ENVIRONMENTAL EFFECTS OF PARTICULATE MATTER

SECTION 5: ENVIRONMENTAL EFFECTS OF PARTICULATE
MATTER
This section with the environmental effects of particulate matter. We begin by recapitulating
some basic information regarding particulate matter composition and then define the scope of
this review. The main environmental effects of PM are expected to be those from acid deposition, impaired visibility, and ozone. Reduction of fine PM levels quantifiably improves
visibility and reduces ozone levels, but the effects on levels of acid deposition are unclear.
Paradoxically, the effects of acid deposition are the most well-studied. In addition, the effects
of acid deposition are widespread, affecting urban area, rural landscapes and natural
ecosystems, while problems associated with visibility and ozone are more likely to be
localized. The difficulty in assessing
the economic costs and benefits to the environment of reducing particulate matter
concentrations lies in the uncertainty of dose-response pathways as well as the difficulty of
assigning economic value to ecological systems, services and processes.

5.1 Introduction
The history of air quality management includes many examples of society’s responses to pollution. During the Middle Ages in London the ever-present cloud of dust and soot and its effects
on human health led to prohibition on coal burning. During the Industrial Revolution, air
pollution was generally considered a municipal problem rather than a public health issue and
was managed on a local level, which continued well into the 20th century. The emergence of
air pollution as a public health issue in the 1950s led to the development of federally funded
research programs, culminating in the Clean Air Act and establishment of the EPA in 1970.
Around the world, countries were developing institutional responses to combat the air
pollution
threat to human health. The effect of air pollution on ecology, however, was not yet considered
a serious issue. Having been first documented in England at the end of the 19th century, acid
rain and its ecological effects became regional issues in northwestern Europe and in the
northeastern United States in the late 1960s. The mounting anecdotal evidence of its harmful
effects on aquatic and terrestrial ecosystems launched acid rain as perhaps the first air
pollution threat to the environment to the environment to receive international attention.
Before we continue, we would like to define two basic terms. In the literature, there is often
some confusion over the use and meaning of environmental versus ecological effects.

Generally, environment refers to all aspects of one’s surroundings, both living and non-living.
Ecological effects are strictly limited to living organisms and the interactions between them. In
this section, we use environment to include urban landscapes as well as agricultural, rural and
natural areas. Our discussion of ecological effects refers only to “natural areas”, e.g. nonurban, non- agricultural systems.
As reviewed in Section 1, there are two major categories of particulate matter (PM), PM10
and
PM2.5. Particulate matter is composed of a mixture of particles directly emitted into the air
and
5-1


particles formed in the air from the chemical transformation of gaseous pollutants (secondary
particles). The principle types of directly emitted particles are soil-related particles and organic
and elemental carbon particles from the combustion of fossil fuels and biomass materials. Secondary particles are primarily ammonium sulfate and nitrate formed in the air from gaseous
emissions of sulfur dioxide (SO2) and oxides of nitrogen (NOx) reacting with ammonia (NH3)
(EPA, 1997a). In eastern urban areas, almost 50% of ambient PM2.5 levels can be composed
of sulfate, and another 10 to 15% of nitrate. Soil-related particles make up only 5% of ambient
PM2.5 levels, with combustion-related particles making up the remaining 35%. This is
markedly different from the composition of fine particulate matter (PM2.5) in other areas of
the continental
US, where most PM2.5 comes from combustion-related sources. The composition of PM10
(coarse particulate matter) in eastern urban areas differs from the composition of PM2.5
especially in the proportion of soil-related particles (31% of ambient measurements), with
correspondingly lower proportions of PM10 from combustion-related activities (26%) and
sulfate
(34%).
Like most
environmental problems, the effects of particulate matter are complex. In addition
to
the effects of the principle components (the already-mentioned directly emitted and

secondary compounds) themselves, some compounds react with other particles to form
reaction products with important effects. One of these important reaction products is
The
very different
chemical natures of the major components of PM2.5 have very different
trophospheric
ozone.
effects
on the human environment. We have identified the major effects of fine particulate matter as
being changes in visibility, acid deposition, and ozone. In the following sections, we consider
each of those effects separately. We begin by reviewing the contribution of fine PM to each of
the effects, and then discuss those effects for urban, agricultural and ecological systems. Since
the effects of acid deposition are the most acute and well-studied, we concentrate a large part
of this section to its effects in natural ecosystems, focussing on New Jersey’s most sensitive
and unique ecosystems, freshwater, estuarine and coastal waterways, and the Pine Barrens.

5.2 Acid Deposition
The fine particulate matter and acid deposition issues are closely linked in the eastern United
States. Both share the same dominance of large sulfate fraction in the chemical composition of
collected. Samples. Sulfates are a significant component of fine particles in the East and have
been directly linked to ecosystem damage. Both direct emissions of particulate matter and
secon- dary particle formation caused by oxidation of sulfur dioxide, nitrogen dioxide and
aerosol or- ganic carbon species contribute to overall levels of airborne particles. In urban
environments this greatly affects many construction materials and paints, while its effects in
agricultural and natu- ral ecosystems range from reduced productivity to disruption of nutrient
cycles to the massive summer fish kills of Chesapeake Bay and Long Island Sound observed
through the last two dec- ades.
5.2.1 Urban environment: materials
The deposition of airborne particles on the surface of building materials and culturally
important

articles can cause damage and soiling, thus reducing the life usefulness and aesthetic appeal of
5-2


such structures (National Research Council, 1979). Furthermore, the presence of particles on
surfaces may also exacerbate the physical and chemical degradation of materials that normally occur when these materials are exposed to factors such as sun, wind, temperature fluctuations and
moisture. Beyond these effects, particles, whether suspended in the atmosphere, or already deposited on a surface, also adsorb or absorb acidic gases from other pollutants like sulfur dioxide
(SO2) and nitrogen dioxide (NO2), thus serving as nucleation sites for these gases. The
deposition of “acidified” particles on a susceptible material surface is capable of accelerating
chemical deg- radation of the material. Therefore, concerns about effects of particles on
materials are related both to impacts on aesthetic appeal and physical damage to material
surfaces, both of which may have serious economic consequences. Insufficient data are
available regarding perceptions thresholds with respect to pollutant concentration, particle size,
and chemical composition to de- termine the relative roles these factors play in contributing to
materials
damage.
This
section
briefly discusses the effects of particle exposure on the aesthetic appeal and
physical
damage to different types of building materials: metals, paints, stone and cement, and then
sum- marizes these effects and their possible economic relevance. For more detailed discussion
of the effects of acid gases on materials, see the 1991 National Acid Precipitation Assessment
Program report (Baedecker et al., 1991).
Available information supports the fact that exposure to acid-forming aerosols promotes the
corrosion of metals beyond the corrosion rates expected from exposure to natural environmental
elements (see Box H). Metals undergo corrosion in the absence of pollutant exposure through
a series of physical chemical and biological interactions involving moisture, temperature,
oxygen and various types of biological agents. In addition to these environmental factors,
atmospheric pollutant exposure may accelerate the corrosion process. The rate of corrosion is

dependent on deposition rate and the nature of the pollutant, the variability in electrochemical
reactions, the amount of moisture present, the presence and concentration of other surface
electrolytes and the orientation of the metal surface.
Acid-forming aerosols have been found to limit the life expectancy of paints by causing
discolorations, loss of gloss, and loss of thickness of the paint film layer. Various building stones
and cement products are damaged from exposure to acid-forming aerosols. However, the
extent of damage to building stones and cement products produced by pollutants, beyond that
expected as part of the natural weathering process, is uncertain.
A significant detrimental effect of particle pollution is the soiling of painted surfaces and other
building materials. Soiling is defined as a degradation mechanism that can be remedied by
cleaning or washing, and depending on the soiled surface, repainting. Available data on
pollution exposure indicates that particles can result in increased cleaning frequency of the
exposed sur- face, and may reduce the life usefulness of the material soiled. Data on the effects
of particulate matter on other surfaces are not as well understood.
Several types of economic losses result from materials damage and soiling. Financial or outofpocket losses include the reduction in service life of a material, decreased utility, substitution
of a more expensive material, losses due to an inferior substitute, protection of susceptible
materi- als, and additional required maintenance, including cleaning. Economic losses from
pollutant
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exposure can be estimated using a damage function approach or using direct economic
methods.
It is, however, difficult to estimate fully the financial losses because reliable information is not
available on many economically important materials. Another major problem is the inability to
separate pollutant effects from natural weathering processes. Attempts have been made to
quan- tify the pollutants exposure levels at which materials damage and soiling have been
perceived. However, to date, insufficient data are available to advance our knowledge
regarding perception thresholds with respect to pollutant concentrations, particle size and
chemical composition.

5-4


BOX H: THE EFFECT OF ACID DEPOSITION ON MATERIALS
Iron, steel and steel alloys. The rate of corrosion is related to the amount of SO2 in the atmosphere. The rate of
corrosion
was also found to depend on the deposition rate of SO2. A separate study (Butlin et al., 1992a) showed that corrosion of
steel samples under natural meteorological conditions was highly correlated with long-term SO2 concentrations and
only minimally related to nitrogen oxides. Stainless steels, incorporating chromium, molybdenum and nickel, are highly
corro- sion resistant because of the protective properties of the oxide corrosive film.
Aluminum. Aluminum is generally considered corrosion-resistant.
Copper and copper patinas. A study in the New York area on the chemical composition of patinas concluded that
longterm corrosion of copper was not controlled by deposition of pollutants, but rather, it was likely controlled by
availability of copper to react with deposited pollutants (Graedel et al., 1987). The patina, that is mostly basic sulfate, is
not readily dissolved by acids and thus provides significant protection for the substrate metal. However, this patina can
take as long
as 5 years to form and varies with meteorological conditions. In bronze, as with many metals, dry deposition between
rain events was concluded to dominate soluble corrosion. For copper and copper alloys, though, if the patina color has
The thetic
effectsvalue,
of dust
Only limitedtheinformation
available
on the of
effects
particles
alone on metals. Barton
aesandalone.
SO2 accelerates

formation, isthen
the presence
SO2 of
may
be beneficial.
(1958)
found that dust contributed to the early stages of metal corrosion. The effect of dust was lessened as the rust layer was
formed. Other studies report that particles, by forming nuclei for the concentration of active ionic species, increase the
corrosion rate of SO2. A laboratory study of the synergistic effects of different types of particles and SOx on the
corrosion of aluminum, iron and zinc showed that four most aggressive species of particles were salt and salt/sand from
marine and de-iced locations, ash from iron smelters, ash from municipal incinerators and coal mine dusts.
Paints. Paints, opaque film coatings, are by far the dominant class of manmade materials exposed to air pollutants in
both
indoor and outdoor environments. Paints are used as decorative coverings and protective coatings against environmental
elements on a variety of finished including woods, metals, cement and asphalt. Paints primarily consist of two components: the film forming component and the pigments. Paints undergo natural weathering processes from exposure to
envi- ronmental2-factors such as sunlight, moisture, fungi and varying temperatures. Evidence exists that pollutants affect
by
2 and SO
aerosols
(PM).
Unpigmented
polymer
large rangetoofwater
permeabilities
but polymers
theSO
durability
of4paint
(National
Resources

Council,
1979).films
Painthave
filmsa permeable
are also susceptible
to used
in
penetration
paint formulations do not generally form barriers to SO2 either in the gaseous state or in solution as sulfurous acid.
There appears to be little degradation to the polymer itself from SO2 at low concentrations. A controlled exposure study
was conducted to determine the effects of gaseous pollutants on four classes of exterior paints: oil-base house paint,
vinyl- acrylic house paint, and vinyl and acrylic coatings for metals (Spence et al., 1975). SO2 and relative humidity
markedly affect the erosion of oil-based house paint. The presence of NO2 increased the weight of the paint film.
Blisters formed on acrylic latex house paint at high SO2 levels. The vinyl and acrylic coating are resistant to SO2. In
addition, the weathering of wood prior to painting decreases paint adhesion.
Automobile finishes. Reports indicate that particles can cause damage to automobile finishes. The formulation of
the
paint will affect the paint’s durability under exposure to varying environmental factors and pollution. However,
failure of the paint system results in the need for more frequent repainting and additional cost. The New York area,
which includes northeastern New Jersey, with California, has the highest costs associated with paint soiling.
Stone and cement. In general, stone containing lime is especially susceptible to the effects of acid deposition. There
can
be facilitating effects between different constituents of particulate matter. For instance, marble in cemeteries in the
Los Angeles basin showed that SO2 is more reactive with the calcium in marble under high NO2 conditions.
Soiling. An additional, significant and detrimental effect of particle pollution is the soiling of man-made surfaces. The
black crust found in the protected areas of buildings is formed from a hard crust of gypsum mixed with dust, aerosols
and carbonaceous particles. Increased frequency of cleaning, washing or repainting over soiled surfaces becomes an
economic burden and can reduce the life usefulness of the material soiled. A study of repainting frequency and
particulate concentration found that houses in Steubenville, OH, where PM concentrations average 235 µm per year, needed to be
repainted every year. Fairfax, VA, on the other hand, had a mean annual PM concentration of 60 µm/m3; the time

between re- painting was generally 4 years.

5-5


5.2.2 Acid deposition and natural ecosystems in New Jersey
New Jersey consists of 19% wetlands and 42% forest area. Its five physiological regions
(Figure
5-1) sustain a wildlife abundance and diversity that is exceeded only by a few states. Within
the course of a year over 430 bird species can be sighted, ranking the state species list as
fourth in the nation, surpassed only by the much larger states of Texas, California, and Florida.
New Jer- sey has more than 75 mammal species and over 40 species of reptiles and
amphibians. Because of its latitude, the state has an extraordinary blend of northern and
southern animal and plant species that reach their limit of the ranges here. Because New Jersey
is the fourth smallest and
most densely populated state in the nation, many environmental problems surface and need to
Today,
airhere
pollution
is a major
be solved
first (Kane
et al,global
1992).environmental problem. In Europe about half the air
pollution crosses borders and kills fish, trees and corrodes buildings and monuments. Governments
in Europe have responded to this problem by collaborating within the Long-Range
Transboundary Air Pollution (LRTAP) Convention, as well as by taking measures within the
European Commu- nity and at the national level (Levy, 1993). Central to the work plan is the
idea to use critical loads as the basis of LRTAP protocols in order to manage transborder
pollutants. A critical load is defined as “a quantitative estimate of exposure to one or more

pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according
to the present knowledge”. Critical loads focus negotiators’ attention on scientific issues. Using
dose-response data on soils, vegetation and freshwaters, national focal centers are
preparing critical load maps for sulfur nitrogen and total acidity. Critical loads vary a great
deal across
Europe because ecological sensitivity is highly dependent on geology and weather conditions.
Therefore in order to determine the critical load, each country focuses on its most sensitive
The
deposition
on idea
sensitive
can range
from
daysand
to centuries.
Ecosystems
eco- effects
system.ofWe
apply this
to thereceptors
ecosystems
of New
Jersey
focus on what
we think
are
are the most sensitive ecosystems in the state: aquatic ecosystems and the Pine Barrens.
complex systems that are simultaneously responding to a variety of inputs, such as climate,
land- use patterns and other pollutants besides sulfur and nitrogen oxides. These multiple
stressors can result in chemical changes within the ecosystem, which can exhibit long lag times

before mani- festing a response. Therefore, in many effect areas, responses to current
reductions will not be expected for many years. Monitoring the changes in the effects areas
over time will be necessary to determine whether the expected benefits are realized.
5.2.3 Aquatic ecosystems
The following section describes the basic chemical principles behind how acid deposition produces the observed effects in aquatic systems. Due to the different chemical properties of fresh
and salt water, the major observed effects of acid deposition in freshwater and saltwater
systems are fairly different and are treated under separate subheadings.

5-6


Figure 5-1. Physiographic Regions of New Jersey

5-7


If there is a change in the concentration of an anion contributed by acid deposition (e.g., sulfate
or nitrate), then other anions and/or cation concentrations must also change, such that the total
concentration of anions always equals the total concentration of cations in the surface water.
This is called the principle of electroneutrality, whereby positive and negative ions are found in
equal amounts. Thus, if acid deposition causes sulfate and nitrate concentrations to increase,
then some or all of the following changes will also occur:
•

Bicarbonate anion decreases, which causes a reduction in acid neutralizing
capacity
• Base cations (calcium, magnesium, sodium, potassium) increase, which prevent
or
minimize acidification of drainage waters, but may deplete soil reserves and
affect forest growth

• Hydrogen cation increases (decrease pH), which can adversely affect aquatic
biota
• Aluminum cation increases which can negatively affect aquatic
biota
If a reduction in acid deposition causes sulfate and nitrate concentrations to decrease, the
changes opposite to those enumerated above will also occur. An increase in the concentration
of base cations in drainage waters as a consequence of acid deposition has both positive and
nega- tive connotations. Removal of base cations from soils to balance sulfate or nitrate from
acid deposition minimizes the extent of surface water acidification. Over time, however, base
cation reserves in the soils can become depleted if they are lost from the soils faster than they
are sup- plied from atmospheric inputs and weathering. This can delay acidification recovery
(NAPAP, 1998).
Although it is too early to detect specific changes in aquatic systems from emission reductions
under Title IV, significant progress has been made since 1990 in refining understanding of the
acidification process and quantifying dose-response relationships. This information improves
model forecasts of anticipated change in aquatic systems due to reduced emissions. Particular
areas include naturally occurring organic acidity, the depletion of base cation reserves from
soils, nitrogen dynamics in forest and alpine ecosystems, interactions between acid deposition
and land use, and the role of aluminum in fisheries response.
Rivers, streams and lakes
The concentration of sulfate in surface waters has decreased in many lakes and streams over
the
past 10-20 years. This decrease has been caused by reductions in emissions and subsequent decreases in atmospheric deposition of sulfur on a regional basis in the United States during that
period. In parts of the northeastern United States, approximate reductions of 15% in sulfate
con- centrations of lakes and streams have been measured in recent years (NAPAP, 1998) .
Sulfate concentrations are expected to continue to decline in the Northeast. Exactly how that
will affect surface water acidity and biological recovery is uncertain and will require continued
monitoring. On the other hand, lakes in New England do appear to show statistically
significant recovery in acid-neutralizing capability as a result of sulfate reductions. However,
the majority of Adiron- dack lakes have remained fairly constant, while the sensitive

Adirondack lakes continue to acid- ify (Bulger et al., 1998).
5-8


Concurrent changes in the concentrations of other chemical parameters have been generally less
clear and less consistent than for sulfate and base cations. There other parameters are more
strongly influenced by factors other than atmospheric deposition. Concentrations of key
chemical parameters often vary per season by more than can be accounted for by acid
deposition. Seasonal variability is particularly problematic in determining long-term trends.
Continued monthly monitoring of different types of lakes and streams located in sensitive
regions will provide much needed data on seasonal variability.
Adverse effects on fish populations and communities of chronically acidified streams comes
from Shenandoah National Park (Virginia). Fish species richness, population density,
condition factor, age distribution, size and bioassay survival were all reduced in streams with
low acid- neutralizing capacity, as compared to those with intermediate and high acid
neutralizing capa- bilities (Bulger et al., 1998).
A study of 13 streams in the Adirondack and Catskill Mountains showed long-term adverse
episodic effects on fish populations. Streams with suitable chemistry during low flow, but low pH
and high aluminum levels during high flow, had substantially lower numbers and biomass of
brook trout than were found in nonacidic streams. Streams having acidic episodes showed significant fish mortality. A study of coastal plain streams indicated that larval mortality of river
herring due to episodic acidification may be substantial during wet years, which exhibit more
frequent and severe episodes. Episodic acidification may also be relevant to certain kinds of
lakes, depending on the magnitude and duration of the spring snowmelt period. Rainbow trout
are sensitive to acidification not because of acidity itself, but because of elevated aluminum
con- centrations due to low pH levels (lower than 5.0). Aluminum accumulates on gills and
disrupts gill ion transport and respiratory function (NAPAP, 1998).
Estuaries and near-coastal waters
It is now obvious that ammonium and nitrate deposition are central concerns to the health of
coastal ecosystems. Although these species are major contributors to acid deposition, their
main environmental consequence is eutrophication of coastal waters. The problem is not just

deposition to the water bodies themselves, but the transport of airborne nitrogen species through surrounding watersheds, streams, ground water into the water bodies that become overenriched
with
nutrients. Depending on the water body in question, atmospheric deposition is likely to
Nitrogen
is the
limiting
nutrientof
forthe
thetotal
growth
of algae
in many
estuaries and near-coastal sysaccount for
as much
as 30-40%
nutrient
loading
received.
tems, rather than phosphorus, which typically limits algal growth in freshwater systems.
Chesa- peake Bay is the nation’s largest estuarine system, with a watershed of almost 64,000
square miles, encompassing one-sixth of the Eastern Seaboard. The Bay has an important fish
and shell- fish industry and serves as a nursery for marine commercial and sport fish. There has
been con- siderable research and monitoring on the effects of nitrogen and phosphorus loading
to Chesa- peake Bay. New Jersey’s southern shore borders Delaware Bay, which has
experienced many problems similar to those of the Chesapeake. Changes in atmospheric
nitrogen deposition can have significant impacts on aquatic biology. Excess nitrogen entering
the Bay produces algal blooms that block sunlight needed for submerged aquatic grasses, and
the decomposition of ex- cess algae depletes life-sustaining oxygen needed by invertebrates
inhabiting bottom waters. The best estimates of atmospheric nitrogen loads to Chesapeake Bay
and other estuaries along the

5-9


Atlantic and gulf Coasts range from 10% to 45% of the total nitrogen inputs from all
sources.
Additional research is needed to quantify the current effects and the expected benefits from
re- ducing nitrogen deposition on estuary systems.
5.2.4 New Jersey Pine Barrens
The Pine Barrens of New Jersey are unique and of global interest. The Pine Barrens region, or
Pinelands, is a large, mostly forested region that harbors many unique plant and animal
species. Ecologically, it consists of some 2000 to 2250 square miles of generally flat, sandy,
acidic, and sterile soils which constitute a major part of the Outer Coastal Plain section of the
Atlantic Coastal Plain in New Jersey (Boyd, 1991). For a detailed description of this
ecosystem see For- man (1979). In addition to agriculture, some of the principle uses of the
Pine Barrens are recrea- tional: camping, canoeing, hiking and hunting. Another important use
is valuable scientific re- search.
The possible impacts of acid deposition on the vegetation of the Pine Barrens, and upon plant
and animal life in its streams are currently under study by the Division of Pinelands Research at
Rutgers University. The nature and source of acid rain is changing the type of acidity in Pine
Barrens streams from organic to mineral. This is shown by increased levels of sulfate in the water and decreased concentrations of dissolved organic matter. The acidity characteristic of soils
in the Pine Barrens is created when decaying vegetation produces an organic acid that washes
down through and is absorbed by sandy soils. These organic acids leach out aluminum found in
Pine- land soils, making it harmless in Pine Barren waters. However, the sulfuric acids in acid
rain do not bond with aluminum, so this mineral is washed, in its pure form, into streams
(Morgan, 1984). It is concluded that the pollution caused by these increased sulfates, nitrates,
and alumi- num may be toxic to aquatic life, but long-term effects of this pollution are
unknown at this time (Section 5.4.3.1 discusses the toxic effects of aluminum on fish in
freshwater streams). Acid deposition has also been shown to increase levels of mercury and
nitrate in pine needles and
other vegetation. Animals eating this vegetation will tend to concentrate those toxic compounds

in their body tissues, possibly increasing mortality. While the physiological pathways for increased plant adsorption of these toxins are well-known, the mechanism by which they
accumu- late in animals and the effects on morbidity and mortality have not been rigorously
demonstrated and await further scientific evidence.
Significant impacts of acid deposition on forest health have not been detected in the southern
pine and pine-hardwood region, to which the New Jersey Pine Barrens are similar. However,
acid deposition is a major contributor to the depletion of base cations in many poorly buffered
soils supporting southern pines and will, most likely, over the long term (decades), impede
pro- ductivity. Short-term positive effects on growth are expected for some nitrogen-deficient
soils, while negative effects are expected to be limited to the most acidic, base-depleted soils.
A synthesis of studies that originated as part of a NAPAP to evaluate the sensitivity of
southern
pines to acid deposition and ozone has now been completed. In chamber studies, saplings of
the three principle commercial pine species (loblolly, shortleaf, and slash pine) were exposed
to simulated acid rainfall and ozone. Maximum annual growth reductions in saplings due to
due to ambient ozone were quite small (2-5%), but the yield could be significantly reduced
over the longer time frames. Growth rates of saplings typically responded positively to
ambient levels
5-10


acid rainfall. However, longer-term exposures are expected to have cumulative negative effects
on soil nutrition. While these impacts will most likely have negative long-term consequences,
the inputs of atmospheric sources of nitrogen to many soils with low nitrogen reserves should
have small cumulative positive effects on productivity for as long as decades (NAPAP, 1998).
5.2.5 Trends in acid deposition
Title IV of the 1990 Clean Air Act Amendments (CAAA) requires the reduction of acid rain
precursors—namely, emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from electric
utilities. Emissions of SO2 in the United States have decreased significantly since the
enactment of Title IV of the Clean Air Act, from 26 million tons per year in 1980 to18 million
tons in 1995. Most, if not all, of those reductions in SO2 emissions have come from reductions

in the emis- sions of Phase I utilities, especially electric utilities. Seasonal trends in fineparticulate sulfur show increases for the summer months and slight decreases during the winter
in Great Smokey Mountains and Shenandoah National Parks from 1982 to 1994. Total Sulfur
Ambient Air Con- centrations from 1989 to 1995 have decreased an average of 30% (NAPAP,
1998). While annual mean pH of precipitation in New Jersey continues to be very low (4.3), the
total annual deposi- tion of sulfate ions (kg/ha) is below the threshold considered to be
detrimental to natural ecosys- tems (20 kg/ha).
Analysis of the 1995 wet deposition monitoring data demonstrates that the 1995 reduction in
SO2 emissions in the Midwestern and northeastern United States resulted in a substantial
reduc- tion of the acidity and sulfate concentration of precipitation in those regions. Unlike
sulfate and hydrogen ions, nitrate concentrations in 1995 were greater than estimated
concentrations at most of the sites in the eastern and western regions of the country. This is not
unexpected, since im- plementation of Title IV NOx reductions only began in January 1996.
In 1995, dry deposition rates of sulfur at State College, Pennsylvania, decreased to their lowest
rates since 1986. Deposition rates of nitrogen have slowly increased. Current capabilities for
un- derstanding the processes controlling dry deposition are still exploratory. Work conducted
in the United States on dry deposition of SO2 indicates that the historic evaluation of dry
deposition of gaseous sulfur may underestimate actual rates, perhaps as much as 15-20%,
depending on the site.

5-11


5.3 Visibility
The National Research Council’s Committee on Haze in National Parks and Wilderness
Areas
said, “Visibility is the degree to which the atmosphere is transparent to visible light.”
Section 169A of the 1977 Clean Air Act (CAA) Amendments (42 U.S.C. 7491) and the 1979
Report to Congress (U.S. Environmental Protection Agency, 1979) define visibility
impairment as a re- duction in visual range and atmospheric discoloration. Equating visibility
to the visual range is consistent with historical visibility measurements at airports, where

human observers recorded the greatest distance at which one of a number of pre-selected
Visibility
maybealso
be defined as the clarity (transparency) and color fidelity of the
targets could
perceived.
atmosphere.
Transparency can be quantified by the contrast transmittance of the atmosphere. This
definition of visibility is consistent with both (1) the historical records based on human
observation of the perceptibility of targets, which include both the longest duration and most
widespread records now available, and (2) the definition of visibility recommended by the
National Research Coun- cil.
5.3.1 Air pollution and visibility
Air pollution can also alter the colors of the atmosphere and the perceived colors of objects
viewed through the atmosphere. A complete quantification of visibility should include a
measure of the color changes caused by the atmosphere. Such measures have been included in
plume visibility models, but there is no consensus on the best parameter to quantify color
changes caused by air pollution from many sources.
The perception of color depends on illumination and setting. For example, when there is a brilliant sunset, a white picket fence will appear to be white, but will be distinctly yellow in a
photo- graph. A nitrogen dioxide-containing plume appears to be yellow against a blue sky
even when a photograph or spectral measurement shows that the plume is blue, but less blue
than the sur- rounding sky. The eye correctly perceives that a yellow gas is present in the
plume. These prop- erties of human vision have been explored elsewhere (EPA, 1997d).
One way to measure the effect of particulate matter on visibility is to measure the light
scattering
efficiency of particles. The higher the light scattering efficiency, the less light from any given
object reaches an observer’s eyes, decreasing visibility. The light-scattering efficiency differs
considerably for fine and coarse particles, ranging from 2.4 to 3.1 m2/g for fine particles and
0.2 to 0.4 m2/g for coarse particles (EPA, 1997f). Larger light-scattering efficiencies for fine
parti- cles have been observed when significant numbers of the particles are in the 0.5 to 1.0

µm size range. The great majority of light absorption by particles is caused by elemental
carbon. Deter- minations of the mass-specific light-absorption emission of elemental carbon
give values in the range of 9 to 10 m2/g. Great reductions in visibility occur when water
condenses to form fog or clouds. Water is also present in all ambient particles, even on
relatively clear days. The increase in the amount of water in particle phase that occurs at high
relative humidity (RH) has a signifi- cant effect on visibility. Light-scattering efficiency of
fine particles also increase with high RH, and ammonium sulfate particles are an aerosol
component that contributes to the absorption of
5-12


water at high RH. Thus, fine particles cause more visibility problems than coarse particles,
and
on hot, humid days exasperate conditions that lower visibility.
Particulate sulfate found in the atmosphere by the conversion of SO2 is responsible for 4065%
of the haze in the eastern United States, based on a combination of measurements and calculations. Nitrates contribute 6-14% of the haze on an annual average basis, with much lower
contri- butions in summer (less than 5%) than in winter (almost 30%). Nitrate concentrations
in urban areas are generally higher than in surrounding rural areas as a result of the influence
of urban
Economic
studies
have estimated values for two types of visibility effects potentially related to
transportation
sources.
particulate matter and NOx: (1) use and non-use values for preventing the types of plumes
caused by power plant emissions, visible from recreation areas in the southwestern United
States; and
(2) use values of local residents for reducing or preventing increases in urban haze in several
dif- ferent locations.
In the eastern United States, the accepted value for natural visibility is between 60 and 80

miles.
From 9 to 12% of visibility reduction in these states comes from natural vegetation; 60 to 70%
of anthropogenically-induced visibility impairment is estimated to come from sulfates, while
car- bon-based compounds contribute roughly 20%. In urban areas, nitrates are thought to be
more important than in rural areas (Anon, 1994). While visibility is lower during the summer
months, the relative contribution of different particle species does not vary with season.
In the long-term, mean visibility has steadily decreased in the eastern states for all seasons
since
1970. Visibility during the summer months is significantly affected, with mean visibility
less than 10 miles for all states east of the Mississippi (Anon, 1994).
5.3.2 Haze in protected natural areas
In August 1977, Congress amended the Clean Air Act (CAA) to establish as a national goal
“the
prevention of any future and remedying of any existing impairment of visibility in mandatory
Class I Federal areas, which impairment results from man-made air pollution” (Title I Part C
Section 169A; 42 U.S.C. 7491). Class I areas include many national parks and wilderness areas,
including Brigantine Federal Wildlife Refuge in Southern New Jersey. The mandate to protect
visibility in national parks and wilderness areas led to the development of the Interagency
Monitoring of Protected Visual Environments (IMPROVE), a cooperative visibility monitoring
network managed and operated by federal land management agencies, the U.S. EPA and State
air quality organizations.
In National Park Service (NPS) studies during the summers of 1983, 1984, and 1985, visitors at
Grand Canyon, Mesa Verde, Mount Rainier, Great Smoky Mountains, and Everglades National
Parks were given a list of park features and asked how important each one was to their recreational experience. At each of the five parks, "clean, clear air" was ranked among the top 4 features. For example, 82 percent of the 638 respondents at Grand Canyon rated "clean, clear air"
as "very important" or "extremely important" to their recreational experience.

5-13


The Grand Canyon Visibility Transport Commission is currently conducting a

comprehensive
study on the economic impact of visibility impairment on national parks and wilderness
areas and the cost of controls. Several studies have estimates on-site values for preventing an
air- pollution plume visible from recreation areas in the southwestern United States. The
estimated on-site use values for the prevention or elimination of the plume ranged from $3
to $6 (1989 dollars) per day per visitor-party at the park. A potential problem common to all
studies is the use of daily entrance fees as a payment vehicle.
That people notice changes in visibility conditions, and that visibility conditions affect the
wellbeing of individuals, has been verified in scenic and visual air quality rating studies, through
ob- servation that individuals spend less time at scenic vistas on days with lower visibility and
through use of attitudinal surveys (Ross, 1988; EPA, 1997f). In New Jersey, this probably
affects revenue from tourism, especially for sites such as Barnegut Lighthouse in Cape May
County and Liberty Island State Park in Jersey City.
Edwin B. Forsythe Federal Wildlife Refuge (FWR), formerly known as the Brigantine FWR,
is
one of few IMPROVE sites in the eastern United States and the only such site in New Jersey.
Unfortunately, visibility data from the monitors is not currently available. New Jersey’s
Depart- ment of Environmental Protection does take smoke shade information, which shows
that visibil- ity problems are concentrated in the northeast of the state (Figure 5-2). However,
the correlation of this data with fine particulate matter levels is unclear. Section 4.6, Effects
and Benefits, pres- ents trends observed in the eastern United States and relates them to CAAA
effects.
5.3.3 Urban haze
Interest in protecting visibility in urban areas has a long history and is strong in today’s society.
Smoke in European cities, especially London, has been a concern for centuries. Many of the
modern advances in the understanding of fine particles were made during the 1969 Pasadena
Smog Experiment (Whitby et al., 1992). The continuing interest in urban visibility is indicated
in the list of short-term intensive visibility and aerosol studies summarized by the National
Acid Precipitation Assessment Program (NAPAP) Report on Visibility (Trijonis et al., 1991).
Visibil- ity, while an important aesthetic aspect of urban environments, could be an important

factor in
air traffic problems.
A study based on answers to direct willingness to pay questions in Eastern cities (Chicago,
Atlanta, Boston, Washington, D.C., Miami and Cincinnati) showed that households were
willing to pay $8 to $51 (average $18) a month for 14% average improvement in visibility
alone (Tolley et al., 1986).

5-14


Figure 5-2. State of New Jersey Average Smoke Shade, 1996

5-15


5.3 Ozone
At ground level, ozone is created by a chemical reaction between oxides of nitrogen (NOx),
and
volatile organic compounds (VOC) in the presence of sunlight. Ozone is a gas that forms in
the atmosphere when 3 atoms of oxygen are combined (O3). Ozone has the same chemical
structure whether it occurs high above the earth or at ground level and can be "good" or "bad,"
depending on its location in the atmosphere.
Ozone occurs in two layers of the atmosphere. The layer surrounding the earth’s surface is
the
troposphere. Here, ground level or "bad" ozone is an air pollutant that damages human
health, vegetation, and many common materials. It is a key ingredient of urban smog. The
troposphere extends to a level about 10 miles up, where it meets the second layer, the
stratosphere. The stratospheric or "good" ozone layer extends upward from about 10 to 30
miles and protects life on earth from the sun's harmful ultraviolet rays (UV-B).
Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents are

some
of the major sources of NOx and VOC, also known as ozone precursors, and significant
compo- nents of fine PM. Strong sunlight and hot weather cause ground-level ozone to form in
harmful concentrations in the air. Many urban areas tend to have high levels of ground-level
ozone, but other areas are also subject to high ozone levels as winds carry NOx emissions
hundreds of miles away from their original sources.
Ozone concentrations can vary from year to year. Changing weather patterns (especially the
number of hot, sunny days), periods of air stagnation, and other factors that contribute to
ozone formation make long-term predictions difficult.
5.4.1 Effects of ozone on ecosystems
Ground-level ozone interferes with the ability of plants to produce and store food, so that
growth,
reproduction and overall plant health are compromised. By weakening sensitive vegetation,
ozone makes plants more susceptible to disease, pests, and environmental stresses. Groundlevel ozone has been shown to reduce agricultural yields for many economically important
crops (e.g., soybeans, kidney beans, wheat, and cotton). In the United States, this is worth an
estimated 500 million dollars in reduced crop yield each year. The effects of ground-level ozone
on long-lived species such as trees are believed to add up over many years so that whole forests
or ecosystems can be affected. For example, ozone can adversely impact ecological functions
such as water movement, mineral nutrient cycling, and habitats for various animal and plant
species. Ground- level ozone can kill or damage leaves so that they fall off the plants too soon
or become spotted or brown. These effects can significantly decrease the natural beauty of an
area, such as in na- tional parks and recreation areas.

5-16


5.4.2 Trends in ozone
Between 1980 and 1997, between 6 and 60 days per year have exceed the ozone limit New
Jersey, although that number of days has decreased steadily in that time period. This is largely
due to ozone-related summertime nitrogen oxide controls.

Nitrogen oxides and volatile organic compounds are the primary precursors of trophospheric
ozone. As a result of oxidation reactions in the atmosphere, these compounds form ozone.
These same oxidation reactions convert sulfur oxides and nitrogen dioxides to their sulfate and
nitrate forms, leading to acid deposition. Research contributing to the understanding of ozone
chemistry, transport and fate will be critical in interpreting the results of sulfur dioxide and nitrogen
oxide controls to reduce acid deposition. It will be important to know how controls of these
compounds have interacted to produce beneficial results in environmentally sensitive regions,
and to be able to distinguish between their relative contributions. Trophospheric ozone and
acid deposition both have nitrogen oxides in common. Understanding their sources and sinks
will be important in resolving those issues. An important question to address in the future will
be the degree to which ozone-related nitrogen-oxide controls also mitigate acid deposition and
coastal eutrophication problems.

5.5 Effects and benefits
Economic methods for valuing the effects of pollution on marketed goods and services have
been
available for many years. The ability to estimate benefits for these effects is limited by the
avail- ability of economic and scientific data. In contrast, methods for estimating the nonmarket values and passive-use values have only recently become widely used and accepted.
Market goods and services in this case include agriculture and commercial forests and
materials.
Non-market goods and services are those associated with aquatic and forest recreation and
visi- bility. By nonuse values we mean ecosystem health and cultural resources.
5.5.1 A general overview
The 1998 NAPAP Biennial Report to Congress analyzes benefits associated with each sector
and
the expected effects of further reductions to each sector. In general, quantifiable benefits are
relatively large in the areas of health and visibility. The main problem in both materials and
cul- tural resources valuation is the lack of a complete information in all areas: an inventory of
af- fected assets, economic lives of assets, change in associated human behavioral responses to
dam- age. Ecosystem changes associated with Title IV reductions in emissions cannot yet be

deter- mined. The science-to-economics links for fishing, boating and swimming are not yet
well- developed, but are better for the northeastern United States than in the rest of the country.
There
is ample evidence of the effects of sulfur, nitrogen and ozone on forests. A key concern is the
decline of forest resources. However, the link between primary pollutants and the effects that
people may care about most, such as foliage intensity and range, is not established. A variety
of confounding factors, such as drought and introduced pests, has made it difficult for forest
re5-17


searchers to quantify the relationship between air pollution levels and forest decline.
Susceptibility to these factors may well be associated with forest health. Of all air pollutants, ambient
ozone is likely to cause the most significant crop damage. Dose-response functions for ozone
are avail- able for most major agronomic crops and some specialty crops. NOx reductions are
believed to decrease the creation of ozone and damage to agriculture (NAPAP, 1998).
As a result of emission reduction, potentially significant benefits may be achieved in the areas
of
visibility and materials. As preliminary evidence discussed earlier indicates, reasonable
estimates of benefits to materials and cultural resources are not available. With regard to
visibility, in one study standard visual range with and without Title IV was compared to assess
the economic benefits of improvements in visibility. Drawing on several previous survey
studies to value changes in visibility, substantial monetary benefits were obtained for
residential areas in 31 east- ern states and for national parks in the southeastern United States.
Benefits to this region were estimated to be $3.4 billion (1994 dollars) in 2010, or about $377
per ton of SO2 emission reduc- tion. Alternative scenarios predict median visibility benefits for
improvements at $118 to $224 per ton of SO2 reduction. Visibility changes vary in a nonlinear
fashion with emission changes, resulting in the variation in benefits per ton. Benefits at
residential sites were found to be of sub- stantial magnitude.
Reasonable estimates of potential ecosystem (non-use) benefits are not available at this time.
Ecosystem health benefits are expected to be large in part because they encompass broad

changes that affect many environmental end points, perhaps to a small degree, but that taken together could alter large-scale systems. Aquatic and terrestrial effects are likely to have
significant benefits through non-use values, but uncertainties around those values remain the
largest.
5.5.2 Effects for New Jersey
What do these figures mean for New Jersey? In this section we have reviewed the basic
mechanisms of how problems associated with fine particulate matter have complex effects in the
natural environment, differentiating between the urban areas of northeastern and central-west
New Jersey, and rural areas, especially southern New Jersey. The major effects of air pollution
are not just limited to the effects of primary particles, but also to secondary products of
airborne compounds that form particulate matter. As we have stressed throughout the section,
the very different chemical natures of the components of PM2.5 mean that their effects in
natural systems also differ greatly. We identify three major effects of particulate matter:
• acid deposition
• changes in visibility
• ozone
We also stress that the lack of scientific information and long-term data (which is in the
process
of being collected) makes it extremely difficult to make exact predictions and economic arguments regarding the effects of particulate matter, and on the possible effects of changing their
regulation standards. However, just to highlight the possible magnitude of these impacts, it
may be useful to consider the industries that are affected by the effects of particulate matter.
5-18


Increased visibility is the most well-understood and predictable effect of changing particulate
matter standards. Changes in visibility have been hypothesized to affect airport operations.
Based on a study conducted by the U.S. EPA (1985), the percentage of the visibility impairment
inci- dents sufficient to affect air traffic activity might be attributable in part to man-made air
pollut- ants (possibly 2 to 12% in the summer for the eastern United States). Lowered visibility
was seen to lower the amount of time and the amount of money that tourists spend in the Grand
Canyon. This result probably similar at some New Jersey tourist destinations, for instance,

Liberty State Park in Jersey City. Jersey City is also the site in New Jersey with the highest
average annual Coefficient of Haze. Liberty State Park is one of the most visited tourist sites in
New Jersey.
Since New Jersey Smoke Shade measures (Coefficient of Haze) are not comparable to the
Grand Canyon “deciview” units of visibility, we cannot directly attribute economic benefits to
increasTourism
in New
Jersey
is worth slightly more than $25 billion dollars annually. New Jersey is
ing visibility
at these
sites.
a
well-known birding site, being a major stop on the eastern seaboard migration route,
especially for seabirds and neotropical migrants (among which include several endangered
species). This sector of tourism would be affected severely by ecosystem degradation, due to
acid deposition and ozone damage. We have shown that acid deposition affects materials,
increasing mainte- nance and replacement costs.
Ecosystem degradation would also affect the agriculture and fisheries sectors. New Jersey is
home to some of the largest commercial and recreational fishing ports on the Eastern Coast. In
1995, New Jersey commercial fisherman harvested over 177 million pounds of fish and
seafood valued at over $96 million. The state’s fledgling aquaculture industry contributed an
additional farmgate value of $4 million. It is estimated that the commercial and seafood
industries contrib- uted approximately $624 million to the economy of the Garden State in
1995 with an additional
$762.2 million generated by the recreational fishing industry. Signs of decline already exist,
and show signs of improvement with stringent monitoring and clean-up efforts over the last 40
years. After dramatic crashes in fish populations in the early 80s, the Delaware River and
Estuary has shown increases in the abundance of several major fisheries in recent years,
including striped bass, weakfish, and American Shad. However, even these current levels for

fish abundances are still significantly lower than those a century ago, some times as much as
two orders of magnitude in the case of the Atlantic sturgeon.
Cash receipts from farms totaled $773 million in New Jersey in 1997. The largest part of this
figure comes from the nursery/greenhouse/sod industry ($257 million), followed by vegetables
($169 million). Other important sectors were equine ($115 million), fruit ($86 million), field
crops ($60 million), dairy ($42 million) and poultry and eggs ($36 million). While an estimate
of agricultural losses due to air pollution and fine particulate matter is impossible at this time,
we might begin by looking at the effects of ozone on agricultural production. The effects of
ozone
on production are well documented for many agricultural crops. Since the precursors to ozone
are the same particles that contribute to particulate matter, we feel that this may provide a good
estimate for the order of magnitude for agricultural losses due to air pollution. Agriculture in
the United States produced a little over $86 billion in agricultural crops alone in 1997. Ozone
dam- age is estimated to cause losses of $500 million to agricultural crops alone, which works
out to
5-19


0.5% of agricultural crop production. Assuming that ozone decreased the production of only
agricultural field crops and not vegetables, fruits and nuts, or any other agricultural and farm
prod- uct, and extrapolating from national figures for agricultural losses, this implies a loss of
a $350 thousand per year. If this were to include all principal crops then losses for New Jersey
could be on the order of $1.6 million per annum. All of the above estimates are upper bounds
on the pos- sible economic effects of particulate matter. However, as we have seen above, the
effects of par- ticulate matter in ecosystems are not simple relationships, and biological and
ecological path- ways often magnify and accumulate pollutants and their effects such that
results are only observ- able after long time delays. The following paragraphs address this
concern.
In order to examine the question of “threshold” effects in ecosystems and the possible effects
of

the new fine PM standards, we outline the possible effects of reduced nitrogen and sulfur
depo- sition in surface water, soils and forests (NAPAP, 1998). Since biological responses to
changes in acid-base chemistry are along a continuum, there is not a single value or set of
chemical concentrations that represent a threshold for significant adverse biological effects. We therefore
Adverse
ecological
are any injury
(i.e.ofloss
of chemical
have a difficult
taskeffects
in determining
the level
acceptable
risk.or physical quality or viability)
to
any ecological or ecosystem component, up to and including at the regional level, over both
long and short terms. Using this working definition we are interested in looking at a doseresponse relationship along a continuum of ecological effects.
The main question of interest therefore is: as the dose of air pollution (specifically sulfur and
nitrogen emissions and its subsequent formation of acid deposition) is reduced, how do aquatic
and terrestrial ecosystems respond?
We know that both nitrogen and sulfur deposition are important contributors to chronic and
episodic acidification of surface waters. Further reductions in nitrogen as well as sulfur
deposition may be necessary to fully protect targeted sensitive systems.
The literature search for this project has shown us that there is still much research to be done if
we are to protect sensitive ecosystems appropriately. It is this lack of knowledge that has
limited the EPA’s ability to recommend specific deposition standards.
The Nitrogen Bounding Study (Van Sickle & Church, 1995) illustrates the modeled results of
scenarios of potential future nitrogen and sulfur deposition rates and different watershed
nitrogen retention conditions and their combined effects on surface water chemistry at regional

scales.
The main results suggest that sulfur deposition is likely to remain the primary acidification
problem in the most sensitive areas of eastern North America. Additionally sulfur and
nitrogen
are projected to have approximately equal roles in surface water acidification. For most areas
where current or near-term needs for additional controls are projected, and where watershed
nitrogen saturation is not likely imminent, the greatest potential benefits will come primarily
from control of sulfur emissions and deposition. In regions where nitrogen deposition is now or
would
likely become a more direct cause of chronically acidic conditions in sensitive waters, with po5-20
tential effects of sulfur and nitrogen deposition
becoming approximately equal and directly
addi-


tive, further limits on nitrogen deposition could produce a twofold impact by both reducing
acid
deposition rates and lengthening average times to watershed nitrogen saturation.
Scientific uncertainties regarding varying regional rates and differences in processes affecting
watershed assimilation of acid-forming sulfur and nitrogen compounds preclude quantifying the
reduction in deposition of either chemical below which there would be no significant adverse
impact. Available information indicates that additional decreases in deposition would reduce
re- gional proportions of chronically acidic surface waters or proportions of surface water most
sen- sitive to episodic effects. The magnitude of these potential benefits to each group of
surface wa- ters varies considerably by region. Deposition reductions could benefit 20% or
more of the acidic or sensitive waters. However, even a few percentage points may mean that
many lakes or miles
of stream reaches are benefiting.
The acid-base chemistry of the soils and the water draining forest soils will depend on the characteristics and sensitivity of the soils. A recent study has shown that New Jersey’s soils have a
high probability of experiencing a delayed or future response to acidic deposition (Turner et

al., 1986). In general, decreasing the input of sulfur and nitrogen from deposition will decrease
sul- fate and nitrate levels in soils and soil water. The timing of this decrease in soil and soil
water sulfate depends on the amount of sulfur stored. Soils high in sulfur will most likely
experience a slower decrease in soil water sulfate, as the soil slowly releases stored sulfur. For
nitrogen, the timing of the decrease will depend on the amount of nitrogen stored and the
growth needs of the forest. A forest that has high demand for nitrogen, relative to the nitrogen
storage and through- put, will experience smaller decreases in nitrogen in soil water in
response to decreased nitrogen deposition compared to a forest that has a low demand for
nitrogen. A forest’s need for nitrogen
is strongly dependent upon the age of the forest. Thus, young actively growing forests are far
less likely to experience nitrogen saturation than older stands that have reached the steady-state
equilibrium.

5.6 Conclusions

The main components of fine particulate matter (PM2.5) are soil-related particles, sulfur oxides
(SO2), nitrogen oxides (NOx), and volatile organic compounds (VOC). These components can
combine in a variety of ways that noticeably affect urban, agricultural and natural systems. We
discuss the effects of acid deposition, reduced visibility and ozone in urban environments, on
ag- riculture, and on what we consider to be New Jersey’s most sensitive ecosystems: aquatic
systems and the Pine Barrens. Table 5-1 lists the contribution of the components of fine PM to
these secondary effects. Sulfates and nitrates in the atmosphere nucleate around fine dust
particles or react with other compounds to form secondary fine PM. They can be washed out of
the atmos- phere by rain (wet acid deposition), or directly deposited (dry acid deposition) onto
buildings, trees or whatever else intercepts these particles. Reduced visibility is caused by the
physical scattering of light by PM in the atmosphere. Fine PM scatters light more efficiently
than coarse PM, and is a major cause of the haze that characterizes summertime urban areas and
that reduces visibility at important national monuments like Grand Canyon National Park and
Liberty Island State Park. Ozone is formed as a product of reactions between nitrates and
volatile organic com- pounds, also components of fine PM. To the extent that regulations lower

ambient levels of fine
5-21


PM, they also lower the formation of secondary products and reduce the problems
associated
with acid deposition, reduced visibility and ground-level ozone formation.
Table 5-1: Contributions of PM2.5 particles to environmental effects
Particle type Contributes to
soil reduced visibility
organic carbon compounds ozone
reduced visibility
sulfates acid deposition
reduced visibility
nitrates acid deposition
ozone

Table 5-2 summarizes the major environmental and ecological effects of acid deposition, reduced visibility and ozone, the possible economic ramifications of those effects and the sectors
that would be most likely impacted by changes in ambient fine PM levels. Acid deposition is
the most widespread problem, that affects urban areas as much as natural ecosystems. Its
effects are also among the most well-studied In urban areas acid deposition contributes to
corrosion of building materials, increasing maintenance and repair costs. For instance,
repainting frequency for houses in Virginia increased from once every four years in areas of
low acid deposition to once every one or two years for areas with high acid deposition. Acid
deposition contributes to nitrification and eutrophication of surface waters. High levels of
nitrates in water are toxic to animals and humans, lower levels affect drinking water quality
and can change the dynamics and composition of aquatic plant communities by encouraging
the growth of “weedy” species. Ac- celerated plant growth and death overloads the bottom
communities responsible for decomposi- tion, depletes oxygen levels and can cause deaths that
cascade up the food chain, resulting in the massive fishkills observed in the last two decades

throughout the Northeastern United States. These same conditions cause beach closings and
can be expected to significantly affect recrea- tional activities. Acidic conditions can increase
the concentrations of certain heavy metals such as aluminum, nickel, cadmium and mercury in
runoff which ends up in streams. This can poison fish and shellfish that are important in human
consumption. In terrestrial systems, acid deposi- tion, especially of nitrates, can interrupt
nutrient cycling. It can also increase plant uptake of heavy metals and nitrates, which in turn
increases the morbidity and possibly mortality of ani- mals eating them.

5-22


Table 5-2. Environmental and ecological consequences of acid deposition,
reduced visibility and ozone, and their economic and social ramifications

Problem and scope
Acid deposition
(Urban, widespread)

Economic/social
ramifications

Consequences

Damage to materials

(Freshwater and coastal
waters)

Nitrification and eutrophication of surface waters
Increased runoff of toxic

minerals

(Terrestrial ecosystems)

Changes in nutrient cycling

Reduced visibility
(Local)

Increased maintenance
and repair costs
Increased fishkills

Many or all

Foul odors and unpalatable tastes
in drinking water

Drinking Water

Increased morbidity and mortality
of wildlife and livestock
Loss of ecosystem services,
Loss of sensitive species
like aluminum buffering
from ecosystem
Reduced visibility
Decreased income from tourism
Increased risk of air traffic accidents

Ozone

Reduced visibility

(Local)

Decreased productivity of
plants
Toxicity to animals

Sectors affected

Decreased income from tourism to
parks and reserves
Lowered agricultural productivity
Increased morbidity and
mortality ofeffects
wildlifeon
noticeable

Fisheries

Agriculture
Recreation
Recreation
Industry
Recreation
Agriculture

Reductions in fine PM levels can be expected to have

visibility and
ozone
However, the effects on acid deposition are unclear. Because the causes of acid deposition are
multiple and complex, and because responses and reactions of ecosystems can take years and
decades to register, we do not know what the effects of reducing fine PM will be on levels of
acid deposition, nor what the effects of reducing acid deposition would mean for terrestrial
eco- systems such as the Pine Barrens. For aquatic systems, the reduction of acid deposition is
an im- portant step in reducing the causes of nitrification and eutrophication of surface waters.
How- ever, without concurrent reductions in other sources of nitrates and other pollutants, few
notice- able short-term improvements in aquatic system health would be expected.

5-23


REFERENCES FOR SECTION 5
Anonymous, 1994. Visibility Protection. National Park Service Air Quality Division Visibility Research
Program.
( />Baedecker P. A., E.O. Edney, P. J. Moran, T.C. Simpson & R. S. Williams. 1991. “Effects of acidic deposition on
materials” in Irvine, P. M., ed. Acidic Deposition: State of Science and Technology, Vol. III: Terrestrial,
Materials, Health and Visibility Effects. Washington DC: the US National Acid Precipitation Assessment Program
(State of Science and Technology Report No. 19).
Barton, K. 1958. “The Influence of Dust on Atmospheric Corrosion of Metals”. Werkst. Korros. 8/9:547-549.
Boyd H.P. 1991. A Field Guide to the Pine Barrens of New Jersey. New Jersey: Plexus Publishing, Inc.
Bulgur, A., J. Cosby and R. Webb. 1998. Acid Rain: current and projected status of colwater fish communities in
the Southeastern US in the context of continued acid deposition. June, 1998. For Trout Unlimited.
Butlin, R. N., A. T. Coote, M. Devenish, I. S. Hughes, C. M. Hutchens, J. G. Irwin, G. O. Lloyd, S. W. Massey,
A.
H. Webb, T. J. S. Yates. 1992. “Preliminary Results from the Analysis of Metal Samples from the National
Materi- als Exposure Program (NMEP)” in Atmos. Environ. Part B: 199-206.
Ecological Society of America. 1997. Newsletter. December, 1997. URL: />Environmental Protection Agency (U.S.), 1998. “Environmental Effects of Acid Rain.”

URL:
/>Environmental Protection Agency (U.S.) 1998. "Ozone: Good Up High, Bad Nearby". May 20, 1998.
URL:
/>Environmental Protection Agency (U.S.), 1997a. "PM2.5 Composition and Sources". June 16, 1997.
URL:
/>Environmental Protection Agency (U.S.), 1997b. "Risk Impact Assessment Report for the Particulate Matter
and
Ozone National Ambient Air Quality Standards and Proposed Regional Haze Rule". June 17, 1997.
URL: />Environmental Protection Agency (U.S.) 1997c. "Health and Environmental Effects of Ground-Level Ozone".
July
17, 1997. URL: />Environmental Protection Agency (U.S.) 1997d. “Air Quality Criteria for Particulate Matter”. September 22,
1997.
URL: />Environmental Protection Agency (U.S.). 1985. Developing Long-term Strategies for Regional Haze: Findings
and
Recommendations of the Visibility Task Force. Research Triangle Park, NC.
Environmental Protection Agency (U.S.) 1979. “Protecting visibility: an EPA report to Congress. Research
Triangle
Park, NC: Office of Air Quality and Planning Standards”. EPA Report no. EPA-450/5-79-008. Available from:
NTIS, Springfield, VA; PB80-220320.
Forman T. 1979. The Pine Barrens of New Jersey: An Ecological Mosaic. In: Pine Barrens. Ecosystems and Landscape. Ed. Forman T.T. New York: Academic Press.
Graedel, T. E., K. Nassau and J. P. Franey. 1987. “Copper patinas formed in the atmosphere—I. Introduction”.
Cor- ros. Sci. 27: 639-657.

5-24


Husar, R., J Husar and S. Falke. 1995. Fine Particle Maps Derived from Regional PM2.5 and Visibility Data. Center
for Air Pollution Impact and Trend Analysis (CAPITA)
Levy, M. A. 1993. European Acid Rain: The Power of Tote-Board Diplomacy. In: Institution for the Earth. Eds:
Haas P.M., Keohane R.O. & Levy M.A. Massachusetts: The MIT Press.

Kane, P.F., Rosselet D.A. & Anderson K. 1992. New Jersey Audubon Society’s Bridges to the Natural World. New
Jersey: New Jersey Audubon Society.
Martinez-Ramirez, S. and G. E. Thompson. 1998. “Dry and Wet ‘Deposition’ Studies of the Degradation of Cement
Mortars”. Mater. Construc. 48: 15-31.
Morgan M. 1984: “Acidification of Headwater Streams in New Jersey Pinelands: A re-evaluation.” Limnol.
Oceanogr., 29, 1259-66.
National Acid Precipitation Assessment Project. 1998. NAPAP Biennial Report to Congress: an integrated assessment. May, 1998. Silver Springs, MD. URL: />National Park Service. 1998. "Air Quality and Deposition Monitoring". URL:
/>National Research Council. 1979. Airborne Particles. Baltimore, MD: University Park Press.
Robichaud B. and Buell M.F. 1973. Vegetation of New Jersey. New Jersey: Rutgers University Press.
Ross, D. 1988. “Effects of Visual Air Quality on Visitor Experience.” Chapter 3 in Air Quality in National Parks: A
Summary of Findings from the National Park Service Air Quality Research and Monitoring Program. Natural Resources Report 88-1. URL: />Spence, J. W., F. H. Haynie and J. B. Upham. 1975. “Effects of Gaseous Pollutants on Paints: A Chamber Study”.
J.
Paint Technology 47: 57-63.
Tolley, G. A., A. Randall, G. Blumquist, R. Fabian, G. Fishelson, A. Frankel, J. Hoehn, R. Krumm, E. Mensah
and
T. Smith. 1986. Establishing and Valuing the Effects of Improved Visibility in the Eastern United States.
Washing- ton, D. C.: U.S. Environmental Protection Agency.
Trijonis, J. C., W. C. Malm, M. Pitchford and W. H. White. 1991. “Visibility: Existing and Historical Conditions
—
Causes and Effects” in Irving, P. M., ed. Acidic Deposition: State of Science and Technology, Volume III:
Terres- trial, Materials, Health and Visibility Effects. Washington, D. C.: The US National Precipitation
Assessment Pro- gram. (State of Science and Technology Report no.24)
Turner, R. S., R. J. Olson and C.C. Brant. 1986. “Areas having Soil Charateristics that may indicate Sensitivity to
Acidic Deposition under alternative Forest Damage Hypotheses”. ORNL/TM-9917. Oak Ridge National
Laboratory, Oak Ridge, TN.
Van der Straaten, J. 1998. “Is Economic Value the Same as Ecological Value?” VII International Congress of
Ecology INTECOL, Firenze. July 19-25, 1998.
Van Sickle, J., and M. R. Church. 1995. “Methods for Estimating the Relative Effects of Sulfur and Nitrogen
Deposition on Surface Water Chemistry.” U.S. Environmental Protection Agency, Washington, D. C. EPA/600/RWernstahl, K. M. 1998.” Design and Evaluation of Accelerated Tests for the Prediction of the Services Life of
95/172.

Automotive Coatings”. Jocca-surf Coat. Int. 80: 560.
Whitby, K. T., R. B. Husar and B. Y. H. Liu. 1972. “The Aerosol Size Distribution of Los Angeles Smog.” J. Colloid Interface Sci. 39: 177-204.

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