to snow, it likely
happens during snowfall. These
researchers estimate that 30 to 40 percent
of snowpack meltwater from the Lake
Superior basin enters Lake Superior
during a few weeks in the spring.
Hafner and Kites (2003) examined
potential source regions for PCB
measured at several of the Great Lakes
IADN monitoring sites. Their analysis
used the Potential Source Contribution
Function (PSCF) Model, which is a
probabilistic back-trajectory modeling
technique. Sturgeon Point, on Lake Erie,
is the most eastern of the sites, and
appears to be strongly influenced by the
heavily urban east coast. Sleeping Bear
Dunes, on Lake Michigan, appears to be
influenced by areas to the south and
southwest; there are virtually no
indications of influence from the north.
The greater Chicago area appears to be
the most influential region for Eagle
Harbor, on Lake Superior. In later work,
Hafner and Kites (2005) did further
modeling analysis of the Great Lakes
region. The typical regression model
includes a factor for air temperature at the
site and a factor representing the change
in emission rate as a function of time.
This analysis examined three ways to
incorporate a factor to represent direction
from which the pollutant came: local wind
direction; average backward trajectory of air coming to the site; and a nonparametric air trajectory
based on hypothesized source regions determined by the PSCF model. For PCB, the information
derived from the models was not improved substantially by including a source direction factor.
Hybrid Receptor Models Indicate
Chicago PCB Source Areas
Two new studies using three types of hybrid receptor
models and verified by field samples indicate a large
potential atmospheric PCB source area southwest of
Chicago between Kankakee and Joliet, Illinois, and
two moderate PCB sources to the northwest in the
direction of Madison, Wisconsin, and south of
Chicago in the Lake Calumet neighborhood (Hsu et
al. 2003a, Hsu et al. 2003b). Gary, Indiana, is also a
potential PCB source to the air. The indication of
sources to the south and southwest is consistent with
higher temperatures associated with winds from this
direction causing volatilization of previously
deposited PCB (Hsu et al. 2003b). Specifically, a
large transformer storage yard, municipal sludge
drying beds, and a large landfill in Chicago were
confirmed as contributors of atmospheric PCB. At
the landfill, PCB may escape from either landfill gas
or the wastewater sludge that is used as a cover.
Other potential sources identified include the
Chicago Confined Disposal Facility, which contains
dredged sediment contaminated with PCB, and the
Indiana Harbor and ship canal, which are in a highly
industrial area with steel manufacturing and
petroleum refineries and which contain some of the
most highly contaminated sediments in Lake
Michigan (Hsu et al. 2003b). Lake Michigan is not
an atmospheric source to Chicago (Hsu et al. 2003a).
Modeling results were relatively consistent between
the models; however, no single model provided
information as complete as that obtained by using all
three in conjunction (Hsu et al. 2003a). It should also
be noted that many small sources not identified in
these studies may collectively contribute a larger
amount of PCB to the Chicago air (Hsu et al. 2003b).
In turn, modeling results reported by the United
States - Canada IADN Scientific Steering Committee
(EC and U.S. EPA 2002) cite the urban area of
Chicago and northwestern Indiana as a source of
PCB to Lake Superior.
18
-------
Although the majority of PCB in the Great Lakes atmosphere come from North American
sources, analyses using the Lawrence Berkeley National Laboratory Berkeley-Trent (BETR)
Global model estimates fractions of loadings from other areas of the world. A comparative
analysis of cumulative historical emissions to emissions in 2002 indicates that relative
contributions from global sources other than North America are increasing, as North American
sources decrease. Specifically, Eastern Europe appears to be emerging as a relatively more
important source of PCB deposition in the Great Lakes. However, there is a wide range of
uncertainty associated with this assessment mainly due to uncertainty in emission estimates (U.S.
EPA and EC 2005).
6.3 Source areas affecting other Great Waters
In the coastal New Jersey region, a study by Brunciak et al. (2001) concludes that atmospheric
PCB derive from a dominant source type/area and process(es), possibly water treatment plants. In
addition, volatilization from the Hudson River and surrounding rivers contributes PCB to the
atmosphere. At individual sites, temperature, wind direction and speed, and distance from the
source(s) determine the absolute concentration of PCB. In the Baltimore, Maryland area, a study
conducted within the Chesapeake Bay watershed hypothesized that building materials used prior
to 1980, paints and dielectric fluids used in electrical transformers and capacitors prior to the
early 1970s, and a medical waste incinerator were potential sources of PCB found in films on
exterior window surfaces (Liu et al. 2003). Precipitation readily removes the film, which may
subsequently wash into nearby surface waters and eventually the Chesapeake Bay.
In the Corpus Christi Bay and Galveston Bay regions, as noted in section 5, new studies indicate
that these surface waters are currently acting as sources of PCB to the atmosphere via net
volatilization flux of vapor PCB from the water surface (Park et al. 2002, Park et al. 2001). Wind
speed, wind direction, and air temperature affect local PCB concentrations in air and rain samples
at both bays. Winds deriving from the Gulf of Mexico tend to exhibit a dilution effect on local
atmospheric PCB concentrations, and winds from urban/industrial areas tend to increase local
atmospheric PCB concentrations. Lower wind speeds were correlated with increased PCB
concentrations in air, as were higher air temperatures. At Galveston Bay, concentrations of
dissolved and particulate PCB also showed a weak dilution effect based on the volume of rain
(Park et al. 2001). Regional airports may contribute PCB to Corpus Christi Bay (Park et al. 2002).
In the San Francisco Bay, Johnson et al. (2000) studied the parameters of PCB sorbed to
particulates in the surface waters to better understand the sources of PCB in this area. Sediment
resuspension is suspected to be the dominant source for three out of five PCB analytes studied
because the highest levels were observed in the winter and spring when there was high freshwater
inflow and high total suspended solids. The source of the fourth PCB analyte is suspected to be
due to a restricted release or a spill and the fifth PCB analyte from either the atmosphere (because
similar patterns have been observed in ambient samples of marine and urban air) or sewage
inputs.
19
-------
7.0 Summary and Some Future Directions in Research
Generally, PCB concentrations are declining or reaching steady-state in the environment (air,
water, sediment, biota) surrounding the Great Waters, resulting in observed improvements to
ecosystem health in most cases. Nevertheless, PCB concentrations in biota continue to be of
concern for wildlife and humans, leading to fish consumption advisories in many of the Great
Waters.
The PCB concentration in fish and fish-eating birds in both the Great Lakes and southern New
Jersey are lower than in the 1970s, and populations of these birds in both areas have increased
substantially. Yet, in the Great Lakes, PCB concentrations in top predator fish exceed thresholds
established for fish-consuming birds and wildlife, and there are reaches of shoreline where the
bald eagle population has not recovered.
State and tribal advisories for human consumption offish were in effect in 2004 for all the Great
Lakes, Lake Champlain, coastal waters of the northeastern states, Chesapeake Bay and its
tributaries, San Francisco Bay and Puget Sound. Data from NOAA's Mussel Watch program
indicated that the median concentration in mollusks nationally is decreasing. However, most
individual Mussel Watch sites show no trend, including the majority of sites in NERR locations.
Several new studies evaluated spatial trends in PCB concentrations for various environmental
media. Consistent with findings discussed in the Third Report to Congress, higher concentrations
tended to be found in urban and industrial areas than in remote locations. Recent studies related to
Corpus Christi, Galveston, and San Francisco Bays, New Jersey and the mid-Atlantic region
provided information related to PCB air concentrations and air-water fluxes in Great Waters for
which there previously were no data.
Similar to results identified in the Third Report to Congress, the new studies indicated that in
many Great Waters, volatilization of PCB from the surface water to the air is taking place at a
higher rate on average than PCB are entering the water from the air via wet and dry deposition
and gas absorption, making these waterbodies sources of PCB to the atmosphere. However,
deposition inputs from sources near Chicago outweigh volatilization in southern Lake Michigan.
Emission sources of PCB include volatilization from or combustion of material containing PCB.
The National Emissions Inventory cites open burning of residential household waste as a major
contributor nationally. A study in Chicago found that emission sources there included a
transformer storage yard, municipal sludge drying beds, and a landfill, among others.
Recent studies considered source areas affecting waterbodies in various geographic areas. Inputs
examined included rivers, suspended sediments, discharges, and global sources, in addition to
domestic emission sources.
Several of the articles in the recent literature recommend continued research to improve
knowledge related to PCB trends, and sources, fate, and transport. Investigators' specific
recommendations for some future research are as follows:
20
-------
Research is needed to determine why there are higher airborne PCB concentrations
and chlorination east of Lake Ontario compared to IADN sites throughout the Great
Lakes Basin (Chiarenzelli et al. 2001).
Volatilization from surface water is an important removal process of PCB from
Corpus Christi Bay and Galveston Bay. However, despite technological advances over
the past decade, further reliable estimates of physical-chemical parameters like
Henry's Law constant and mass transfer coefficient, as well as deposition velocity and
loadings from other sources are needed to improve the accuracy of atmospheric
loading estimates for semi-volatile organic contaminants (Park et al. 2002; Park et al.
2001).
Concentrations of PCB in water and sediment naturally change over time; therefore it
is necessary to further research the fate and transport of PCB in the ecosystem so that
effective measures can be taken to reduce the resulting contaminant burdens of aquatic
biota (Morrison et al. 2002).
Although the current IADN is extremely useful, it must continue to grow and adapt to
emerging concerns in the region. Further research is still necessary to pinpoint
potential sources of pollution to the Great Lakes using IADN meteorological and
concentration data, and to develop new urban study sites (Buehler and Kites 2002).
Long-term monitoring (i.e., decades of monitoring) is also necessary to fully
understand how PCB compounds degrade in the environment (Buehler et al. 2002).
Research is needed to address PCB sources in a global setting. In particular, further
research is necessary in order to accurately characterize emissions in the global setting
(U.S. EPA and EC 2005).
21
-------
8.0 References
Bamford, H.A., D.L. Poster, I.E. Baker. 2000. Henry's law constants of polychlorinated biphenyl
congeners and their variation with temperature. J. Eng. Data. 45:1068-1074.
Basu, I, W.D. Hafner, WJ. Mills, R.A. Kites. 2004. Differences in atmospheric persistent
organic pollutant concentrations at two locations in Chicago. J. Great Lakes Res.
30(2):310-315.
Buehler, S.S. and R.A. Kites. 2002. The Great Lakes' Integrated Atmospheric Deposition
Network: The United States and Canada continue an effective partnership that measures
nonpoint source pollution. Environ. Sci. Technol. 354A-359A.
Buehler, S.S., I. Basu, and R.A. Kites. 2002. Gas-phase polychlorinated biphenyl and
hexachlorocyclohexane concentration near the Great Lakes: a historical perspective.
Environ. Sci. Technol. 36: 5051-5056.
Brunciak, P.A., J. Dachs, C.L. Gigliotti, E.D. Nelson, and S.J. Eisenreich. 2001. Atmospheric
polychlorinated biphenyl concentrations and apparent degradation in coastal New Jersey.
Atmos. Environ. 35: 3325-3339.
Chiarenzelli, J., J. Pagano, R. Scrudato, L. Falanga, K. Migdal, A. Hartwell, M. Milligan, T.
Battalagia, T. Holsen, Y. Hsu, and P. Hopke. 2001. Enhanced airborne polychlorinated
biphenyl (PCB) concentrations and chlorination downwind of Lake Ontario. Environ. Sci.
Technol. 3280-3286.
Chiarenzelli, J., B. Bush, A. Casey, E. Barnard, B. Smith, P. O'Keefe, E. Gilligan, and G.
Johnson. 2000. Defining the sources of airborne polychlorinated biphenyls: Evidence for
the influence of microbially dechlorinated congeners from river sediment? Canadian J.
Fisheries Aquatic Sci. 57 (Suppl. 1): 86-94.
Clark, K.E., W. Stansley, and L.J. Niles. 2001. Changes in contaminant levels in New Jersey
osprey eggs and prey, 1989 to 1998. Arch. Environ. Contain. Toxicol. 40: 277-284.
Dykstra, C.R., M.W. Meyer, S. Postupalsky, K.L. Stromborg, O.K. Warnke, and R.G. Eckstein.
2005. Bald eagles of Lake Michigan: Ecology and contaminants. State of Lake Michigan:
Ecology, Health and Management, Editors T. Edsall andM. Munawar, Ecovision World
Monograps Series, Aquatic Ecosystem Health and Management Society. 365-392.
Environment Canada (EC) and U.S. Environmental Protection Agency (U.S. EPA). 2005. State of
the Great Lakes 2005. Environment Canada (Enl61-3/0-2005E) and the United States
Environmental Protection Agency (EPA 905-R-06-001). Accessed online at
http://binational.net/solec/English/SOLEC%202004/Tagged%20PDFs/SOGL%202005%2
OReport/English%20Version/Complete%20Report.pdf on March 16, 2007.
EC and U.S. EPA. 2004. Atmospheric deposition of toxic substances to the Great Lakes: IADN
results through 2000. Environment Canada (En56-156/2000-IE) and the United States
Environmental Protection Agency (EPA 905-R-04-900). Accessed online at
22
-------
September
27, 2006.
2003. State of the Great Lakes 2003. Environment Canada (En40-l 1/35-2003E) and the United
States Environmental Protection Agency (EPA 905-R-03-004). Accessed online at
Report.pdf on September 27, 2006.
EC and U.S. EPA. 2002. Cooperating to Implement the Great Lakes Water Quality Agreement:
Technical Summary of Progress of the Integrated Atmospheric Deposition Network
(IADN) 1997-2002. United States - Canada IADN Scientific Steering Committee. October
2002. Accessed online at
http://www.epa.gOv/glnpo/tnonitoring/air/iadn/I ADN_Tech_Rpt_Final_verC.pdf on
September 27, 2006.
EC and U.S. EPA. 2000. Air Quality Research Branch Toronto (Ontario). Atmospheric deposition
of toxic substances to the Great Lakes: IADN results to 1996, United States. Great Lakes
National Program Office (Canada). Environment Canada (En56-156/2000E-IN) and the
United States Environmental Protection Agency (EPA 905-R-00004). Accessed online at
http;//wwwjgpa^ on September 27,
2006.
Franz, T.P., and SJ. Eisenreich. 2000. Accumulation of polychlorinated biphenyls and polycyclic
aromatic hydrocarbons in the snowpack of Minnesota and Lake Superior. J. Great Lakes
Res. 26(2): 220-234.
Green, M.L., J.V. Depinto, C. Sweet, and K.C. Hormbuckle. 2000. Regional spatial and temporal
interpolation of atmospheric PCB: Interpretation of Lake Michigan mass balance data.
Environ. Sci. Technol. 34: 1833-1841.
Hafner, W.D., and R. Kites. 2005. Effects of wind and air trajectory directions on atmospheric
concentration of persistent organic pollutants near the Great Lakes. Environ. Sci. Technol.
39: 7817-7825.
Hafner, W.D., and R. Kites. 2003. Potential sources of pesticides, PCB, and PAHs to the
atmosphere of the Great Lakes. Environ. Sci. Technol. 37:3764-3773.
Harner, T., M. Shoeib, M. Diamond, G. Stern, and B. Rosenberg. 2004. Using passive air
samplers to assess urban-rural trends for persistent organic pollutants. 1. polychlorinated
biphenyls and organochlorine pesticides. Environ. Sci. Technol. 38: 4474-4483.
Hsu, Y-K., T.M. Holsen, and P.K. Hopke. 2003a. Comparison of hybrid receptor models to locate
PCB sources in Chicago. Atmos. Environ. 37: 545-562.
Hsu, Y-K., T.M. Holsen, and P.K. Hopke. 2003b. Locating and quantifying PCB sources in
Chicago: Receptor modeling and field sampling. Environ. Sci. Technol. 37(4): 681-690.
23
-------
Johnson, G.W., W.M. Jarman, C.E. Bacon, J.A. Davis, R. Ehrlich, and R.W. Risebrough. 2000.
Resolving polychlorinated biphenyl source fingerprints in suspended particulate matter of
San Francisco Bay. Environ. Sci. Technol. 34(4): 552-559.
Lauenstein, G.G. and A.Y. Cantillo. 2002. National Status and Trends Program for Marine
Environmental Quality: Contaminant Trends in US National Estuarine Research Reserves.
National Oceanic and Atmospheric Administration (NOAA) National Ocean Service
(NOS) Technical Memorandum National Centers for Coastal Ocean Science (NCCOS)
156. October 2002. Accessed online at
September 27, 2006.
Liu, Q-T., M.L. Diamond, S.E. Gingrich, J.M. Ondov, P. Maciejczyk, and G.A. Stern. 2003.
Accumulation of metals, trace elements and semi-volatile organic compounds on exterior
window surfaces in Baltimore. Environ. Poll. 122: 51-61.
Marvin, C.H., M.N. Charlton, G.A. Stern, E. Braekevelt, EJ. Reiner, and S. Painter. 2003. Spatial
and temporal trends in sediment contamination in Lake Ontario. J. Great Lakes Res.
29(2): 317-331.
Marvin, C.H., M.N. Charlton, EJ Reiner, T. Kolic, K. MacPherson, G.A. Stern, E. Braekevelt,
J.F. Estenik, L. Thiessen, and S. Painter. 2002. Surficial sediment contamination in Lakes
Erie and Ontario: A comparative analysis. J. Great Lakes Res. 28(3): 437-450.
Morrison, H.A., M. Whittle, and G. D. Haffner. 2002. A comparison of the transport and fate of
polychlorinated biphenyl congeners in three Great Lakes food webs. Environ. Toxicol.
Chem. 21(4): 683-692.
Motelay-Massei, A., T. Harner, M. Shoeib, M. Diamond, G. Stern, and B. Rosenberg. 2005.
Using passive air samplers to assess urban-rural trends for persistent organic pollutants
and polycyclic aromatic hydrocarbons. 2. Seasonal trends for PAHs, PCBs, and
organochlorine pesticides. Environ. Sci. Technol. 39(15): 5763-5773.
O'Connor, T.P. 2002. National distribution of chemical concentrations in mussels and oysters in
the USA. Marine Environmental Research. 53: 117-143.
Offenberg, J.H., and I.E. Baker. 2002. Precipitation scavenging of polychlorinated biphenyls and
polycyclic aromatic hydrocarbons along an urban to over-water transect. Environ. Sci.
Technol. 36(17): 3763-3771.
Offenberg, J.H., and I.E. Baker. 2000. PCB and PAHs in southern Lake Michigan in 1994 and
1995: Urban atmospheric influences and long-term declines. J. Great Lakes Res. 26(2):
196-208.
Park, J.-S., T.L. Wade, and S.T. Sweet. 2002. Atmospheric deposition of PAHs, PCB, and
organochlorine pesticides to Corpus Christi Bay, Texas. Atmos. Environ. 36: 1707-1720.
Park, J-S., T.L. Wade, and S. Sweet. 2001. Atmospheric deposition of organochlorine
contaminants to Galveston Bay, Texas. Atmos. Environ. 35: 3315-3324.
24
-------
Rawn, D., F.K. Derek, C.G. Muir, D.A. Savoie, G. B. Rosenberg, W.L. Lockhart, and P.
Wilkinson. 2000. Historical deposition of PCB and organochlorine pesticides to Lake
Winnipeg (Canada). J. Great Lakes Res. 26(1): 3-17.
Reinfelder, J.R., L. A. Totten, and S.J. Eisenreich. 2004. The New Jersey Atmospheric Deposition
Network (NJADN) Final report to the New Jersey Department of Environmental
Protection (NJDEP). January 2004. Accessed online at
http://www.state.nj.us/dep/dsr/njadn/.
Simcik, M.F., R.M. Hoff, W.M.J. Strachan, C.W. Sweet, I. Basu, and R.A. Kites. 2000. Temporal
trends of semivolatile organic contaminants in Great Lakes precipitation. Environ. Sci.
Technol. 34: 361-367.
Stapleton, H.M., C. Masterson, J. Skubinna, P. Ostrom, N.E. Ostrom, and J.E. Baker. 2001.
Accumulation of atmospheric and sedimentary PCBs and toxaphene in a Lake Michigan
food web. Environ. Sci. Technol. 35: 3287-3293.
Sun, P., I. Basu, and R. Kites. 2006. Temporal trends of polychlorinated biphenyls in precipitation
and air at Chicago. Environ. Sci. Technol. 40: 1178-1183.
Totten, L.A., C.L. Gigliotti, D.A. Van Ry, J.H. Offenberg, E.D. Nelson, J. Dachs, J.R. Reinfelder,
and S.J. Eisenreich. 2004. Atmospheric concentrations and deposition of polychlorinated
biphenyls to the Hudson River Estuary. Environ. Sci. Technol. 38(9): 2568-2573.
Totten, L.A.,C.L. Gigliotti, J.H. Offenberg, J.E. Baker, and S.J. Eisenreich. 2003. Reevaluation of
air-water exchange fluxes of PCB in Green Bay and southern Lake Michigan. Environ.
Sci. Technol. 37(9): 1739-1743.
Totten, L.A., P.A. Brunciak, C.L. Gigliotti, J. Dachs, T.R. Glenn IV, E.D. Nelson, and S.J.
Eisenreich. 2001. Dynamic air-water exchange of polychlorinated biphenyls in the New
York-New Jersey Harbor Estuary. Environ. Sci. Technol. 35(19): 3834-3840.
Tsai, P., R. Hoenicke, D. Yee, H.A. Bamford, and J.E. Baker. 2002. Atmospheric concentrations
and fluxes of organic compounds in the northern San Francisco Estuary. Environ. Sci.
Technol. 36(22): 4741-4747.
United States and Canada. 1987. Great Lakes Water Quality Agreement of 1978, as amended by
Protocol signed November 18, 1987. Ottawa and Washington. Accessed online at
http://www.epa.gov/glnpo/glwqa/1978/index.html on March 29, 2007.
U.S. Environmental Protection Agency (U.S. EPA). 2007a. Contaminants in Top Predator Fish.
Great Lakes National Program Office. Accessed online at
http://www.epa.gov/glnpo/glindicators/fishtoxics/topfishb.htmltfContaminant%20Concent
rations%20in%20Top%20Predator%20Fish on February 27, 2007.
U.S. EPA. 2007b. 2002 National Emission Inventory (NEI) Version 3 Summary Files. March
2007. Emission Factor and Inventory Group, Office of Air Quality Planning and
Standards.
25
-------
U.S. EPA. 2006. Great Lakes Fish Monitoring Program. Great Lakes National Program Office.
Accessed online at http://epa.gov/glnpo/monitoring/fish/index.htnil on March 16, 2007.
U.S. EPA. 2005a. National Coastal Condition Report II. Office of Research and Development/
Office of Water. EPA-620/R-03/002. December 2004. Accessed online at
^^ on September 8, 2005.
U.S. EPA. 2005b. Fact Sheet: 2004 National Listing of Fish Advisories. EPA Office of Water.
EPA-823-F-05-004. September 2005.
U.S. EPA. 2003b. Fact Sheet Update: National Listing of Fish and Wildlife Advisories. EPA
Office of Water. EPA-823-F-03-003. May 2003.
U.S. EPA. 2000. Deposition of Air Pollutants to the Great Waters: Third Report to Congress.
Office of Air Quality Planning and Standards. EPA-453/R-00-0005. June 2000. Accessed
online at: hjtg^/www^epa^Qy/QaiyQaflps/gr8^gter/3j^rpt/ on September 8, 2005.
U.S. EPA. 1998. Integrated Risk Information System: Polychlorinated biphenyls (PCBs). Last
Revised on 01/02/1998. Accessed online at httpi//wwi^^
September^, 2005.
U.S. EPA and Environment Canada (EC). 2005. Great Lakes Binational Toxics Strategy
(GLBTS) 2005 Annual progress report. Accessed online at
http://binational.net/bns/2005/2005-GLBTS-English-web.pdfon February 27, 2007.
Van Ry, D., C.L. Gigliotti, T.R. Glenn, IV, E.D. Nelson, L.A. Totten, and S.J. Eisenreich. 2002.
Wet deposition of polychlorinated biphenyls in urban and background areas of the Mid-
Atlantic States. Environ. Sci. Technol. 36(15): 3201-3209.
Weseloh, D. V. Chip, C. Pekarik, S.R. De Solla. 2006. Spatial patterns and rankings of
contaminanant concetnatirations in herring gull eggs, from 15 sites in the Great Lakes and
connecting channels, 1998-2002. Environ. Monitoring and Assessment 113:265-284.
Secondary reference, as cited in IADN 2000:
Zhang, H. et al. 1999. Evidence for increased gaseous PCB fluxes to Lake Michigan from
Chicago. Environ. Sci. Technol. 33(13): 2129-2137.
Secondary reference, as cited in Morrison et al 2002:
Huestis, S.Y., M.R. Servos, D.M. Whittle, and D.GDixon. 1996. Temporal and age related trends
in levels of polychlorinated biphenyl congeners and organochlorine contaminants in Lake
Ontario lake trout. J. Great Lakes Res . 22: 310-330.
26
-------
Secondary reference, as cited in Totten et al. 2003:
Nelson, E.D., L.L. McConnell, and I.E. Baker. 1998. Diffusive exchange of gaseous polycyclic
aromatic hydrocarbons and polychlorinated biphenyls across the air-water interface of the
Chesapeake Bay. Environ. Sci. Technol. 32(7): 912-919.
27
-------
Appendix A. Detailed Breakdown of Air Emissions Inventory
Source Categories Emitting Poly chlorinated Biphenyl
Chemical Preparations3
Commercial and Industrial Solid Waste
Incineration3
Gasoline Distribution (Stage I)a
Incineration: On-site Commercial/Institutional
and Industrial
Incineration: Commercial and Industrial Solid
Waste
Industrial/Commercial/Institutional Boilers &
Process Heaters3
Inorganic Pigments Manufacturing3
Landfills - Commercial/Institutional and
Industrial
Medical Waste Incinerators3
Mineral Products: Abrasive Product
Manufacturing
Mining: Nonmetallic Mineral
Municipal Landfills3
Open Burning - Residential, Household Waste
Open Burning - Structure Fires
Other Solid Waste Incineration3
Petroleum Lubricating Oil and Grease
Manufacturing
Plastic Materials and Resins Manufacturing3
Polyethylene Terephthalate Production3
Portland Cement Manufacturing3
Printing, Coating, and Dyeing of Fabrics3
Residential Heating: Wood/Wood Residue
Combustion
Secondary Aluminum Production3
Sewage Sludge Incineration3
Solvent Use: Solvent Evaporation: Cold solvent
Cleaning
Solvent Use: Surface Coating: Auto Refinishing
and Textile Products
Site Remediation3
Stationary Reciprocating Internal Combustion
Engines3
Utility Boilers: Coal and Wood or Waste
Waste Disposal, Treatment, and Recovery
Waste Disposal: Industrial
3These source categories are associated with regulations under the Clean Air Act for stationary sources
known as maximum achievable control technology (MACT) rules.
Source: U.S. EPA 2007b
A-l
-------
United States Office of Air Quality Planning and Standards Publication No. EPA-452/R-07-012
Environmental Protection Health and Environmental Impacts Division December 2007
Agency Research Triangle Park, NC
------- |