EPA's 2007 Report on the Environment:
Highlights of National Trends
Peer Review and Public Comment Draft
August 2007
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not
been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy. Please
submit comments at www.regulations.gov.
-------
EPA's 2007 REPORT ON THE ENVIRONMENT:
HIGHLIGHTS OF NATIONAL TRENDS
The U.S. Environmental Protection
Agency (EPA) developed EPA's
2007 Report on the Environment
to help answer questions that are
of critical importance to the
Agency's mission to protect human
health and the environment. The
Report on the Environment docu-
ments trends in the condition of
the nation's environment and
human health and identifies signif-
icant gaps in our knowledge. It is
not intended to be a report card
on EPA's programs and activities.
CONTENTS
About This Document 2
Air 4
Outdoor Air 5
Acid Rain and Regional Haze 6
Ozone Depletion 7
Greenhouse Cases 8
Indoor Air 9
Water 10
Fresh Surface Waters 11
Ground Water 12
Wetlands 13
Coastal Waters 14
Drinking Water 15
Recreational Waters 16
Consumable Fish and Shellfish 17
Land 18
Land Cover 19
Land Use 20
Wastes and the Environment 21
Chemicals Applied and Released to Land .22
Contaminated Land 23
Human Health 24
Health Status 25
Diseases and Health Conditions 26
Exposure to Environmental Contaminants 27
Ecological Condition 28
Patterns in Ecological Systems 29
Biological Diversity 30
Ecological Processes 31
Physical and Chemical Attributes
of Ecological Systems 32
Ecological Exposure to Contaminants .. .33
Conclusion 34
List of Indicators . . .35
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not
been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy. Please sub-
mit comments at www.regulations.gov.
-------
ABOUT THIS DOCUMENT
Written for a general audience, this document, EPA's 2007 Report on the
Environment: Highlights of National Trends, summarizes some of the more
important findings from a more comprehensive companion report, EPA's
2007 Report on the Environment: Science Report. A Web-based tool, the elec-
tronic Report on the Environment (e-ROE), facilitates navigation and search-
ing across both documents.
Highlights of National Trends is organized around 25 topics that are impor-
tant to EPA. Each topic page includes a brief summary of what we know—
and don't know—about conditions and trends in the nation's air, water,
land, ecological condition, and human health. The information on these
topics comes from highly reliable indicators (see box) and is based on the
most recent data available from a variety of governmental and non-govern-
mental organizations.
Highlights of National Trends features a subset of indicators from the more com-
prehensive Science Report, The indicators shown here were selected for inclu-
sion based on their importance to the public and scientists, as well as their
ability to answer a series of key questions about the environment. These key
questions and 86 associated indicators form the framework of the Science
Report and are listed at the end of Highlights of National Trends. In addition,
only a few of the most important data gaps and limitations from the Science
Report are included in this report. The reader is encouraged to consult the
Science Report and e-ROE for more information.
ENVIRONMENTAL INDICATORS
The indicators used in the Report on the Environment:
• Rely on actual measurements of environmental and human health
conditions over time.
• Meet a set of standards, which include quality, accuracy, relevance,
and comparability.
• Were reviewed by an independent scientific panel to ensure that they
meet these standards.
• Are national (or in some cases regional) in coverage. They do not
describe trends or conditions of a specific locale.
• Come from many governmental and non-governmental organizations,
which collect data at different time periods and for varying purposes.
• Can only partially answer the key questions.
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has
not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Please submit comments at www.regulations.gov.
Introduction 2
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ABOUT THE DATA
IN THE REPORT ON
THE ENVIRONMENT
The indicators in the Report on the Environment are comprised of actual meas-
urements of the environment over time and do not describe activities to pro-
tect the environment. All of the indicators were reviewed by an independent
panel and meet strict definitions and criteria, including scientific quality and
national (or in some cases regional) coverage. Other sources of information are
not included in this report because they do meet one or more of the criteria.
Data limitations are noted to provide the reader with information about the qual-
ity or extent of the data presented that may affect the way in which they are
used. Generally, such limitations cause greater uncertainty in drawing conclusions
about actual conditions in the environment. Data gaps are noted to identify areas
or aspects of the environment in which little or no measurement is done. This
report does not propose actions to reduce data limitations or fill gaps.
As such, each topic page in Highlights of National Trends acknowledges some of
the most important limitations of the indicators presented, or where gaps exist.
For example, we do not have long-term trends about the condition of the
nation's waterways because of inconsistent measurements over time.
ERA'S 2007
REPORT ON THE
ENVIRONMENT
Highlights of National Trends is one of three products that collectively make up
EPA's 2007 Report on the Environment. The other two products are:
• EPA's 2007 Report on the Environment: Science Report is the source of the
information presented in Highlights of National Trends. The Science Report
is organized around key questions about the environment and presents
86 indicators to help answer those questions.
• The electronic Report on the Environment (e-ROE) is a Web-based tool for
navigating and searching EPA's 2007 Report on the Environment: Science
Report and EPA's 2007 Report on the Environment: Highlights of National
Trends (insert URL to be provided when available).
UPDATES TO THE
REPORT ON THE
ENVIRONMENT
EPA's 2007 Report on the Environment brings together the most consistent
and reliable information on national environmental conditions and trends
currently available under a single cover. It builds on EPA's Draft Report on the
Environment 2003, which was the Agency's first effort to assemble scientifi-
cally sound indicators on the status and trends of the nation's environment.
Since the release of the 2003 report, EPA has revised, updated, and refined
the information in the Report on the Environment in response to scientific
developments as well as stakeholder feedback. EPA will publish periodic
updates of the Report on the Environment and use it to inform the Agency's
strategic planning process.
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has
not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Please submit comments at www.regulations.gov.
Introduction
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Outdoor Air
Acid Rain and Regional Haze
Ozone Depletion
Greenhouse Gases
Indoor Air
oxygen and carbon dioxide needed to sus-
lain human, animal, and plant life. Higher
up, a natural layer of ozone shields life on Earth
from the sun's harmful rays, and at all levels of the
atmosphere, naturally occurring greenhouse gases
help maintain a climate suitable for life. Indoors
and outdoors, from ground level to high above the
planet's surface, the condition of the air is critical to
human health and the environment.
Tracking the nation's air quality is challenging
because of the many sources, types, and effects of
air pollution. Most outdoor air pollution can be
directly traced back to emissions sources that
release pollutants into the air. Others, such as
ozone, are formed when an emission reacts with
other substances in the air to form a pollutant.
Once airborne, pollutants can be transported
long distances by wind or transformed into other
compounds. They also can fall back to Earth, con-
taminating water and land. Both the amount of
pollutants emitted into the air and how these
pollutants move through the atmosphere deter-
mine air pollution levels, which are measured as
concentrations.
Many indicators are needed to characterize out-
door air quality separate from indoor air quality,
to characterize air quality trends at ground level
as well as higher in the atmosphere, and to char-
acterize both emissions and concentrations. Also,
air quality varies considerably with location and
time, which makes it challenging to obtain a
representative national picture.
This DRAFT is intended for public comment\
and peer review. Please submit comments
at www.regulations.gov.
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OUTDOOR AIR
Outdoor air pollutants come
from human activities such as
electricity production, industrial
processes, and transportation,
and from natural sources like wildfires and wind-blown
dust. Some of these pollutants can harm human health,
the environment, and other valued resources.
Beginning in the 1970s, EPA developed standards to
protect human health and the environment from six
common air pollutants that pose serious health and
environmental effects: carbon monoxide, lead, nitrogen
dioxide, ozone, particulate matter, and sulfur dioxide.
These pollutants are often referred to as "criteria pollutants."
KEY POINTS
Nationwide, emissions of criteria pollutants (or the
pollutants that form them) due to human activities
have decreased. Between 1990 and 2002, emissions of
carbon monoxide, volatile organic compounds (which
lead to the formation of ozone), particulate matter,
sulfur dioxide, and nitrogen oxides (which lead to the
formation of ozone and particulate matter) decreased by
differing amounts, ranging from 18 to 34 percent. For
lead, emissions have decreased by 99 percent, but this
reduction is based on data that span a longer time
frame (1970 to 2002).
Outdoor air concentrations of carbon monoxide,
lead, nitrogen dioxide, ozone, and particulate
matter have decreased over the decades during
which the current nationwide monitoring net-
work has operated. These reductions are consistent
with the observed decreases in emissions mentioned
above. In most or all of the United States, concentra-
tions of carbon monoxide, lead, and nitrogen diox-
ide have decreased such that levels now meet EPA's
standards to protect health and the environment.
Though concentrations of ozone (see graphic) and
particulate matter have decreased nationwide, con-
centrations still exceed EPA's standards for either or
both pollutants in dozens of metropolitan areas.
Subsequently, EPA identified an additional 188 pollutants
of concern, called air toxics, which are known or suspect-
ed to cause cancer, other serious health problems, and
adverse environmental effects. Examples include benzene,
which is found in gasoline; metals such as mercury and
cadmium; dioxin; and asbestos.
There are several ways to measure outdoor air pollution
trends. Emissions can be measured or estimated at their
source, and concentrations of pollutants in air can be moni-
tored at numerous outdoor locations around the country.
National indicators are not available for other
aspects of outdoor air quality. While indicators pro-
vide insights on emissions and concentration trends
for many pollutants, monitoring networks are not yet
extensive enough to determine national trends in
concentrations for all pollutants, including many air
toxics. Further, the indicators are limited in quantifying
how outdoor air quality affects human health and the
environment. Although strong evidence links outdoor
air pollution to health effects at specific locations, few
long-term studies at a national scale have measured
the extent to which health effects are linked directly to
outdoor air quality.
Ozone Concentrations in Outdoor Air,
1980-2004
\
Concentrations are expressed in terms of EPA's air quality standard.
Source: U.S. Environmental Protection Agency. Air Quality System
Database. 2005
For selected air toxics, emissions due to human
activities and concentrations have decreased.
Nationwide, emissions summed across all 188 air toxics
decreased between 1990 and 2002. This includes a
54-percent reduction in mercury emissions. Monitoring
networks are extensive enough to determine corre-
sponding national trends in outdoor air concentrations
of benzene, which decreased 61 percent between
1994 and 2004.
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Chapter 1 Air 5 Outdoor Air
0.14
90% ol sites have concentrations below this line
T
Average
10% ot sites have
concentrations
below this line
' EPA's air quality
standard
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ACID RAIN AND REGIONAL HAZE
Each year in the United States,
millions of tons of sulfur dioxide
and nitrogen oxides are released
into the air from the burning of
fossil fuels. These pollutants react with other airborne
substances to form acidic compounds (sulfates and
nitrates). Acid deposition occurs when these compounds
fall to the Earth in one of two forms: wet (dissolved in
rain, snow, and fog) or dry (as gases or particles). Wet
deposition is more commonly referred to as "acid rain."
Acid deposition is of concern because it can make soils,
lakes, and streams more acidic, which can harm fish,
amphibians, water birds, and other species in affected
areas. It can also damage trees, buildings, monuments,
KEY POINTS
painted surfaces, and other materials. Acid rain can be
tracked in several ways: by evaluating emissions of sulfur
dioxide and nitrogen oxides (the pollutants that form
sulfates and nitrates), by monitoring acid rain directly,
and by measuring the acidity of water bodies.
The pollutants that form acid rain also form airborne par-
ticulate matter, which contributes to regional haze.
Regional haze, tracked by visibility measurements, is
caused when sunlight encounters tiny airborne particles
that limit the distance one can see. Regional haze also
degrades the color, clarity, and contrast of vistas, includ-
ing those found in many National Parks and Wilderness
Areas. Certain substances impair visibility more during
humid conditions.
Nationwide, emissions of the main pollutants that
form acid rain decreased between 1990 and 2002.
Emissions of sulfur dioxide due to human activities
decreased by 34 percent, and emissions of nitrogen
oxides due to human activities declined by 18 percent.
Acid rain, as measured by wet deposition of sul-
fates and nitrates, decreased across most of the
country from 1989 to 2004. Consistent with emis-
sions data, average regional decreases in wet deposi-
tion of sulfate during this time were 36 percent in the
Northeast, 32 percent in the Midwest, 24 percent in
the mid-Atlantic, and 19 percent in the Southeast (see
graphic). Wet deposition of nitrate also decreased in
some parts of the country, but to a lesser extent than
wet deposition of sulfate.
Many surface waters in the upper Midwest,
Adirondack Mountains, and northern Appalachian
regions have become less acidic since 1990. This
change corresponds to a decrease in acid rain in these
regions. While acidic surface waters are still found in
these areas, some surface waters are showing signs of
recovery. National indicators are not available to track
trends in other ways that acid rain has harmed the
environment or human health.
Regional haze in National Parks and Wilderness
Areas remained relatively unchanged between
1992 and 2001. On average, the West has substan-
tially better visibility than the East due to regional dif-
ferences in air pollution and the greater humidity in
the East. National indicators are not available to track
regional haze in cities or other populated areas.
Wet Sulfate Deposition, 1989-1991 Versus 2002-2004
1989-1991
2002-2004
Source: National Atmospheric Deposition Program. 2005
Wet sulfate deposition (kilograms per hectare):
0 5 10 15 20 25 30 35 >40
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Chapter 1 Air 6 Acid Rain and Regional Haze
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OZONE DEPLETION
Ozone is a gas present through-
out the Earth's atmosphere. Most
of this ozone is concentrated in a
layer in the stratosphere—a por-
tion of the atmosphere many miles above the planet's sur-
face. The ozone layer protects people, animals, plants, and
other living things by absorbing most of the sun's harmful
ultraviolet radiation, which can lead to more cases of cer-
tain types of skin cancer and cataracts and can harm crops
and ecosystems. In contrast, ozone in the troposphere (the
portion of the atmosphere from ground-level to the strato-
sphere) is a pollutant that poses a health risk.
Certain ozone-depleting substances, which are man-made
and emitted at ground level by sources worldwide, have
been damaging the ozone layer for many years. Once
these chemicals rise from the troposphere into the
stratosphere, they directly lead to ozone depletion: a thin-
ning of the ozone layer over some areas of the world.
Ozone-depleting substances include chlorofluorocarbons
(CFCs), which were once extensively used as propellants
KEY POINTS
in spray cans and as refrigerants and solvents. Many coun-
tries, including the United States, are phasing out the pro-
duction and use of CFCs and other ozone-depleting
substances. Because many of these substances persist in
air for a very long time, the ozone layer will take years to
recover, even after these chemicals are no longer released.
Ground-based measurement networks and instruments
on board aircraft, balloons, and satellites are used to
monitor both the thickness of the ozone layer and con-
centrations of ozone-depleting substances in the tropo-
sphere and in the stratosphere.
Stratospheric ozone over North America has
decreased since 1979. Before the late 1970s, there
was little change, beyond natural variations, in the
thickness of the ozone layer over North America.
Since then, the thickness of the ozone layer has
decreased, reaching its lowest level in 1993 (see
graphic), with no further decline occurring in more
recent years. The ozone layer has since begun to v
recover, but overall levels during 1998 to 2001 were ^v
still 3 percent lower, on average, than those observed
20 years earlier.
Tropospheric concentrations of total ozone-
depleting substances have been slowly declining.
Since 1994, total ozone-depleting substances in the
troposphere have declined 11 percent, and this
decline has contributed to the recent recovery in
stratospheric ozone levels. The trends for individual
ozone-depleting substances vary. Tropospheric con-
centrations of many ozone-depleting substances
have declined since 1994, but concentrations of
halons (fire extinguishing agents) and hydrochloro-
fluorocarbons (HCFCs), a class of chemicals being
used to replace CFCs, increased.
Total Ozone Levels Over North
America, 1965-2005
•i 2-
0-
*- -2
"*
-
1965 1970 1975 1980 1985 1990 1995 2000 2005
Total ozone refers to the total
ozone concentration in a col-
umn of air between the Earth's
surface and the top of the
atmosphere.
Source: 1965-2003 data from
World Meteorological
Organization et a/.. 2003, and
2004-2005 data from unpublished results provided by World
Meteorological Organization
—-
Ground-based data
Data collected by
multiple satellites
and reported in four
different studies
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Chapter 1 Air 7 Ozone Depletion
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GREENHOUSE GASES
Some gases in the atmosphere
trap part of the Earth's outgoing
energy, which causes the atmos-
phere to retain heat and affect
climate. These gases are called greenhouse gases, and
they include carbon dioxide, methane, nitrous oxide, and
certain man-made chemicals. Some greenhouse gases
occur naturally, while emissions due to human activities,
such as electricity production and transportation, add to
the natural concentrations in the atmosphere.
Greenhouse gases are important to track because
increased concentrations cause the atmosphere to retain
heat which, in turn, can affect various aspects of climate,
KEY POINTS
Concentrations of several important greenhouse
gases have risen substantially over the past 100
years and are currently higher than at any time in
the past 400,000 years. Cases trapped in ice over
the past 400,000 years confirm that present concen-
trations of carbon dioxide (see graphic), methane,
nitrous oxide, and certain synthetic chemicals are
unprecedented in this period, even after accounting
for natural fluctuations.
such as temperature, evaporation, and precipitation.
Natural phenomena, like volcanic activity and variations
in the sun's output, and other human activities, such as
land use changes, also affect climate. Human health,
agriculture, water resources, forests, wildlife, and coastal
areas all can be affected by climate change.
National trends in greenhouse
gases are characterized by
tracking emissions of these
gases from human activi-
ties and concentrations of
these gases in the air.
Between 1990 and 2003, U.S. greenhouse gas
emissions from human activities rose 13 percent;
the primary source of these emissions was fossil
fuel combustion. Carbon dioxide makes up most of
this increase. Energy use, primarily electricity genera-
tion and transportation, accounted for approximately
85 percent of the emissions in 2003.
While trends in emissions and concentrations of
greenhouse gases are based on robust data, gaps
remain. For both emissions and concentrations, trends
have been quantified for several of the most important
greenhouse gases, but not for every greenhouse gas.
i
Global Atmospheric Concentrations of Carbon Dioxide (CO2) Over Geological Time and in Recent Years
400 •
300'
250'
200
ISO
100
50
0
415.155BCto337BC
8947 BC10 1975 AD
1959 AD 10 2004 AD
•S>v
The concentration data shown are reported in multiple scientitic publications. Complete citations for these peer-reviewed publications are provided in
the Report on the Environment: Science Report
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Chapter 1 Air 8 Greenhouse Cases
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INDOOR AIR
Many substances affect the qual-
ity of air inside homes, schools,
workplaces, and other buildings.
Some of these contaminants
come from outdoor air and building materials; others are
produced by indoor activities such as cooking, smoking,
and using cleaning materials. Natural substances, such as
molds, can also affect indoor air quality.
Indoor air quality is important because Americans, on
average, spend most of their time indoors. In addition,
the indoor concentrations of some pollutants can exceed
levels typically found outdoors. Health effects associated
with indoor air pollutants include irritation of the eyes,
nose, and throat; headaches, dizziness, and fatigue;
respiratory diseases; heart disease; and cancer.
National indicators are available for two harmful sub-
stances found in indoor air: radon and environmental
tobacco smoke. Radon is a naturally occurring radioac-
tive gas found underground. It can seep into buildings
through cracks in floors and walls, and is a risk factor for
lung cancer. For homes with radon levels above EPA's
radon action level, EPA recommends that occupants take
action to protect their health—for example, by installing
a mitigation system to reduce radon levels.
Environmental tobacco smoke is associated with numer-
ous health effects, including coughing, heart disease,
and lung cancer. Children are at particular risk from
exposure to environmental tobacco smoke because they
are still developing physically.
KEY POINTS
Between 1990 and 2004, both the number of
homes with radon mitigation systems and the num-
ber of homes needing mitigation increased. Homes
with mitigation systems rose from 155,000 to 577,000,
and homes needing mitigation increased from 5 mil-
lion to 6.3 million due to an increase in housing stock
(see graphic). Thus, more than 90 percent of the
nation's homes that exceed EPA's radon action level
do not have mitigation systems, though some of N.
these homes have been built with new, radon-resist- >
ant construction features to reduce radon exposures.
Over the past decade, exposure to environmental
tobacco smoke among nonsmokers decreased con-
siderably. All population groups, regardless of age, sex,
or ethnicity, experienced this decrease, which was likely
due to behavior changes such as reduced smoking and
smoking restrictions in some public places. Exposure to
environmental tobacco smoke is measured by blood
levels of cotinine, a substance produced in the body
when a person is exposed to nicotine. Among non-
smokers, children, on average, have more than twice
the level of blood cotinine as adults.
National indicators currently are not available for
a broader range of pollutants and substances
found in indoor air. Scientists have studied numer-
ous other indoor air quality issues, but the available
information does not track trends over time or across
the entire nation.
Radon in U.S. Homes, 1990-2004
-
-
3H
-
Homes above EPA's radon action level
Homes with radon mitigation systems
o-
1990 1992 1994 1996 1998 2000 2002 2004 2006
Source: U.S. Environmental Protection Agency, "National Radon
Residential Survey: Summary Report." 1992, updated with 2000 U.S.
Census data, and U.S. Environmental Protection Agency, unpublished
industry data on mitigation system sales. 2005
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Chapter 1 Air 9 Indoor Air
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WATER
Fresh Surface Waters
Ground Water
Wetlands
Coastal Waters
Drinking Water
Recreational Waters
Consumable Fish and
Shellfish
—water underground, the nation's water
resources are integral to life. Water resources
encompass water bodies (such as coastal waters,
lakes, streams, ground water, and wetlands) and
their associated ecosystems. They sustain a multi-
tude of plant and animal species and provide for
drinking water, irrigation, fishing, recreation, and
many other needs.
The ability of water resources to support these
functions depends on their extent and condition.
The extent of a water resource refers to its depth,
flow, volume, and area. Condition reflects the abili-
ty of a water resource to sustain ecological needs
and human uses. The extent and condition of
water resources can affect the health and well-
being of people, ecosystems, and critical environ-
mental processes.
In addition, because water is constantly cycling
above and below the surface of the Earth, there are
many connections between water resources and
other parts of the environment. For example, fertil-
izers and pesticides used on land can leach into
underground or surface water supplies. Also, emis-
sions released into the air can be deposited, via
rain or snow, into a lake or stream.
A variety of methods are used to collect data on
water resources, including targeted monitoring of
specific water resources and select sampling of
locations deemed to be representative of a larger
area. One of the challenges in assessing the extent
and condition of water resources is that a single
data collection method is rarely perfect for every
situation. This chapter provides an overview of
national-level trends where nationally consistent
data are available, but does not describe the extent
or condition of local water bodies or the full range
of variations and extremes that occur within
individual water bodies.
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Chapter 2: Water
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FRESH SURFACE WATERS
Lakes, ponds, rivers, and streams
sustain ecological systems and
provide habitat for many plants
and animals. They provide
drinking water for people and support agriculture, indus-
try, hydropower, recreation, and other uses. Both natural
processes and human activities influence the condition
of these waters. For example, discharges of industrial
contaminants, agricultural and stormwater runoff, air
pollutants deposited into water, and invasive species
can all affect water bodies.
A variety of biological, physical, and chemical characteris-
tics are used to assess the condition of fresh surface
waters. An important biological characteristic is the pres-
ence and diversity of bottom-dwelling (benthic) macroin-
vertebrate communities, such as insect larvae, mollusks,
and worms. Some species of macroinvertebrates are
sensitive to disturbances in their habitat, such as pollu-
tion, while others are tolerant of disturbances.
Examples of physical characteristics are depth and flow.
Major changes in stream flows can affect plant and animal
species that have adapted to particular seasonal fluctua-
tions in flow, such as those that require a period of low or
no stream flow in their habitat at a certain time of year.
Key chemical characteristics include acidity and dissolved
oxygen. Acidity in soils, lakes, and streams can harm
aquatic species and ecosystems. Low dissolved oxygen
content can also be harmful. Excess concentrations of
the nutrients nitrogen and phosphorous (from sewage
or agricultural runoff, for instance) can cause algae to
bloom in water, blocking sunlight and depleting the
oxygen needed by fish and other organisms.
KEY POINTS
In about 42 percent of wadeable stream miles,
benthic macroinvertebrate communities showed
substantial disturbances; about 28 percent
showed little disturbance (see graphic). Low biologi-
cal diversity potentially indicates significant pollution
and higher disturbance. By contrast, communities that
are biologically diverse and include many pollution-
sensitive species likely indicate that a stream is less v
disturbed. Wadeabale streams are streams and rivers >^
shallow enough to sample with boats.
More than 60 percent of streams and rivers
measured in the 1990s showed major changes in
the volume or timing of their high or low flows
compared to a baseline period from 1930 to
1949. Also, the percentage of streams in largely arid
grasslands and shrublands with no-flow periods
decreased from 24 percent in the 1950s to 14 per-
cent in the 1990s.
Fresh surface waters show a mixed picture of
chemical condition. Acidity decreased in lakes and
streams in some regions sensitive to acid rain; others
showed little change. Approximately 30 percent of
the nation's wadeable stream miles contained high
nitrogen and phosphorus concentrations. Nitrate dis-
charges increased in the Mississippi River. Phosphorus
discharges decreased in the St. Lawrence and
Susquehanna Rivers, but showed no change in trend
in the Mississippi or Columbia Rivers.
National indicators are not available for many
key stressors or for the extent of surface waters.
Key stressors include pollution from various sources
and toxic contaminants in sediments, which can
impact water quality and potentially enter the
aquatic food web.
Benthic Community Condition in Wadeable Streams,
2000-2004
Not assessed/no data
, Least
disturbed
Most
disturbed
Moderately
disturbed
Data gathered from 2000 to 2004 in the lower 48 states.
Categories based on the number and diversity ot benthic species pres-
ent, with "least disturbed" being the most diverse. Graphic shows the
percent of stream miles in each category.
Source: U.S. Environmental Protection Agency, "Wadeable Streams
Assessment." 2006
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Chapter 2 Water 11 Fresh Surface Waters
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GROUND WATER
More than 1 million cubic miles
of fresh water lies underground,
stored in cracks and pores below
the Earth's surface. The vast
majority of fresh water available for human use is ground
water, which has 30 times the volume of the world's
fresh surface waters. Many parts of the country rely heav-
ily on ground water for important needs such as drink-
ing water, irrigation, industry, and livestock.
Some ecological systems also depend upon ground
water. For example, many fish species depend on spring-
fed waters for their habitat or spawning grounds.
Springs occur when a body of ground water reaches the
Earth's surface. By some estimates, ground water feeds
about 40 percent of total national stream flow, and the
percentage could be much higher in arid areas.
Human activities and natural factors can affect both the
extent and condition of ground water. Pesticides, fertiliz-
ers, and wastes, as well as natural substances like arsenic,
can contaminate ground water. For example, fertilizers
and animal wastes can release nutrients such as nitrate.
Withdrawing too much ground water from a source can
reduce the water depth in streams and lakes, affecting
vegetation and wildlife habitat. It can also cause land to
subside and sinkholes to form. Once depleted, some deep
aquifers (underground geological formations containing
water) can take thousands of years to recharge, affecting
the supply of ground water available for future needs.
KEY POINTS
About 61 percent of shallow wells tested in agri-
cultural areas contained pesticide compounds.
For 47 of the 83 pesticides for which standards or
guidelines exist, fewer than 1 percent of these wells had
concentrations of pesticides above the human health
benchmark.
In about 21 percent of shallow wells, average
nitrate concentrations exceeded the federal
drinking water standard and were significantly
higher than the levels generally found in areas
with little human influence (see graphic). Public
water systems must test for nitrate and treat the
water if levels exceed federal health-based
standards.
The data in this report do not provide information
about the condition of deeper aquifers, which are
more likely to be used for public water supplies.
These data only characterize the uppermost layers of
shallow aquifers typically used by private wells. There
are no national treatment or monitoring requirements
for private wells; however, owners should test their
water periodically to identify possible health risks.
There are no consistent national indicators for
many aspects of ground water condition or
extent. These aspects include the presence of
chemicals other than nitrates and pesticides in
agricultural areas and the condition of ground water
in predominantly non-agricultural areas, including
urban areas. Localized events, such as chemical spills
or leaks from underground storage tanks, can affect
ground water in urban areas; such events are not
easily captured in measures at the national level.
Nitrate Concentrations in Shallow Ground Water
in Agricultural Watersheds, 1992-2001
10mg/L
or more
<2 mg/L
42.2%
Data gathered in a survey of 1.423 wells in the lower 48 states from
1992 to 2001. Graphic shows percent of wells in each category.
The federal drinking water standard for nitrate is 10 milligrams of
nitrate per liter of water (10 mg/L).
Source: U.S. Geological Survey, National Water Quality Assessment
Program, 2006
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Chapter 2 Water 12 Cround Water
-------
WETLANDS
Wetlands—areas that are period-
ically saturated or covered by
water—are an important ecolog-
ical resource. Wetlands are like
sponges, with a natural ability to store water. They act as
buffers to flooding and erosion, and they improve the
quality of water by filtering out contaminants. Wetlands
also provide food and habitat for many plants and ani-
mals, including rare and endangered species. In addi-
tion, they support activities such as commercial fishing
and recreation.
Both losses and gains can occur in wetlands extent.
Natural forces and human activities (such as hurricanes,
sea level change, and certain agricultural and forestry
practices) can affect wetlands through increased erosion
and sedimentation. Draining or filling wetlands for agri-
culture or other development is the main cause of wet-
lands loss. Cains can occur when wetlands are created
or restored.
Changes in the extent or type of wetlands can have
major ecological impacts. For example, the conversion of
a forested wetland to one with
scrub and oak trees can
change habitat types and
alter the structure of
plant and animal com-
munities present.
Such a conversion
can occur through
natural changes in
plant communities or
by clearing trees from a
forested wetland.
KEY POINTS
The overall extent of wetlands in the lower 48
states declined over the past 50 years. The rate of
loss has slowed over time, however, and the most
recent data show a net gain in wetlands acreage
nationwide (see graphic). Gains and losses vary
significantly by wetland type. >^
These data do not evaluate wetland quality or
condition. Wetland condition is difficult to charac-
terize fully, and there is no national indicator to
measure it directly. This is partly because each wet-
land has unique characteristics, such as the move-
ment and abundance of water, the minerals in the
underlying soil, and the combinations of plant and
animal species present.
National data do not capture locations or patterns
of wetland change. Both are important for under-
standing condition—for example, whether large wet-
lands are being left intact, or are being fragmented
into smaller pieces that are less connected, and there-
fore less able to perform their ecological functions.
Average Annual Change in Wetland Acreage,
1954-2004
100.000
-
-100.000
-200.000-
-300.000
-400.000
-500.000
t32.000
-58.600
-290,000
-458.000
1954-1974 1974-1983 1986-1997 1998-2004
Data gathered in the lower 48 states.
Source: Dahl. IE.. "Status and Trends of Wetlands in the Conterminous
United States 1998 to 2004." 2006
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Chapter 2 Water 13 Wetlands
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COASTAL WATERS
Coastal waters—the interface
between terrestrial environments
and the open ocean—encom-
pass many unique habitats such
as estuaries, coastal wetlands, seagrass meadows, coral
reefs, and mangrove and kelp forests. These ecologically
rich areas support waterfowl, fish, marine mammals, and
many other organisms.
Human activities and natural factors can affect the condi-
tion of coastal waters. Sewage overflow, agricultural
runoff, storms, erosion, and sedimentation can all
increase the amount of nutrients (such as nitrogen and
phosphorus) and pathogens (disease-causing organisms)
in coastal waters. Chemical contamination from industri-
al activities, electricity generation, and other sources are
also concerns, as are invasive species and overharvesting
of fish and other marine species.
Organisms that live in and on the ocean floor (benthic
organisms) are a key measure of coastal water condition
KEY POINTS
Coastal benthic communities in 70 percent of the
areas sampled showed little evidence of distur-
bance (see graphic). The benthic communities in these
areas showed high biological diversity and the presence
of pollution-sensitive species, likely indicating that the
waters were relatively unpolluted.
In the Chesapeake Bay, submerged aquatic
vegetation (SAV) increased from 41,000 to
78,000 acres from 1978 to 2005. However,
current acreage is still less than half of the
historical coverage (from the mid-1930s).
The extent of these plants is ecologically significant
because the vegetation provides food and habitat for
many organisms, adds oxygen to the water, filters
sediments, inhibits wave action that erodes shore-
lines, and absorbs excess nutrients.
Elevated levels of nutrients and chlorophyll-o are
present in slightly less than 10 percent of the
nation's coastal waters. However, in areas such
as the Gulf of Mexico "dead zone" and Long Island
Sound, substantial areas of hypoxia (when dissolved
oxygen is below levels necessary to sustain most
animal life) remain.
because these organisms are sensitive to pollution. One
important group of benthic organisms, known as
benthic macroinvertebrates, includes worms, clams,
crabs, and lobsters.
Scientists monitor several interlinked characteristics of
water quality in coastal areas: nutrients, chlorophyll-o,
dissolved oxygen, and water clarity. Plants need nutrients
to grow, but in excess, nutrients fuel the growth of
algae. High levels of chlorophyll-o indicate overproduc-
tion of algae. Too much algae leads to low levels of dis-
solved oxygen in the water and decreased water clarity.
The resulting lack of oxygen and sunlight can harm
plant and animal life.
Scientists also monitor plants that grow under water in
coastal areas, known as submerged aquatic vegetation
(SAV). Like all plants, SAV needs sunlight to grow and
survive. Its growth can be affected by excess nutrients,
as well as suspended sediments (loose particles of clay
and silt in the water), which can block sunlight from
reaching the plants.
There are no national indicators for the extent of
coastal waters (except for coastal wetlands) and
many aspects of their condition. For example, there
are no indicators for invasive species, condition of coral
reefs, or status of coastal fish and shellfish communities.
Benthic Community Condition in Estuarine Waters,
1997-2000
Most
disturbed
Least
disturbed
Moderately
disturbed
Data gathered in the lower 48 states and Puerto Rico from 1997 to 2000.
Categories based on the number and diversity of benthic species present,
with "least disturbed" being the most diverse. Graphic shows the percent
of estuarine area in each category. Estuarine areas are where the sea
meets a freshwater stream or river.
Source: U.S. Environmental Protection Agency. "National Coastal
Condition Report II." 2004
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14
Chapter 2 Water
Coastal Waters
-------
DRINKING WATER
Virtually all drinking water in the
United States comes from fresh
surface water and ground water.
These source waters can contain
industrial, domestic, and agricultural contaminants, as well
as naturally occurring contaminants such as arsenic and
radionuclides. Also, some contaminants, such as lead from
corroded pipes, can enter drinking water between the
treatment plant and the tap. If these contaminants are
present in drinking water at sufficient levels, they can
lead to adverse health effects, including gastrointestinal
illnesses, nervous system and reproductive effects, and
chronic diseases such as cancer.
To protect public health, EPA sets federal health-based
standards for drinking water for public water systems.
Public water systems include community water systems—
systems that supply drinking water to 25 or more of the
same people year-round in their residences. Community
water systems serve more than 280 million people, or
about 92 percent of the U.S. population.
Public water systems must test for regulated contaminants
and treat the water, if needed, to meet the federal stan-
dards. Disinfection of drinking water effectively protects
against the risk of waterborne disease such as typhoid,
cholera, and hepatitis.
Filtration, required for
most public water sys-
tems that use surface
water, provides addi-
tional protection
against microbial
contaminants.
KEY POINTS
In 2005, 89 percent of community water system
customers were served by facilities for which
states reported no violations of EPA's health-based
drinking water standards (see graphic).
Approximately 32 million people in 2005 were served
by systems for which states reported violations of
these standards. A portion, but not all, of these peo-
ple might have been exposed to contaminants in
drinking water at levels above standards. Most of
these violations involved rules addressing microbial
contaminants or disinfection byproducts (chemicals
that can form when disinfectants, such as chlorine,
react with naturally occurring materials in water).
The level of health risk associated with violations ^
varies, depending partly on which contaminants
were involved, the extent to which a standard was
exceeded, the extent to which the distribution sys-
tem was affected, and how long the violation lasted.
Microbial violations, in particular, can be short term.
These data address drinking water from com-
munity water systems only. They do not address
the quality of drinking water that people get from
non-public supplies (such as private wells and
untreated surface water sources), from public
water systems serving transient populations (such
as roadside rest stops and campgrounds), or from
non-residential users (such as some workplaces
and schools). National data are not available for
bottled water, which is regulated by the Food
and Drug Administration.
National indicators are not available for health
effects that could be caused by contaminants in
drinking water. For example, no national indicator is
available for disease occurrence or outbreaks caused
by harmful microorganisms in drinking water.
Population Served by Community Water Systems With
No Reported Violations of EPA Health-Based Standards,
1993-2005
(A
& |
II
8 |
- H
o> J2
a! §
10U •
90-
-
-
60-
50-
-
-
-
-
-
*
"Several new standards went into effect after December 31. 2001. The
lightly shaded portion of the 2003, 2004, and 2005 columns indicates
what percent of the population would have been served by community
water systems with no reported violations if these new standards had not
gone into effect.
Data are presented by EPA fiscal year (October 1-September 30).
Source: U.S. Environmental Protection Agency, Safe Drinking Water
Information System. Federal Version, 2006
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Chapter 2 Water 15 Drinking Water
-------
a RECREATIONAL WATERS
People enjoy many recreational
activities on the nation's rivers,
lakes, and coastal waters. Several
characteristics determine
whether these waters are suitable for recreation. For
example, the levels of chemical contaminants and
disease-causing microorganisms in water affect whether
KEY POINTS
While information exists about many individual
water bodies, consistent national indicators for
recreational waters are not yet available. Many
states and localities collect information about individ-
ual water bodies in their region. States also monitor
coastal beaches for levels of certain disease-causing
bacteria and report the results to EPA. However, differ-
ent states monitor in different ways (for example, by
using different methods or monitoring more or less
the water is suitable for swimming, boating, and other
contact activities.
The condition of ecosystems and the wildlife within them,
which support recreational activities such as fishing and
bird watching, is also important. While many of these char-
acteristics can be measured at a local level, there are sever-
al barriers to compiling these data into national indicators.
frequently), making it difficult to compile the results
into national indicators.
Improved data collection could lead to suitable
indicators in several areas. For example, with a
comprehensive national system for gathering data,
scientists could develop consistent national indicators
for bacteria levels at beaches.
777/s DRAFT is intended for public comment and peer review. Please submit comments at www.regulations.gov.
16 Recreational Waters
Chapter 2 Water
-------
.-* CONSUMABLE FISH AND SHELLFISH
Fish and shellfish are an impor-
tant part of a healthy diet for
many Americans. Some fish and
shellfish from lakes, rivers, estuar-
ies, and deep ocean fisheries, as well as farmed fish and
shellfish, can contain chemicals or disease-causing organ-
isms at levels that can pose human health risks. Sources of
these contaminants include runoff from urban and agricul-
tural areas, pollutants deposited in water from the air, and
direct discharges into water bodies.
Concerns about fish and shellfish safety are higher for peo-
ple who eat a lot of fish, and groups of people—such as
infants, children, the elderly, and women who are pregnant
or might become pregnant—who can be particularly vul-
nerable to contaminants that may be present in fish.
Of particular interest in measuring the condition of con-
sumable fish and shellfish are chemicals such as mercury,
polychlorinated biphenyls (PCBs), the pesticide DDT or
diphenyl-trichloroethane, and polycyclic aromatic hydro-
carbons (PAHs), which form during the combustion of oil,
gas, and other organic substances). These compounds can
persist in sediments for a long time, increasing their poten-
tial for entering the food web and ultimately concentrating
in fish that may be eaten by people and wildlife.
KEY POINTS
Coastal sites across the nation showed varying
levels of contamination in fish tissue. Sixty-three
percent of the sites showed "low" fish tissue contamina
tion, 15 percent showed "moderate" contamination,
and 22 percent had "high" contamination based on
health-based consumption guidelines (see graphic).
PCBs, mercury, DDT, and PAHs were most often
responsible for high contamination scores. The con-
dition of coastal fish varied significantly among dif-
ferent areas of the country. The survey did not
include Hawaii, the Caribbean, the Pacific territories,
or Alaska, which is notable because more than half
the nation's commercial fish are from Alaska. .
Lake fish surveys found that several chemicals,
including mercury, dioxins and furans, PCBs, and
DDT, are widely distributed in the nation's lakes
and reservoirs. However, some other chemicals,
including certain pesticides and PAHs, were detect-
ed rarely or not at all. These data do not consider
whether the detected levels are a health concern.
The surveys did not include Hawaii, the Caribbean,
the Pacific territories, or Alaska.
While fish consumption advisories provide infor-
mation on fish from many individual water bod-
ies, these advisories cannot be compiled into a
national indicator of fish and shellfish condition.
The states and tribes that issue fish consumption
advisories use different ways of monitoring waters
and making advisory decisions, so the information
is not comparable.
There are no consistent national indicators for dis-
ease-causing organisms in fish and shellfish, or for
the biological and chemical condition of commer-
cially farmed fish and shellfish.
Contaminants in Fish From Estuarine Waters, 1997-2000
At least one
contaminant above
its guideline range
All contaminants
below their
guideline ranges
At least one
contaminant within
its guideline range.
but no exceedances
Data gathered in the lower 48 states from 1997 to 2000.
Categories are based on comparison to EPA's health risk guidelines for tish
consumption. Graphic shows the percent of estuarine sites in each category.
Source: U.S. Environmental Protection Agency. "National Coastal Condition
Report II." 2004
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Chapter 2 Water 17 Consumable Fish and Shellfish
-------
AND
Land Cover
Land Use
Wastes and the Environment
Chemicals Applied and
Released to Land
and provides food, shelter, fuel, and raw mate-
rials for people, as well as habitat for many
__ species. It is the source of many resources such
as minerals, timber, and petroleum and helps to fil-
ter the nation's water and break down wastes and
chemicals. While the amount of land in the United
States is relatively constant, how land is used
changes continuously. Changes in land use affect
the distribution and nature of land cover (such as
forests, developed land, and agricultural land) and
the condition of land and its resources.
Land is intricately connected to other environmental
resources and to human health. For example, land
cover affects the energy exchange between the
Earth's surface and atmosphere, which in turn influ-
ences climate and weather. Changes in land cover
can increase or decrease erosion, water runoff, sedi-
mentation, and flooding. Chemicals and wastes can
affect human health and the environment when
they are applied to or disposed of on land.
Many federal agencies with varying responsibilities
collect data on land resources using satellite
imagery, national surveys, and regulatory data.
These data, in general, represent only a small
sample of the total picture of land cover, land use,
waste management and disposal, chemicals used
on-land, and land contamination. States also collect
these kinds of data, but differ in their approaches,
making it difficult to compile national data on
land issues.
Contaminated Land
This DRAFT is intended for public comment\
and peer review. Please submit comments
at www.regulations.gov.
Chapter 3: Land
-------
LAND COVER
Land cover is the vegetation and
other materials, such as rock,
snow, or pavement, that are
present and visible on land.
Satellite data are frequently used to identify land cover
types over large areas. Land cover can be grouped into
six major categories: forest cover, grass cover, shrub
cover, developed land, agriculture, and "other" (which
includes ice/snow, bare rock, and other types of land
cover with limited extent).
KEY POINTS
Land cover differs from land use. Land cover is physically
obvious, while land use is determined by a government
agency or individual landowner and might not always be
visible. Because of these differences, land cover acreages
differ from land use acreages in the United States.
A number of factors affect land cover, including geology,
climate, population changes, and human activities such as
industrial and urban development, deforestation or refor-
estation, water diversion, and road building. The extent
and type of land cover in an area can affect habitat quality
and availability, species distribution, water quality, climate,
and distribution and movement of chemicals.
Forest cover and agriculture account for the two
largest acreages of land cover in the United
States. In 1992, of the approximately 2.3 billion acres
of land in the nation, 694 million acres were forest
cover, 510 million acres were agriculture, 350 million
acres were shrub cover, 307 million acres were grass
cover, and 41 million acres were developed land. These
estimates were derived from satellite data.
Land cover types vary significantly by region (see
graphic). Forest cover is predominant in the eastern
and Pacific northwest states, agriculture in the north
central states, grass cover in the central states, and
shrub cover in the Pacific southwest states. v
The total amount of forest in the United States has
remained relatively constant over recent years, but
regional variations exist. Forest cover has increased in
the Mid-Atlantic and Midwest and decreased in the
south central states and the Pacific Southwest.
Comparing and integrating land cover information
is difficult. Different agencies collect data on land
cover, often at varying times and for different purposes.
These agencies also define and classify land cover dif-
ferently and at varying levels of detail. The most recent
comprehensive data available are from 1992; satellite
data from 2001 are under development.
Land Cover, 1992
-
r
Agriculture Shrub cover
i Developed land • Water
l Forest cover Other (wetlands.
Grass cover snow/ice, rock.
mining, transitional)
Source: U.S. Geological Survey. 1992 National Land Cover Dataset
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Chapter 3 Land
19
Land Cover
-------
LAND USE
U.S. lands support many uses,
including crop production, tim-
ber production, livestock grazing,
recreation, and residential and
commercial development. Designated through zoning and
other regulations, these uses are often less physically obvi-
ous than land cover. For example, "developed land use"
can include land that has visibly developed features, such
as asphalt, concrete, and buildings, as well as undeveloped
land designated for residential or transportation use.
Land use can adversely affect numerous aspects of the
environment, including air and water quality, habitat
availability, and species distribution. In some cases, land
use can also have positive environmental effects, such as
when communities restore habitats or clean up and
redevelop contaminated lands.
KEY POINTS
Grazing, timber production, and food crop pro-
duction account for the three largest acreages of
land use in the United States. As of 2002, of the
approximately 2.3 billion acres of land in the nation, as
many as 720 million acres were used for grazing, 504
million acres for timber production, 370 million acres
for food crop production, and 107 million acres for
development. These data are based on aerial photo
interpretation and ground surveys.
Land use patterns vary significantly by region of
the country. More than three-quarters of the nation's
grazing land is in the West, and just under half the
timberland is in the East.
The amount of land used for crop production and
pasture has declined since 1982, while the amount
of developed land has increased, and timberland
has remained constant. Conversions of forestland,
cropland, and pastureland have contributed to the
increases in developed land. Additionally, highly erod-
able cropland has been removed from production.
Between 1982 and 2002, the amount of developed
land in the United States increased at nearly twice
the rate of the population (see graphic). The amount
of developed land grew by about 47 percent, while the
population grew by just over 24 percent. Population
and development trends varied in different parts of the
county. For example, in the West, the amount of land
developed closely matched population growth. In the
Northeast, the amount of developed land increased by
nearly 36 percent, while population grew by 9 percent.
The data to track land use trends are limited and
derived from many sources, which inhibits the
ability to track changes over time. Various agencies
collect land use data, often at different times and for
different purposes. Classifications of land use can also
vary, making it difficult to integrate and compare data.
Change in Population and Developed Land,
1982-2002
1982-
1987
1987-
1992
1992-
1997
1997-
2002
Change in population
Change in acreage
of developed land
Data gathered in the lower 48 states
and Hawaii, except for 1997-2002.
when data on developed land were
not available for Hawaii.
Source: U.S. Census Bureau, 1996, 2002, 2005. U.S. Department
of Agriculture, Natural Resources Conservation Service, 2000,
2004
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Chapter 3 • Land 20 Land Use
-------
WASTES AND THE ENVIRONMENT
The amount, composition, and
management of wastes provide
insight into the nation's
efficiency in using materials and
resources. Such information also can be useful in under-
standing the effects of wastes on human health and the
environment. The type and amount of waste produced in
the United States varies and can depend on the size and
activities of an organization. For example, households pri-
marily produce municipal solid waste (paper, packaging,
yard trimmings, and other materials) and small amounts
of hazardous waste. Commercial entities and institutions
produce municipal solid waste, industrial waste, and larg-
er quantities of hazardous waste. Hazardous wastes have
properties (toxicity, corrosiveness, ignitability, reactivity)
that make them potentially harmful to human health or
the environment.
KEY POINTS
Activities such as agriculture, construction/demolition,
mining, and other resource extraction and industrial
processes generate large quantities of other types of
waste. Presently, however, the United States regularly col-
lects information on only municipal solid waste and haz-
ardous waste. These two types of waste make up a small
fraction of all of the waste generated in the country.
Once wastes are generated, they must be managed-
collected, transported, stored, reused, recycled, processed
or treated, or disposed of. Because wastes can contain
hazardous chemicals, both their generation and manage-
ment have the potential to contaminate land, compro-
mise its use, or affect human health and ecological
conditions. For example, landfills have been a significant
source of methane over the last decade. In contrast,
industry has taken steps to reduce certain high-priority
chemicals (documented contaminants of air, water, land,
plants, and animals) found in waste in recent years.
Since 1990, the per capita municipal solid waste
generation rate has remained stable at 4'/2 pounds
per person per day. As the U.S. population has
increased, however, the nation has steadily generated
more municipal solid waste. Generation increased from
88 million tons in 1960 to 236 million tons in 2003.
Hazardous waste generation has declined.
Hazardous waste generation dropped from nearly
36 million tons in 1999 to 25 million tons in 2003.
Recycling or composting of municipal solid waste
increased from 6 to 31 percent over the past four
decades (see graphic). Hazardous waste recycling rose
only slightly between 1999 and 2003 and remains at
less than 10 percent.
Most waste is still disposed of on land. In 2003, 55
percent of municipal solid waste was disposed of in
landfills, compared to approximately 63 percent in
1960 (see graphic). Ninety-two percent of hazardous
waste was injected deep into the ground in permitted
wells, and the remaining 8 percent was treated and
disposed of in a manner to minimize risk to human
health and the environment.
Information about many types of waste is not cur-
rently available at the national level. Also, data are
lacking about exposure and the effects of waste
and management practices on human health and
the environment. The potential effects associated
with waste vary widely and are influenced by the sub-
stances or chemicals found in waste and how they
are managed.
Municipal Solid Waste Management, 1960-2003
250'
200-
100-
Recovery for composting
Landfill or other disposal
0
1960 1965 1970 1975 1981) 1985 1990 1995 2000
Source: U.S. Environmental Protection Agency. Office of Solid
Waste and Emergency Response. 2005
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Chapter 3 Land 21 Wastes and the Environment
-------
CHEMICALS APPL ED AND RE EASED TO LAND
Chemicals are commonly used
in manufacturing, in food and
consumer products, and in
efforts to manage diseases. They
can be intentionally applied to land for purposes of
increasing crop yields and controlling pests, or in some
cases, accidentally spilled on land. Some chemicals also
occur naturally or can enter the environment through
acts of nature, such as volcanoes and hurricanes.
Chemicals released or applied to the environment can
pose a range of challenges to human health and the
environment. Some chemicals break down quickly in
the environment, while others persist for long periods of
time and can accumulate in the food web. The volume
or mass of a chemical is not proportional to its toxicity.
KEY POINTS
Some chemicals have no known health effects, but others
can lead to health problems if people are exposed to them
in sufficient quantities. The effects of long-term exposure
to chemicals are often
unknown. In addi-
tion, some — -^
chemicals can
harm ecosys-
tems, such as
excess fertiliz-
ers carried in
runoff, which
can affect water
quality and aquatic life.
Certain toxic chemicals in industrial waste materi-
als decreased by more than 4 billion pounds (14
percent) between 1998 and 2003 (see graphic).
These chemicals are subject to reporting to EPA under
the Toxics Release Inventory (TRI) program. Only chemi-
cals subject to a consistent set of annual reporting
requirements for all years from 1998 to 2003 are
shown. In 2003, the quantities of TRI chemicals associ-
ated with production-related wastes totaled nearly 24
billion pounds. The metal mining industry accounted
for 38 percent of the total TRI chemicals in production-
related wastes released to the environment.
Over the past 40 years, the use of fertilizers,
including nitrogen, phosphate, and potash, has
increased nearly three-fold. The combined use of
these three chemicals rose from 46 pounds per acre
per year in 1960 to 1 31 pounds per acre in 2003.
Nitrogen accounted for the steepest increase. While
fertilizers are not inherently harmful, they have the
potential to contaminate ground and surface water
when applied improperly or in excessive quantities.
In recent years, food samples showed declining
amounts of detectable pesticide residues. In 1994,
38 percent of the food sampled showed no detectable
amounts of pesticide residue. By 2002, 58 percent
showed no detectable amounts. Foods tested include
fruits, vegetables, grains, meat, and dairy products.
Data about chemicals used on land are limited.
Some data are available on pesticide and fertilizer use
on agricultural lands. Agencies collect national informa-
tion on only a fraction of all chemicals used in the
United States, however. Consistent national indicators
are lacking regarding when, where, and how frequent-
ly chemicals are applied to land and the potential
impact when they contain toxic constituents.
Disposition of Toxics Release Inventory
Chemical Waste, 1998-2003
lion pounds)
fO W J*
in o o
Toxic chemicals (bi
3 cn o e/i c
280
68
8.3
3.6
9.2
280
6.9
9.0
3.4
8.6
32?
6.3
128
36
9.6
25.9
5.2
8.4
3.5
8.9
1996 1999 2000 2001
24.9
4.3
7.9
3.7
9.0
o-a q
4.0
8.1
3.4
8.4
2002 2003
Source: U.S. Environmental Protection Agency. a Re(eased
Toxics Release Inventory. 2005 a Trea(ed
n Recovered
for energy
Q Recycled
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Chapter 3 * Land 22 Chemicals Applied and Released to Land
-------
CONTAMINATED LAND
Contaminated lands range from
abandoned properties in inner
cities to large areas of land once
used for industrial or mining
activities. Improper handling or disposal of toxic and
hazardous materials and wastes, deposition of toxic sub-
stances on land via winds or water, and accidental spills
can all contaminate land. Except for spills and natural
events, most land contamination is the result of historical
activities that are no longer practiced.
The Comprehensive Environmental Response, Compen-
sation, and Liability Act, also known as "Superfund," and
the Resource Conservation and Recovery Act (RCRA) are
two of the major federal laws governing contaminated
lands to protect human health and the environment.
KEY POINTS
The most toxic abandoned waste sites in the nation are
listed on the Superfund National Priorities List (NPL).
High-priority facilities subject to cleanup under RCRA are
included in the RCRA Cleanup
Baseline.
Completing cleanups
at these complex
sites can take years
and even decades;
therefore, EPA tracks
whether people are
coming in contact with
contamination above levels of
concern, and whether contaminated ground water is
spreading above levels of concern.
KEEP OUT
Between 2002 and 2005, the percentage of
Superfund NPL sites where human contact with
contamination was not reasonably expected to
occur remained relatively constant at 80 percent
(see graphic). However, between 2000 and 2005,
the percentage of RCRA Cleanup Baseline sites
where human contact with contamination was not
reasonably expected to occur increased from 37 to
96 percent. These increases were partly due to actions
to prevent contact with contamination and partly the
result of sites with insufficient data being reclassified
after completing site investigations. During these .
periods, the total number of Superfund NPL sites
increased from 1,498 to 1,547, while the number of
RCRA Cleanup Baseline sites remained constant at
1,714.
Between 2002 and 2005, sites where contaminat-
ed ground water was not spreading above levels
of concern increased from 51 to 61 percent of
Superfund NPL sites and from 32 to 78 percent
of RCRA Cleanup Baseline facilities. The increases
were partly due to actions to mitigate the spread of
contaminated ground water and partly due to the
completion of site investigations.
The total number and extent of contaminated sites
nationwide is not known, nor are their specific
effects on human health and the environment.
Although EPA tracks the most contaminated sites
through the RCRA Cleanup Baseline and Superfund
NPL, these sites do not represent the full extent of con-
taminated land in the United States. Many other sites
managed by local, state, and other federal authorities
are not inventoried at the national level.
Human Contact with Contamination
at Superfund National Priorities List (NPL)
Sites, 2002-2005
2.000
1,500-
1.000
1498 1.518 1,529
192
121
1,185
(79%)
182
1,217
(80%)
176
1,250
(82%)
1.547
164
148
1,235
(80%)
2002
2003
2004 2005
"Contact likely" means that there is a reasonable expectation that
humans are exposed to contamination above health-based
standards.
Data are presented by EPA fiscal year (October 1 - September 30).
Source: U.S. Environmental Protection Agency, Office of Solid
Waste and Emergency Response. 2006
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Chapter 3 Land 23 Contaminated Land
-------
H EALTH
Health Status
Diseases and Health
Contaminants
any factors can influence human health,
including exposure to environmental con-
. * . taminants. People can be exposed to envi-
ronmental contaminants in a variety of ways, and
many contaminants are known or suspected of
causing human disease. The relationships among
environmental contaminants, exposure, and human
disease are complex, however. Despite these com-
plexities, studying overall patterns of disease or
exposure helps determine where further study or
public health interventions could be needed.
For people to experience adverse health effects from
exposure to an environmental contaminant, various
events must occur. First, a contaminant released
from its source requires some sort of contact (via air,
water, or land) with a person and then must enter
the body through inhalation, ingestion, or skin con-
tact. Additionally, a contaminant needs to be pres-
ent within the body at sufficient doses to ultimately
result in a health effect. Understanding the connec-
tions between environmental exposure and adverse
health effects is particularly challenging because
many risk factors other than the environment-
including genetics, personal behavior, and health
care—also affect health.
Health and exposure data are drawn from many
sources. These include records of vital statistics, such
as births and deaths; surveys and questionnaires;
and surveillance activities, such as cancer registries
and other systems. As used in this report, these data
are representative of the national population. They
are not based on data from targeted populations or
tied to specific exposures or releases.
At present, national-level health and exposure indi-
cators cannot be used to demonstrate a cause-and-
effect relationship between exposure to an
environmental contaminant and an adverse health
effect. Instead, these national-level data can help
researchers track overall trends in population health,
disease, and exposure, including trends across differ-
ent age, gender, race, and ethnic groups.
This DRAFT is intended for public comment\
and peer review. Please submit comments
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Chapter 4: Human Health
-------
1
HEALTH STATUS
A nation's health status can be
measured in many ways. Life
expectancy and death rates are
generally regarded as good
overall measures of population health because they rep-
resent the combined effects of many different risk fac-
tors. Infant death rates are particularly useful because
they indicate the current health status of the population,
predict the health of the next generation, and reflect the
overall state of maternal health.
KEY POINTS
Tracking these kinds of broad health measures helps to
identify general patterns in the nation's health status and
lay a foundation for studying trends in specific diseases
and conditions. In addition, such tracking can help iden-
tify possible environmental factors that could contribute
to the diseases or conditions that are the leading causes
of death in the United States.
Overall, the health of the U.S. population has con-
tinued to improve. Mortality rates continue to decline,
and life expectancy continues to increase, due to factors
such as improved medical care over the past few
decades.
Life expectancies in the United States are lower
than in many other countries. In 2003, the United
States ranked 34th in life expectancy for men and 35th
for women among the 192 nations and states that are
members of the World Health Organization.
The three leading causes of death in the United
States—heart disease, cancer, and stroke—remain
unchanged since 1999. Measures of premature death
show that injuries are the leading cause of death,
followed by cancer and heart disease.
Infant mortality in the United States shows a long-
term decline, although it remains among the high-
est in the industrialized world at seven deaths per
every 1,000 live births in 2002. In 2002, U.S. infant
mortality increased for the first time since 1958. U.S.
infant mortality rates were two to three times higher
than the lowest rates reported worldwide.
Although national health is generally improving,
racial, ethnic, and gender differences persist. The
mortality rate for black infants is still more than twice
that of white or Hispanic infants. The gap in life
expectancy between the black and white populations,
and male and female populations, is approximately
five years (see graphic). In 2003, mortality rates were
almost a third higher for black Americans than for
white Americans. Currently, data available for other
racial or ethnic groups enable only limited analysis.
Life expectancy and death rates do not address
other aspects of health such as perceived well-
being or quality of life. Though life expectancy and
death rates are widely accepted measures of health
status, they alone do not completely describe the
nation's health.
Life Expectancy by Race and Sex, 1940-2003
1940
1950
1950
1970
1980
1990 2000
Source: National Center for Health
Statistics. United States life tables.
2006
All groups
Male (white)
Female (while)
- Male (black)
Female (black)
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Chapter 4 Human Health 25 Health Status
-------
' .
J
DISEASES AND HEALTH CONDITIONS
Exposure to environmental
contaminants has been linked to
many human diseases and con-
ditions, including cancer, cardio-
vascular disease, respiratory disease, some infectious
diseases, and low birthweight, among others. These links
have been established through well-designed studies
with specified populations and specific environmental
exposures. Many other risk factors can also lead to these
diseases and conditions, however. For all the diseases
KEY POINTS
and conditions described here, exposure to environmen-
tal contaminants is one of the associated risk factors.
Tracking the occurrence of these human diseases and
conditions at the national level helps identify general
patterns or trends over time and across subgroups.
Some notable differences are seen across different age
groups, races, or ethnic groups for many conditions,
such as heart and lung conditions, cancer, asthma,
and some birth outcomes, such as birth defects, one-
term deliveries,and low birthweight.
As the U.S. population ages, many chronic dis-
eases—including various cancers and heart and lung
diseases—are occurring more frequently in adults.
For a number of these diseases, however, occur-
rence has stabilized in recent years. The annual inci-
dence (proportion of new cases in a year) of cancer
increased slowly from the early 1970s to the early 1990s
and then leveled off. Rates for cardiovascular disease
and chronic obstructive pulmonary disease remained
fairly constant between 1997 and 2004, though death
rates associated with these diseases declined.
There has been a slight rise in the incidence of
cancer in children ages 0 to 19 years since the early
1970s. Leukemia and cancers of the brain and nervous
system remain the leading cancers in children. White
children develop cancer almost twice as often as black
children.
Asthma rates are higher in children and adolescents
than in adults, with some distinct patterns across
races (see graphic). Between 1980 and 1996, child-
hood asthma rates increased about 4 percent each
year, with no major shifts observed since 1997. Based
on data from 2004, approximately 9 million children
(about one in eight) in the United States have asthma.
American Indians/Alaska Natives and blacks experience
the highest asthma rates, compared to those reported
in other races. Rates are lower in Hispanic/Latino chil-
dren and adults than in non-Hispanics/Latinos.
No notable patterns were observed for most
reportable infectious diseases between 1995 and
2004. However, some increases were reported in 2002,
2003, and 2004 in Lyme disease, Rocky Mountain spot-
ted fever, and Legionnaires' disease.
The proportion of mothers that gave birth early
(before 37 weeks of gestation) increased by 14
percent since 1990, with a smaller increase from
1995 to 2002. Data from 1995 to 2002 also show
that black mothers were about one-and-a-half to two
times more likely to give birth early than white moth-
ers. Also, black babies born at full term were more
likely to have a low birthweight (less than 2,500
grams, or 5 pounds 8 ounces) than white babies.
These indicators provide important insights on dis-
ease patterns,'but cannot be used alone to under-
stand the role of environmental exposures. This is
because these diseases and conditions are linked to
other causes besides environmental exposures. Also,
national indicators are not available for other diseases
with possible environmental links, such as behavioral
and reproductive disorders, and other diseases still
being studied for possible connections to the environ-
ment, like Alzheimer's disease and diabetes.
Asthma Prevalence by Race, 2002-2004
o>
200
160
120
80
40
I
All groups
White
i Black
American Indian/
Alaska Native
i Asian
Children
(0-17 years)
Adults
(18+years)
Asthma prevalence represents individuals who were ever told that they have
asthma.
Data were collected from 2002 to 2004.
Source: National Center for Hearth Statistics. "Health Data for All Ages." 2006
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Chapter 4 * Human Health 26 Diseases and Health Conditions
-------
EXPOSURE TO ENVIRONMENTAL CONTAMINANTS
People are exposed to many dif-
ferent contaminants in the envi-
ronment. Although researchers
can measure the levels of con-
taminants in air, water, and land, these measurements
cannot reveal whether, or how much of, those chemicals
have contacted or entered people's bodies.
Biomonitoring is used to measure internal body levels of
a contaminant (or substances produced when the body
interacts with the contaminant) in human blood, urine,
KEY POINTS
or tissues. This type of direct measure offers more infor-
mation about the extent of exposure to people than
environmental levels alone.
Biomonitoring data can help track levels of people's
exposure to environmental contaminants, but cannot
be used to determine how people might have been
exposed to a contaminant, or in most cases whether
they will become sick. Currently, biomonitoring tech-
niques exist for only a few of the many environmental
contaminants.
Blood lead levels show a steady decline since the
1980s. Lead can harm the brain, nervous system, and
other organ systems. Children aged 1 to 5 years have
the greatest health risk from lead exposure because
their systems are still developing. Between 1999 and
2002, 1.6 percent of children aged 1 to 5 years had
elevated blood lead levels, decreasing from 88 percent
in the late 1970s. The Centers for Disease Control and
Prevention define elevated blood lead levels as 10
micrograms of lead per deciliter of blood.
About 6 percent of women of child-bearing
age had at least 5.8 parts per billion of mercury
in their blood from 1999 to 2002. EPA has deter-
mined that children born to women with blood
concentrations of mercury above 5.8 parts per bil-
lion are at increased risk of adverse health effects.
Exposure to environmental tobacco smoke
among nonsmokers decreased considerably in
the last decade (see graphic). Nonsmokers who
are exposed to environmental tobacco smoke can
have elevated levels of cotinine in their blood.
Cotinine is a substance that forms in the body
following exposure to nicotine.
Baseline measurements of exposure are also
available for other biomonitoring indicators.
These include cadmium, a metal that enters the
environment through natural and man-made
processes; phthalates, used to soften and increase
flexibility of plastics and vinyl; persistent organic
pollutants (POPs); man-made chemicals (such as
polychlorinated biphenyls, dioxins, and furans)
that can remain in the environment for years or
decades; and pesticides, including chemicals
to control weeds, insects, and other organisms.
These baseline measurements can be used in the future
to track possible trends.
Biomonitoring data currently have limitations as
indicators of exposure. Because biomonitoring data
do not include the sources of exposure, these indica-
tors alone do not indicate whether measured levels
are related to environmental exposures.
Blood Cotinine Concentrations in Children Aged 4-17
by Race and Ethnicity, 1988-1994 Versus 1999-2002
100 •
80 •
i
I 60-I
D
-
40 •
20 •
Total
63.7
23.7
41.0
16.5
Black.
non-Hispanic
57.9
36.6
59.4
22.4
Mexican
American
72.8
10.7
41.3
5.2
White,
non-Hispanic
62.5
242
35.5
19.1
1988- 1999-
1994 2002
1988- 1999-
1994 2002
1988-
1994
1999- 1988- 1999-
2002 1994 2002
Concentration:
DO.05to1.Ong/mL
D More than 1.0 ng/mL
Cotinine concentrations are reported for nonsmoking
children only.
Concentrations are measured in nanograms of cotinine
per miililiter of blood (ng/mL).
Source: Forum on Child and Family Statistics.
"America's Children in Brief: Key National Indicators of Well-Being," 2005: data
collected by the National Health and Nutrition Examination Survey (NHANES)
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Chapter 4 Human Health 27 Exposure to Environmental Contaminants
-------
ECOLOGICAL
NDITION
'atterns in
^logical Systems
iologic
Ecological Processes
Physical and
Chemical Attributes
of Ecological Systems
cological condition refers to the state of the
physical, chemical, and biological characteris-
—.tics of the environment and the processes and
interactions that connect them. Ecological condi-
tion reflects a wide array of factors, including the
natural development of plant and animal commu-
nities, natural disturbances, resource management,
pollution, and invasive species.
One approach to assessing the nation's ecological
condition is to examine its essential attributes,
including the extent, distribution, and diversity of
ecosystems; ecological processes; physical and
chemical attributes; and exposure to pollutants.
Human activities and natural factors can directly or
indirectly affect one or more of these attributes,
resulting in changes to an ecological system. For
example, plant growth might increase in response
to heavy rainfalls or decrease in response to con-
taminant exposure. Such changes can affect the
way an ecosystem functions and can have positive
or negative consequences for society—such as by
altering crop, timber, or fishery yields.
Measuring the nation's ecological condition is chal-
lenging. It is not as straightforward as measuring
pollutant levels in air, water, and soil. For example,
there are numerous groups of animals and plants,
and indicators are available for only some of these.
Major groups known to be undergoing changes,
such as amphibians, are not captured by the
available indicators.
Ecological Exposure
to Contaminants
This DRAFT is intended for public comment}
and peer review. Please submit comments
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Chapter 5: Ecological Condition
-------
PATTERNS IN ECOLOGICAL SYSTEMS
Ecological systems—ranging
from forests and watersheds to
wetlands and coral reefs—make
up the environment. Changes in
patterns of the extent and distribution of ecological sys-
tems have a fundamental influence on the health of the
planet and the people who depend on these systems.
For example, the extent of a forest affects both air and
water quality, while the type of trees in a forest influ-
ences ecosystem structure and function, including which
animals and plants are present.
Ecological systems are not isolated, but connected to
one another. Connectivity refers to the way in which
matter, energy, and organisms flow within and among
ecosystems. Fragmentation refers to the breaking up of
an ecological system into smaller, more isolated parts.
When ecological systems become fragmented, habitat is
broken up into patches interspersed with other habitat
types that may not support the species that were origi-
nally present.
Patterns in ecological systems can change naturally over
time as a result of geological and climatic changes, or
more quickly due to events such as extreme weather or
wildfires. They also can change in response to human
activities, such as urbanization, agriculture, forest man-
agement, and introduction of invasive species.
The impact of such changes varies significantly depend-
ing on their geographic scale. For example, a storm
could create a gap in a forest canopy that only affects
the immediate area for several decades. In contrast,
widespread loss of wetlands over a large region could
permanently shift bird migration routes or make coast-
lines more vulnerable to hurricanes.
KEY POINTS
Over the past century, the total amount of forest
land has remained relatively constant, although
forest types have changed regionally (see graphic).
This change is primarily due to changing agriculture
and development patterns. Forest extent has increased
in the Mid-Atlantic and Midwest and decreased in the
West and Southwest. Although total forest extent has
decreased in the West, acreages of fir-spruce and other
forest types have increased over the past 50 years, while
other forest types, including many pine forests, have
decreased.
Nationwide, 47 percent
of forests are highly
fragmented. Human
activities cause most of the
forest fragmentation in the
East, while natural factors,
such as arid southern
slopes, rock outcroppings,
and forest fires, cause
most of the fragmentation
in the West.
Some ecological systems
remain highly connected
and intact. In the North-
east and Pacific North-
west, no fragmentation
has been observed in
more than 30 percent of
\
the forests. In the Southeast, about 40 percent of the
forest, wetlands, and open water ecological systems
remain connected to each other.
Much of the information about patterns of eco-
logical systems is more than a decade old, limiting
the ability to track recent trends. Little information
is available on the extent of ecological systems other
than forests and wetlands, or about the effects of frag-
mentation on biodiversity and ecological processes
at different geographic scales.
Timberland Area in the West by Forest Type, 1953-2002
-
-
-
-
Douglas-lir Pondetosa-Jeftrey Fir-spruce Hemlock-Stika Lodgepole pine Western hardwood
pine spruce types
Graphic depicts data for states in the western United States (including Alaska and
Hawaii), based on U.S. Department of Agriculture Forest Service reporting regions
(see map at right).
Data Source: Smith et al.. "Forest Resources of the United States, 1997" and
"Forest Resources ot the United States, 2002," 2001 and 2004
East
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Chapter 5 Ecological Condition
29
Patterns in Ecological Systems
-------
B| BIOLOGICAL DIVERSITY
Biological diversity, or biodiversi-
ty, refers to the amount of varia-
tion within biological systems.
This diversity encompasses
multiple levels—from the genetic makeup of a single
organism to the composition of an entire ecosystem.
Biological diversity provides many tangible benefits to
society, including medicines and crops; for many peo-
ple, it also contributes in important ways to the quality
of life.
Trends in the number and composition of species within
an ecological system are important indicators of its
health and robustness. Scientists generally agree that as
the number of species in an ecological system declines,
the system is less able to recover from stress. These rela-
tionships are not straightforward and can vary in
degree, depending on the types of species introduced
or removed from a system.
Diversity arises over time when adaptation results in
new species that fill available niches in the environment.
This is a dynamic process involving colonization,
KEY POINTS
Over the past four decades, watersheds covering
about 24 percent of the land in the lower 48
states have lost one tenth of their freshwater fish
species. Losses were especially severe in the
Southwest and the Great Lakes, where eight major
watersheds lost more than half their native fish. Fish
diversity can decline from a number of different
factors, such as pollution, habitat alteration, fish-
eries management, and invasive species. In con-
trast, watersheds covering about 21 percent of
land area have retained their entire composition of
species.
In recent years, changes (both decreases and
increases) have occurred in bird populations
in various habitats. Changes in bird populations
reflect changes in landscape and habitat, food avail-
ability and quality, toxic chemical exposure, and cli-
mate. Since 1966, substantial decreases occurred in
70 percent of grassland species and 36 percent of
shrubland species. Substantial increases occurred in
40 percent of urban species and 38 percent of water
and wetland species (see graphic).
evolution of species adapted to new conditions, and
extinction of species that are less well adapted to a
changing environment. This process has occurred over
millions of years across large geographic areas, punctu-
ated occasionally by significant natural events such as
meteor strikes, periods of intense volcanic activity, and
ice ages.
Human activities—such as urbanization, water manage-
ment practices, and land-use changes—can have pro-
found effects on biological diversity, and in a much
shorter timeframe. For example, in
sewage-polluted waters, dense beds
of a single species, sludgeworms,
can replace the more diverse
communities of bottom-dwelling
organisms ordinarily present.
Invasive species also can have
widespread effects. When the sea
lamprey was introduced to the Great
Lakes, for instance, sweeping changes
occurred throughout the entire food web.
'
Consistent national indicators are not available
for several aspects of biological diversity. These
include major groups of animals such as amphibians,
reptiles, and mammals; plants; and the numbers of
threatened, endangered, and invasive species.
Change in Bird Populations by Habitat Type, 1966-2003
200
175
150
B 100
I »
= 50
25-
Population change:
• Substantial increase
D No substantial change
D Substantial decrease
Grassland
Shrubland
Woodland
Habitat type
Urban
Water/
wetland
Data gathered by the North American Breeding Bird Survey, which covers
the lower 48 states and southern Canada.
Substantial increases or decreases are those in which the observed
populations increased or decreased by more than two-thirds.
Source: Audubon Society, "State of the Birds USA 2004," 2004
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30
Chapter 5 * Ecological Condition
Biological Diversity
-------
»-
ECOLOGICAL PROCESSES
Ecological systems are sustained
by biological, physical, and
chemical processes. One such
process is carbon cycling.
During photosynthesis, plants use the sun's energy to
produce organic matter from carbon dioxide. This
organic matter provides the food at the base of the food
web. Carbon dioxide is regenerated through the respira-
tion of animals in the food web and through decomposi-
tion by the microbial community when organisms die.
Organisms that produce organic matter from inorganic
matter using energy from the sun are known as "primary
producers." They range in size from microscopic ocean
plants to the giant redwoods of California. Decreases in
primary production affect all the animal populations that
depend on that production for food. Too much primary
production (for example, algal blooms in water bodies)
is also a problem.
KEY POINTS
Many human and natural factors impact ecological
processes, including pollution and changes in land use,
such as conversion of forests to urban or agricultural
land. Trends in ecological processes, such as the cycling
of carbon and carbon storage, provide insight into the
structure and function of ecological communities and
how human and natural factors affect them.
Although there are numerous components of the carbon
cycle, an indicator is available for one of these compo-
nents—carbon storage in
forests. This indicator
provides insight into
a portion of the car-
bon cycle for forest
ecosystems.
The net storage of carbon in forests increased
between the 1950s and 1980s, but declined some-
what in the 1990s. Net storage is the growth of trees
minus the amount of carbon removed in harvested tim-
ber. The greatest amount of carbon is being stored in
the North, followed by the Rocky Mountain region.
Carbon storage has decreased in the South, possibly
due to an increase in harvesting compared to growth
(see graphic). \
A number of gaps exist in understanding trends in
ecological processes. Currently, there are no reliable
national indicators for the retention and processing of
nutrients, primary production in aquatic systems, and
reproduction and growth rates for plant and animal
populations.
s
11
is
11
11
_ -c
11
2 §
ft
Carbon Storage in Forests by Region, 1953-1996
100
75-
50-
25-
-
-25 -
North
South
Rocky
Mountains
Pacific
Coast
K H II HK
TBBT
1953-1962
1963-1976
197M986
1987-1996
Data gathered in the lower 48 states.
Source: U.S. Department of Agriculture, Forest Inventory and Analysis Program, 2005
Rocky
Mountains
North
Pacific/
Coast
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Chapters Ecological Condition 31 Ecological Processes
-------
PHYSICAL AND CHEMICAL ATTRIBUTES OF ECOLOGICAL SYSTEMS
Physical attributes of ecological
systems include air temperature,
light, rainfall, and sea level.
Chemical attributes include dis-
solved oxygen, nutrient levels, acidity, and salinity. These
attributes shape evolution, drive ecological processes,
and govern the nature of ecological systems. Even small
changes in these attributes, such as changes in the acidi-
ty of a stream or the timing of rainfall in a desert, can
have potentially large effects on ecological systems.
As species evolve, they respond to and reflect the physi-
cal and chemical attributes of the ecological systems in
which they live. For example, species that evolved in
KEY POINTS
Since 1901, temperatures in the lower 48 states
rose at an average rate of 0.11 F per decade
(1.1 °F per century); this rate increased to 0.56°F
per decade from 1979 to the present (see graph-
ic). Global temperature has risen 0.1 TF per decade
since 1901 and 0.32°F per decade since 1979 (see
graphic). This trend is consistent with the retreat of
mountain glaciers, reduction in the extent of snow-
cover, earlier spring melting of ice on rivers and lakes,
and increases in sea-surface temperature.
Sea levels rose steadily at many coastal ^Vv
locations between 1950 and 1999, particularly
along the mid-Atlantic coast (3 to 6 millimeters
per year) and at two sites in Louisiana (as high as
9 to 12 millimeters per year). These rates are meas-
ures of relative sea level rise, which accounts for sea
and land height changes but does not distinguish
between the two. These rates are based on tidal
gauge monitoring. Sea level rise can alter the ecolog-
ical conditions in coastal areas, especially at low land
elevations. Effects can include increased flooding and
loss of freshwater systems as they are transformed
into inland salt waters or open coastal waters.
About 25 percent of the nation's wadeable
streams show significant evidence of excess fine
sediments, which can diminish habitat for aquatic
life. More than half the nation's wadeable streams,
however, have no substantial changes in sedimenta-
tion. Various land use practices, as well as modifica-
tions in stream flows, can lead to excess
sedimentation in streams.
Many gaps remain in assessing national trends for
the physical and chemical attributes of ecological
systems. Recent monitoring programs have provided a
tropical waters require higher, less variable temperatures
than species that evolved in temperate waters, where
average temperatures are lower and fluctuate more.
Similarly, periodic floods or fires are essential to sustain
many species in areas where such events have occurred
over thousands or millions of years.
Many factors can alter the physical and chemical char-
acteristics of ecological systems. For example, acid rain
can increase the acidity of lakes in some regions. Rivers
can alter the flooding and sedimentation processes that
sustain particular types of systems, such as wetlands.
Changes in climate can alter species diversity and nearly
every aspect of ecological structure and function.
baseline for national trends in nutrients, acidity, and
other factors in streams and estuaries. However, there
still is a lack of trend data or historical baselines for
some attributes, such as water transparency in lakes
and long-term patterns of flooding and fires.
U.S. and Global Mean Temperatures. 1901-2005
U.S. temperature anomalies
1
I.
§
i- -1
•
J -2
li,ll..l,lrV,lJrfr
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
1 5
Global temperature anomalies
i
05
00
-1.0-
-1.5
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
U.S. data gathered in the lower 48 states.
"Anomaly" is the difference between the observed temperature and a stan-
dard that was chosen for comparison. In this case, the standard is the
average temperature over the period 1961-1990.
Source: National Oceanic and Atmospheric Administration, National
Climatic Data Center, 2006
This DRAFT is intended for public comment and peer review. Please submit comments at www.regulations.gov.
32
Chapter 5 Ecological Condition
Physical and Chemical Attributes of Ecological Systems
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ECOLOGICAL EXPOSURE TO CONTAMINANTS
Plants and animals can be
exposed to chemicals in the
environment through air, water,
and food. Once inside an organ-
ism, some of these chemicals concentrate in the tissues
and build up over time with repeated exposure. This
process is called bioaccumulation.
If concentrations of these chemicals are too great, the
reproduction, health, or survival of the individual plant
or animal—or organisms that consume it—can be
threatened. If enough individuals in a species (or more
than one species) are affected, changes in the ecosystem
structure and function can result.
Measurements of exposure include chemical concentra-
tions in plant and animal tissues. Direct observations of
organisms (such as signs of
damage to plant foliage
from ozone pollution) also * 9
can indicate exposure to
contaminants.
KEY POINTS
Forest plants in some areas of the country show
injury from ozone pollution (see graphic). The
Mid-Atlantic and Southeast show the highest levels of
injury, while the West and Northwest show no dam-
age. Ozone pollution in the lower atmosphere can
significantly affect forest ecosystems. Damage to
leaves is usually the first visible sign of injury to
plants from ozone exposure.
Tissues from both coastal and freshwater fish
contain bioaccumulative chemicals, such as the
pesticide DDT or diphenyl-trichloroethane, mer-
cury, and polychlorinated biphenyls (PCBs).
While exposure to these chemicals is occurring
at variable levels throughout the country, scien-
tists have not fully assessed the ecological
effects of these exposures. These chemicals are
known to affect coastal and freshwater fish species,
but there are currently no national threshold levels
for harmful effects to fish.
No consistent national indicators are available
that measure the level of chemicals in plants or
in wildlife other than fish. Therefore, no national
trends are available for exposure of plants and ani-
mals to many common environmental pollutants.
Ozone Injury to Forest Plants by EPA Region, 2002
Region 1 Region 2 Region 3
Region 7
Region 8
Region 9
Region 10
Data gathered from 945 monitoring sites
in 41 states. Graphic shows the percent
of monitoring sites in each category.
Source: U.S. Department of Agriculture
Forest Service, Forest Health Monitoring
Program database, 2006
EPA Regions
O
-------
CONCLUSION
The topics presented in this document provide important insight into what
scientists know—and do not know—about current conditions and trends for
the nation's air, water, land, human health, and ecological systems.
This information is based on environmental indicators and is presented at a
national or regional level. Many other sources on the environment are avail-
able, including some that address issues at a more local level. EPA's Web site,
www.epa.gov, is a good starting place to get more information on a particular
topic or on a specific city or region of the country. Links to individual state
environmental departments are available at:
www.epa.gov/epahome/state.htm.
EPA is just one of many organizations working to fill the gaps in our under-
standing of the environment. As those gaps are filled, a more complete pic-
ture of the nation's environment will emerge.
EPA plans to report periodically on the state of the environment through pub-
lications like EPA's 2007 Report on the Environment: Highlights of National Trends
and EPA's 2007 Report on the Environment: Science Report. The electronic Report
on the Environment (www.epa.gov/xxx) will report new data as they become
available and allow users to offer suggestions for making this report more use-
ful. Your input is welcome.
The content of Highlights of National Trends is derived from EPA's 2007 Report
on the Environment: Science Report, which features detailed information on
86 environmental indicators. A subset these indicators is presented in this
document.
EPA selected indicators to highlight in this document based on their com-
pleteness, importance to the public and the scientific community, ability to
show a significant trend, and ability to address a key environmental ques-
tion. Indicators developed since EPA's Draft Report on the Environment 2003
were also given priority.
rNTAL INDICATORS
The indicators used in the Report on the
Environment:
• Rely on actual measurements of environ-
mental and human health conditions over
time.
• Meet a set of standards, which include quali-
ty, accuracy, relevance, and comparability.
• Were reviewed by an independent scientific
panel to ensure that they meet these stan-
dards.
Are national (or in some cases regional) in
coverage. They do not describe trends or
conditions of a specific locale.
Come from many governmental and non-
governmental organizations, which collect
data at different time periods and for varying
purposes.
Can only partially answer the key questions.
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has
not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Please submit comments at www.regulations.gov.
Conclusion
34
-------
LIST OF INDICATORS
Indicators included in EPA's 2007 Report on the Environment: Science Report are listed below, along with the key environmental question
each indicator attempts to answer. Indicators with an asterisk are featured in Highlights of National Trends.
AIR
OUTDOOR Am
What are the trends in outdoor
air quality and their effects
on human health and the
environment?
• Carbon Monoxide Emissions*
• Ambient Concentrations of
Carbon Monoxide*
• Lead Emissions*
• Ambient Concentrations of Lead*
• Nitrogen Oxides Emissions*
• Ambient Concentrations of
Nitrogen Dioxide*
• Volatile Organic Compounds
Emissions*
• Ambient Concentrations of
Ozone*
• Ozone Injury to Forest Plants
• Participate Matter Emissions*
• Ambient Concentrations of
Particulate Matter*
• Sulfur Dioxide Emissions*
• Percent of Days With Air Quality
Index Values Greater Than 100
• Mercury Emissions*
• Air Toxics Emissions*
• Ambient Concentrations of
Benzene*
• Ozone and Particulate Matter
Concentrations for U.S. Counties
in the U.S./ Mexico Border
Region
• Ambient Concentrations of
Manganese Compounds in EPA
Region 5
ACID RAIN AND REGIONAL HAZE
What are the trends in outdoor
air quality and their effects
on human health and the
environment?
• Nitrogen Oxides Emissions*
• Regional Haze*
• Sulfur Dioxide Emissions*
• Acid Deposition*
• Lake and Stream Acidity*
• Particulate Matter Emissions
OZONE DEPLETION
What are the trends in outdoor
air quality and their effects
on human health and the
environment?
• Concentrations of Ozone-
Depleting Substances*
• Ozone Levels Over North
America*
GREENHOUSE CASES
What are the trends in green-
house gas emissions and con-
centrations?
• U.S. Greenhouse Gas Emissions*
• Atmospheric Concentrations of
Greenhouse Gases*
INDOOR AIR
What are the trends in indoor
air quality and their effects on
human health?
• U.S. Homes Above EPA's Radon
Action Level*
• Blood Cotinine Level*
WATER
FRESH SURFACE WATERS
What are the trends in extent and
condition of fresh surface waters
and their effects on human health
and the environment?
• High and Low Stream Flows*
• Streambed Stability in
Wadeable Streams
• Nitrogen and Phosphorus in
Wadeable Streams*
• Nitrogen and Phosphorus in
Streams in Agricultural
Watersheds
• Nitrogen and Phosphorus
Discharge from Large Rivers*
• Pesticides in Streams in
Agricultural Watersheds
• Benthic Macroinvertebrates in
Wadeable Streams*
• Lake and Stream Acidity*
GROUND WATER
What are the trends in extent
and condition of ground water
and their effects on human
health and the environment?
• Nitrates and Pesticides in Shallow
Ground Water in Agricultural
Watersheds*
WETLANDS
What are the trends in extent
and condition of wetlands and
their effects on human health
and the environment?
• Wetland Extent, Change, and
Sources of Change*
COASTAL WATERS
What are the trends in extent
and condition of coastal waters
and their effects on human
health and the environment?
• Trophic State of Coastal Waters*
• Coastal Sediment Quality
• Coastal Benthic Communities*
• Submerged Aquatic Vegetation in
the Chesapeake Bay*
• Hypoxia in the Gulf of Mexico
and Long Island Sound*
• Harmful Aigal Bloom Outbreaks
Along the Western Florida
Coastline
• Coastal Fish Tissue Contaminants
• Wetland Extent, Change, and
Sources of Change
DRINKING WATER
What are the trends in the
quality of drinking water and
their effects on human health?
• Population Served by Com-
munity Water Systems With No
Reported Violations of Health-
Based Standards*
RECREATIONAL WATERS
What are the trends in the con-
dition of recreational waters
and their effects on human
health and the environment?
There are currently no national
indicators available for this topic.
CONSUMABLE FISH AND
SHELLFISH
What are the trends in the con-
dition of consumable fish and
shellfish and their effects on
human health?
• Coastal Fish Tissue
Contaminants*
• Contaminants in Lake Fish
Tissue*
LAND
LAND COVER
What are the trends in land cover
and their effects on human
health and the environment?
• Land Cover*
• Land Cover in the Puget
Sound/ Georgia Basin
• Forest Extent and Type*
This information is distributed solely for the purpose of pre-dsssemination peer review under applicable information quality guidelines. It has
not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Please submit comments at www.regulatiom.gov.
list of Indicators
35
-------
LAND USE
What are the trends in land use
and their effects on human
health and the environment?
• Land Use*
• Urbanization and Population
Change*
WASTES AND THE
ENVIRONMENT
What are the trends in wastes
and their effects on human
health and the environment?
• Quantity of Municipal Solid
Waste Generated and Managed*
• Quantity of RCRA Hazardous
Waste Generated and Managed*
CHEMICALS APPLIED AND
RELEASED TO LAND
What are the trends in chemi-
cals used on the land and their
effects on human health and
the environment?
• Fertilizer Applied for Agricultural
Purposes*
» Toxic Chemicals in Production-
Related Wastes Released, Treated,
Recycled, or Recovered for
Energy Use*
• Pesticide Residues in Food*
• Reported Pesticide Incidents
CONTAMINATED LAND
What are the trends in contam-
inated land and their effects on
human health and the
environment?
• High-Priority Cleanup Sites With
No Human Contact to
Contamination In Excess of
Health-Based Standards*
• High-Priority Cleanup Sites
Where Contaminated Ground
Water Is Not Continuing to
Spread Above Levels of Concern*
HUMAN HEALTH
HEALTH STATUS
What are the trends in human
health status in the United
States?
• General Mortality*
• Life Expectancy at Birth*
• Infant Mortality*
DISEASES AND HEALTH
CONDITIONS
What are the trends in human
disease and conditions for
which environmental pollutants
may be a risk factor, including
across population subgroups
and geographic regions?
• Cancer Incidence*
• Cardiovascular Disease
Prevalence and Mortality*
• Chronic Obstructive Pulmonary
Disease Prevalence and Mortality*
• Asthma Prevalence*
• Infectious Diseases Associated
With Environmental Exposures or
Conditions*
• Childhood Cancer Incidence*
• Birth Defects Rates and
Mortality*
• Low Birthweight*
• Preterm Delivery*
EXPOSURE TO ENVIRONMENTAL
CONTAMINANTS
What are the trends in human
exposure to environmental con-
taminants including across pop-
ulation subgroups and
geographic regions?
• Blood Lead Level*
• Blood Mercury Level*
• Blood Cadmium Level
• Blood Cotinine Level*
• Blood Persistent Organic
Pollutants Level
• Urinary Pesticide Level
• Urinary Phthalate Level
ECOLOGICAL
CONDITION
PATTERNS IN ECOLOGICAL
SYSTEMS
What are the trends in the
extent and distribution of the
nation's ecological systems?
• Forest Extent and Type*
• Forest Fragmentation*
• Ecological Connectivity in EPA
Region 4*
• Relative Ecological Condition
of Undeveloped Land in EPA
Region 5
• Land Cover
• Land Use
• Urbanization and Population
Change
* Wetland Extent, Change, and
Sources of Change
• Land Cover in the Puget
Sound/Georgia Basin
BIOLOGICAL DIVERSITY
What are the trends in the diver-
sity and biological balance of the
nation's ecological systems?
• Bird Populations*
• Fish Faunal Intactness*
« Non-Indigenous Species in the
Estuaries of the Pacific Northwest
• Coastal Benthic Communities
« Harmful Algal Bloom Outbreaks
Along the Western Florida
Coastline
• Submerged Aquatic Vegetation
in the Chesapeake Bay
• Benthic Macroinvertebrates in
Wadeable Streams
ECOLOGICAL PROCESSES
What are the trends in the eco-
logical processes that sustain
the nation's ecological systems?
• Carbon Storage in Forests*
• Ecological Connectivity in EPA
Region 4
PHYSICAL AND CHEMICAL
ATTRIBUTES OF ECOLOGICAL
SYSTEMS
What are the trends in the criti-
cal physical and chemical
attributes and processes of the
nation's ecological systems?
• U.S. and Global Mean
Temperature and Precipitation*
• Sea Surface Temperature
• Sea Level*
• High and Low Stream Flows
• Lake and Stream Acidity
• Nitrogen and Phosphorus
Discharge from Large Rivers
• Nitrogen and Phosphorus in
Streams in Agricultural
Watersheds
* Nitrogen and Phosphorus in
Wadeable Streams
• Streambed Stability in
Wadeable Streams*
• Hypoxia in the Gulf of Mexico
and Long Island Sound
ECOLOGICAL EXPOSURE TO
CONTAMINANTS
What are the trends in biomea-
sures of exposure to common
environmental pollutants in
plants and animals?
• Coastal Fish Tissue
Contaminants*
• Contaminants in Lake Fish
Tissue*
• Ozone Injury to Forest Plants*
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has
not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Please submit comments at www.regulations.gov.
List of Indicators 36
-------
This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not
been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy. Please
submit comments at www.regulations.gov.
------- |