Environmental Encyclopedia

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Environmental Encyclopedia 3

Resistance (inertia)

Chang Jiang (Yangtze River) will displace 1.4 million people

when it is completed; India’s Narmada Valley reservoir will

flood the homes of 1.5 million people. In such cases the

displaced populations must move elsewhere, clearing new

land to reestablish towns and farms. Water loss from evapo-

ration and

seepage

can drastically decrease water volumes

in a river, especially in hot or

arid

regions. Lakes Powell

and Mead on the Colorado River annually lose 1.3 billion

cubic yards (1 billion cubic m) of water through evaporation,

water that both people and natural habitats downstream

sorely need. Egypt’s long and shallow Lake Nasser is even

worse, losing as much as 20 billion cubic yards (15 billion

cubic m) per year. Impounded water also seeps into the

surrounding bedrock, especially in porous sandstone or lime-

stone country. This further decreases river flow and some-

times causes slope instability in the reservoir’s banks. A

disastrous 1963

landslide

in the waterlogged banks of Italy’s

Vaiont reservoir sloshed 192 million cubic yards (300 million

cubic m) of water over the dam and down the river valley,

killing almost 2,500 people in towns downstream. A further

risk arises from the sheer weight of stored water, which

can strain faults deep in the bedrock and occasionally cause

earthquakes.

Sedimentation

is another problem associated with

reservoirs. Free flowing rivers usually carry a great deal of

suspended

sediment

, but the still water of a reservoir allows

these sediments to settle. As they accumulate in the reservoir,

storage capacity decreases. The lake gradually becomes shal-

lower and warmer, with an accompanying decrease in

water

quality

. Even more important, sediment-free water down-

stream of the dam no longer adds sand and mud to river

banks and deltas.

Erosion

of islands, banks, and deltas re-

sults, undermining bridges and walls as well as natural river-

side habitat.

One of the losses felt most acutely by humans is that

of scenic river valleys, gorges, and canyons. China’s Three

Gorges Dam will drown ancient cultural and historic relics

to which travellers have made pilgrimages for centuries. In

the United States, the loss of Utah’s cathedral-like Glen

Canyon and other beautiful or unusual environmental fea-

tures are tragedies that many environmentalists still lament.

See also Arable land; Environmental economics; Environ-

mental policy; Riparian land; River basins

[Mary Ann Cunningham Ph.D.]

ESOURCES

OOKS

Driver, E. E., and W. O. Wunderlich, eds. Environmental Effects of Hydrau-

lic Engineering Works. Proceedings of an International Symposium Held

at Knoxville, Tennessee, Sept. 12-14, 1978. Knoxville: Tennessee Valley

Authority, 1979.

1197

Freeze, R. A., and J. A. Cherry. Groundwater. Englewood Cliffs, NJ:

Prentice-Hall, 1979.

ERIODICALS

Esteva, G., and M. S. Prakash. “Grassroots Resistance to Sustainable Devel-

opment.” The Ecologist 22 (1992): 45–51.

Residence time

Residence time is the length of time that a substance, usually

hazardous material

, can be detected in a given

environ-

ment

. For example, airborne pollutants are carried into the

atmosphere

by natural updrafts. The concentration and

size of the particulates and their residence time exerts varying

degrees of influence on the solar radiation balance. Other

examples include the period of time that oxidant concentra-

tions such as PAN-type or

ozone

remain in the atmosphere,

or the period of time that nuclear by-products are found in

the atmosphere or in the

soil

. See also Hazardous waste

siting; Radioactive waste

Resilience

ecology

, resilience refers to the rate at which a commu-

nity returns to some state of development after it has been

displaced from that state. Ecosystems comprised of commu-

nities with high inherent resilience are, over time, relatively

stable in the face of

environmental stress

. These communi-

ties return to their original structure and functions, or similar

ones, relatively quickly in response to a disturbance. Of

course, there are thresholds for resilience. If a perturbation

is too intense, then the inherent resilience of the community

may be exceeded, and the previous state of ecological devel-

opment may not be rapidly reattained, if at all. Populations

species

that are smaller in size, poor competitors, short-

lived, with short generation times and the ability to spread

quickly are relatively resilient. Those that are larger in size,

competitive, longer-lived, with longer generation times and

high investment in offspring have a higher threshold, or

resistance

, to a stress factor, but have less resilience, and

regenerate more slowly. See also Biosphere; Biotic com-

munity

Resistance (inertia)

ecology

, resistance is the ability of a population or com-

munity to avoid displacement from some state of develop-

ment as a result of an

environmental stress

. Populations

or communities with inherently high resistance are relatively

stable when challenged by such conditions. If the stress is

greater than the population threshold, though, change must

occur.

Environmental Encyclopedia 3

Resource Conservation and Recovery Act

In general,

species

that are larger in size, relatively

competitive, longer-lived, with longer generation times and

high investment in offspring are relatively resistant to inten-

sified stresses. When these species or their communities are

overcome by environmental change, however, they have little

resilience

and tend to recover slowly.

In contrast, species that are smaller in size, short-lived,

highly fecund, and with shorter generation times have little

ability to resist the effects of perturbation. However, these

species and their communities are resilient, and have the

ability to quickly recover from disturbance. This assumes,

of course, that the environmental change has not been too

excessive, and that the

habitat

still remains suitable for

their regeneration and growth. See also Biotic community;

Ecosystem; Population biology

Resource Conservation and Recovery

Act

The Resource Conservation and Recovery Act (RCRA), an

amendment to the

Solid Waste

Disposal Act, was enacted

in 1976 to address a problem of enormous magnitude—how

to safely dispose of the huge volumes of municipal and

industrial solid waste generated nationwide. It is a problem

with roots that go back well before 1976.

There was a time when the amount of waste produced

in the United States was small and its impact on the

environ-

ment

relatively minor. (A river could purify itself every 10

miles [16 km].) However, with the industrial revolution in

the latter part of the nineteenth century, the country began

to grow with unprecedented speed. New products were de-

veloped and consumers were offered an ever-expanding array

of material goods.

This growth continued through the early twentieth

century and took off after World War II when the nation’s

industrial base, strengthened by the war, turned its energies

toward domestic production. The results of this growth were

not all positive. With more goods came more waste, both

hazardous and nonhazardous. In the late 1940s, the United

States was generating roughly 500,000 metric tons of

haz-

ardous waste

a year. In 1985, the

Environmental Protec-

tion Agency

(EPA) estimated that 275 million tons of haz-

ardous waste were generated nationwide.

Waste management

was slow in coming. Much of

the waste produced made its way into the environment where

it began to pose a serious threat to ecological systems and

public health. In the mid-1970s, it became clear, to both

Congress and the nation alike, that action had to be taken

to ensure that solid wastes were managed properly. This

realization began the process that resulted in the passage of

RCRA. The goals set by RCRA were: to protect human

1198

health and the environment; to reduce waste and conserve

energy and

natural resources

; to reduce or eliminate the

generation of hazardous waste as expeditiously as possible.

To achieve these goals, four distinct yet interrelated

programs exist under RCRA. The first program, under Sub-

title D, encourages states to develop comprehensive plans

to manage primarily nonhazardous solid waste, e.g.,

house-

hold waste

. The second program, under Subtitle C, estab-

lishes a system for controlling hazardous waste from the

time it is generated until its ultimate disposal—or from

“cradle-to-grave.” The third program, under Subtitle I, regu-

lates certain underground storage tanks. It establishes per-

formance standards for new tanks and requires leak detec-

tion, prevention and corrective action at underground tank

sites. The newest program to be established is the

medical

waste

program under Subtitle J. It establishes a demonstra-

tion program to track medical waste from generation to

disposal.

Although RCRA created a framework for the proper

management of hazardous and nonhazardous solid waste, it

did not address the problems of hazardous waste encountered

at inactive or abandoned sites or those resulting from spills

that require emergency response. These problems are ad-

dressed by the Comprehensive Environmental Response,

Compensation and Liability Act (CERCLA), commonly

called Superfund.

Today RCRA refers to the overall program resulting

from the Solid Waste Disposal Act. The Solid Waste Dis-

posal Act was enacted in 1965 for the primary purpose of

improving solid waste disposal methods. It was amended in

1970 by the

Resource Recovery

Act and again in 1976 by

RCRA. The changes embodied in RCRA remodeled our

nation’s solid waste management system and added provi-

sions pertaining to hazardous waste management.

The Act continues to evolve as Congress amends it

to reflect changing needs. It has been amended several times

since 1976, most significantly on November 8, 1984. The

1984 amendments, called the Hazardous and Solid Waste

Amendments (HSWA), expanded the scope and require-

ments of RCRA. Provisions resulting from the 1984 amend-

ments are significant, since they tend to deal with the waste

problems resulting from more complex technology.

The Act is a law that describes the kind of waste

management program that Congress wants to establish. This

description is in very broad terms—directing the EPA to

develop and promulgate criteria for identifying the character-

istics of hazardous waste. The Act also provides the Admin-

istrator of the EPA (or designated representative) with the

authority necessary to carry out the intent of the Act—the

authority to conduct inspections.

The Act includes a Congressional mandate for EPA

to develop a comprehensive set of regulations. Regulations

Environmental Encyclopedia 3

Resource Conservation and Recovery Act

are legal mechanisms that define how a statute’s broad policy

directives are to be implemented. RCRA regulations have

been developed by the EPA, covering a range of topics from

guidelines for state solid waste plans to a framework for the

hazardous waste permit program.

RCRA regulations are published according to an es-

tablished process. When a regulation is proposed it is pub-

lished in the Federal Register. It is usually first published as

a proposed regulation, allowing the public to comment on

it for a period of time—normally 30 to 60 days. Included

with the proposed regulation is a discussion of the Agency’s

rationale for the regulatory approach and an explanation, or

preamble, of the technical basis for the proposed regulation.

Following the comment period, EPA evaluates public com-

ments. In addressing the comments, the EPA usually revises

the proposed regulation. The final regulation is published

in the Federal Register ("promulgated"). Regulations are

compiled annually and bound in the Code of Federal Regula-

tions (CFR) according to a highly structured format. The

codified RCRA regulations can be found in Title 40 of the

CFLRL, Parts 240-280; regulations are often cited as 40

CAR.

Although the relationship between an Act and its reg-

ulations is the norm, the relationship between HSWA and

its regulations differs. HSWA is unusual in that Congress

placed explicit requirements in the statute in addition to

instructing the EPA in general language to develop regula-

tions. Many of these requirements are so specific that the

EPA incorporated them directly into the regulations.

HSWA is all the more significant because of the ambitious

schedules that Congress established to implement the Act’s

provisions. Another unique aspect of HSWA is that it estab-

lishes “hammer” provisions—statutory requirements that go

into effect automatically as regulations if EPA fails to issue

these regulations by certain dates. EPA further clarifies its

regulations through guidance documents and policy.

The EPA issues guidance documents primarily to

elaborate and provide direction for implementing the regula-

tions—essentially they explain how to do something. For

example, the regulations in 40 CAR Part 270 detail what is

required in a permit application for a hazardous management

facility. The guidance for this part gives instructions on

how to evaluate a permit application to see if everything is

included. Guidance documents also provide the Agency’s

interpretations of the Act.

Policy statements, however, specify operating proce-

dures that should be followed. They are a mechanism used

by EPA program offices to outline the manner in which

pieces of the RCRA program are to be carried out. In most

cases, policy statements are addressed to staff working on

implementation. Many guidance and policy documents have

been developed to aid in implementing the RCRA Program.

1199

To find out what documents are available, the Office of

Solid Waste’s Directives System lists all RCRA-related pol-

icy guidance and memoranda and identifies where they can

be obtained.

RCRA works as follows: Subtitle D of the Act encour-

ages States to develop and implement solid waste manage-

ment plans. These plans are intended to promote

recycling

of solid wastes and require closing or upgrading of all envi-

ronmentally unsound dumps. Due to increasing volumes,

solid waste management has become a key issue facing many

localities and states. Recognizing this, Congress directed the

EPA in HSWA to take an active role with the states in

solving the difficult problem of solid waste management.

The EPA has been in the process of revising the standards

that apply to

municipal solid waste

landfills. Current with

the revision of these standards, the EPA formed a task force

to analyze solid waste source reduction and recycling options.

The revised solid waste standards, together with the task

force findings, form the basis for the EPA’s development

of strategies to better regulate municipal solid waste man-

agement.

Subtitle C establishes a program to manage hazardous

wastes from “cradle-to-grave.” The objective of the C pro-

gram is to ensure that hazardous waste is handled in a manner

that protects human health and the environment. To this

end, there are Subtitle C regulations regarding the genera-

tion,

transportation

and treatment, storage, or disposal of

hazardous wastes. In practical terms, this means regulating

a large number of hazardous waste handlers. As of June,

1989, the EPA had on record more than 7,000 treatment,

storage and disposal facilities; 17,000 transporters; and about

180,000 large and small quantity generators. By February,

1992, that number had increased substantially (43,000 treat-

ment, storage, and disposal facilities; 19,700 transporters;

238,000 large and small quantity generators).

The Subtitle C program has resulted in perhaps the

most comprehensive regulations the EPA has ever devel-

oped. They first identify those solid wastes that are “hazard-

ous” and then establish various administrative requirements

for the three categories of hazardous waste handlers: genera-

tors, transporters and owners or operators of treatment, stor-

age and disposal facilities (TSDFs). In addition, Subtitle C

regulations set technical standards for the design and safe

operation of TSDFs. These standards are designed to mini-

mize the release of hazardous waste into the environment.

Furthermore, the regulations for TSDFs serve as the basis for

developing and using the permits required for each facility.

Issuing permits is essential to making the Subtitle C regula-

tory program work, since it is through the permitting process

that the EPA or a State actually applies the technical stan-

dards to facilities.

Environmental Encyclopedia 3

Resource recovery

Subtitle I regulates

petroleum

products and hazardous

substances (as defined under Superfund) stored in under-

ground tanks. The objective of Subtitle I is to prevent leakage

groundwater

from tanks and to clean up past releases.

Under Subtitle I, the EPA developed performance standards

for new tanks and regulations for leak detection, prevention,

closure, financial responsibility, and corrective action at all

underground tank sites. This program may be delegated to

states.

Subtitle J was added by Congress when, in the summer

of 1988, medical wastes washed up on Atlantic beaches, thus

highlighting the inadequacy of medical waste management

practices. Subtitle J instructed the EPA to develop a two-

year demonstration program to track medical waste from

generation to disposal in demonstration States. The demon-

stration program was completed in 1991 and Congress has

yet to decide upon the merits of national medical waste

regulation. At this point no Federal regulatory authority is

administering regulations, but individual states are; some are

setting up very stringent regulations on storage, packaging,

transportation, and disposal.

Congress and the President set overall national direc-

tion for RCRA programs. The EPA’s Office of Solid Waste

and Emergency Response translates this direction into op-

erating programs by developing regulations, guidelines and

policy. the EPA then implements RCRA programs or dele-

gates implementation to the states, providing them with

technical and financial assistance.

Waste minimization or reduction is a major EPA goal.

It is defined as any source reduction or recycling activity

that results in either reduction of total volume of hazardous

waste or reduction of toxicity of hazardous waste, or both,

as long as that reduction is consistent with the general goal

of minimizing present and future threats to human health

and the environment. See also Waste reduction

[Liane Clorfene Casten]

ESOURCES

OOKS

Hazardous Waste Management Compliance Handbook. New York: Van Nos-

trand Reinhold, 1992.

RCRA Deskbook. Washington, DC: Environmental Law Institute, 1991.

THER

U. S. Environmental Protection Agency. RCRA Orientation Manual. Wash-

ington, DC: U.S. Government Printing Office, 1990.

Resource recovery

Resource recovery is the process of recovering materials or

energy from

solid waste

for

reuse

. The aim is to make

1200

the best use of the economic, environmental, and social costs

of these materials before they are permanently laid to rest

in a

landfill

. The

Environmental Protection Agency

(EPA) and environmentalists have set up a hierarchy for

resource recovery: reduce first, then reuse, recycle, incinerate

with

energy recovery

, and landfill last. Following the hier-

archy will cut solid waste and reduce resources consumed in

production. Solid waste managers have turned to resource

recovery in an effort to cut disposal costs, and the hierarchy

has become not only an important guideline but a major

inspiration for local

recycling

programs.

After the industrial revolution made a consumer soci-

ety possible,

garbage

was considered a resource for a class

of people who made their living sorting through open dumps,

scavenging for usable items and recovering valuable scrap

metals. Once public health concerns forced cities to institute

garbage collection and dump owners began to worry about

liability for injuries, city dumps were for the most part closed

to the public. Materials recovery continued in the commer-

cial sector, however, with an entire industry growing up

around the capturing of old refrigerators, junk cars, discarded

clothing, and anything else that could be broken down into

its raw materials and made into something else. That indus-

try is still strong; it is represented by powerful trade associa-

tions, and accounts for three-quarters of all ocean-borne

bulk cargo that leaves the Port of New York and New Jersey

for foreign markets.

The Arab

oil embargo

of the 1970s focused attention

on the fact that

natural resources

are limited and can be

made unavailable, and environmentalists took up the cause

of recycling. But only after a barge loaded with New York

City garbage spent months stopping in port after port on

the eastern seaboard because it was unable to find a landfill

was the real problem recognized. There were too few places

to put it. The places that did take garbage often leaked a toxic

brew of leachate and were seldom subject to environmental

requirements.

Environmental restrictions on waste disposal, how-

ever, began to change. The EPA required that landfills be

lined with expensive materials; states began mandating com-

plicated leachate collection systems to protect

ground-

water

. Amendments to the

Clean Air Act

of 1990 changed

the regulations for garbage incinerators and waste-to-energy

plants, which capture the energy created from burning trash

to run turbines or to heat and cool buildings. These facilities

were now required to install

scrubbers

or other devices for

cleaning emissions and to dispose of the ash in safe landfills.

The result of all these changes was a dramatic increase in

the cost of dumping; as the price shot up, municipal leaders

took notice. Economics joined

environmentalism

to sup-

port recycling, and those charged with managing solid wastes

Environmental Encyclopedia 3

Resources for the Future

began to look for ways to get the most out of their trash or

avoid creating it altogether.

Reduction—cutting waste by using less material to

begin with—is at the top of the resource recovery hierarchy

because it eliminates entirely the need for disposal, while

avoiding the environmental costs of using raw materials to

make replacement goods.

Waste reduction

, or source reduc-

tion, requires a change in behavior that many say is unrealistic

when both the culture and the economy in the United States

are based on consumption. However, manufacturers have

responded to consumer demands that products last longer

and use fewer resources. The durability of the average passen-

ger tire, for example, nearly doubled during the 1970s and

1980s. Makers of

disposable diapers

advertise the fact

that they have reduced diaper size so that they take up less

space in landfills.

Reuse also cuts the need for raw materials. Perhaps

the best example is the reusable beverage bottles that were

widely used until the second half of this century. Studies

have shown that reusing a glass bottle takes less energy than

making a new one or melting it down to make a new one.

Recycling has become a popular way to make new use

of the resources in old products. In its purist and most

efficient form, recycling means turning an old object into

the same kind of new object—an old newspaper into a new

one, an old plastic detergent jug into a new one. But new

uses for certain materials are limited, and some laws prevent

recycled plastic from coming into contact with food; in such

cases old items can only be made into lesser products. Recy-

cled plastic soda bottles, for example, can be used in carpet-

ing, television sets, and plastic lumber. The act of recycling

itself also uses energy and causes

pollution

. Materials must

be shipped from drop-off site to the remanufacturer and

then to producer before they can be returned to the retailer.

Grinding plastic into pellets takes energy, and cleaning old

newsprint produces by-products that can pollute water. An-

other drawback to recycling is the unstable price of materials,

which has caused some solid waste managers to reevaluate

local programs.

After

composting

, the resource recovery hierarchy

lists

incineration

with energy recovery. As the last option

before landfilling, incinerators or waste-to-energy plants

only burn what cannot be recycled, and they can recover

one-quarter to one-third of their operating costs by selling

the energy, usually in the form of electricity or steam. But

incineration also produces waste ash, which can contain toxic

materials such as

lead

mercury

. Incinerator ash often

meets EPA standards for hazardous wastes, but because it

mainly comes from household garbage, it is considered non-

hazardous no matter what is detected, although this may

change in the future. Other hazardous materials escape out

the stacks of incinerators in the form of

air pollution

, despite

1201

high-tech scrubbers and other pollution controls. Environ-

mentalists also maintain that the resources used in making

materials that are incinerated are lost, despite the energy

that is produced when they burn. They claim that waste-

to-energy proponents have adopted the term resource recov-

ery for the process in an effort to mask its problems and put

an updated face on an industry that once was unscientific

and uncontrolled.

Last on the list is landfilling. Although the United

States has potential landfill space to last centuries, much of

it is socially or environmentally unsound. Even with exten-

sive liner systems, landfills are expected to leak

chemicals

into groundwater. Most communities, moreover, are unwill-

ing to have new landfills as neighbors, and citizens groups

throughout the country have demonstrated an increasing

ability to keep them out through sophisticated protests.

Finding space for new landfills has become a nightmare for

elected officials and public works managers.

Despite their need for solutions, the resource recovery

hierarchy does not always prove practical for local officials

who are usually faced with tight budgets and the restrictions

of democratic politics. Many of the advantages of the meth-

ods at the top of the hierarchy, such as waste reduction or

recycling, are distant in either time or geography for many

municipalities. A city might be hundreds of miles from the

nearest plant that recycles paper and from the forests that

might benefit from an overall decrease in demand for trees,

for instance. In such a case, recycling paper makes little sense

on a small scale. Environmentalists believe that the solution

is for manufacturers and solid waste managers to make deci-

sions together. Finding the most efficient use of resources

derived from both virgin materials and recovered from wastes

may have to be considered regionally or nationally to be fully

realized. See also Container deposit legislation; Groundwater

pollution; NIMBY; Plastics; Solid waste incineration; Solid

waste volume reduction; Waste stream

[L. Carol Richie]

ESOURCES

OOKS

Brown, L. R., et al. State of the World 1991. New York: W.W. Norton, 1991.

ERIODICALS

Peterson, C. “What Does ‘Waste Reduction’ Mean?” Waste Age (January

1989).

Schall, J. “Does the Hierarchy Make Sense?” MSW Management (January/

February 1993).

Resources for the Future

In 1952 President Harry S. Truman’s Materials Policy Com-

mission, headed by William Paley of the Columbia Broad-

Environmental Encyclopedia 3

Respiration

casting System (CBS), released its final report. The commis-

sion had been asked to examine the status of the nation’s

material resources, such as fuels, metals, and minerals. It

concluded that the country’s material base was in quite good

condition, but the report maintained that further research

was necessary to insure the continued use of these resources.

Paley established Resources for the Future (RFF) as a non-

profit corporation to carry out this research, especially the

updating of resource

statistics

At the same time, the Ford Foundation had created

a fund to support resource

conservation

issues and to orga-

nize a national conference on the issue. Paley allowed this

fund to use the name and facilities of his new corporation,

and RFF hosted the Mid-Century Conference on Resources

for the Future in Washington, D.C. with Ford Foundation

funding.

Perhaps the major result of the conference was organi-

zational. The Ford Foundation decided that RFF should

become the base of its resource research program as an

independent foundation. These organizations began in 1954

with a five-year grant to RFF of $3.4 million “aimed primar-

ily at the economics of the nation’s resource base.” This has

been the goal of research at RFF ever since. Most of the

staff and most of the visiting scholars, as well as most of

the beneficiaries of their small grants program have been

economists, analyzing the importance of material resources

to the United States economy, and examining a wide range

of intertwined economic, resource, conservation, and envi-

ronmental issues.

Resources for the Future is now organized into two

divisions, the Energy and Natural Resources Division, and

the Quality of the Environment Division. There are also

two centers, the National Center for Food and Agricultural

Policy, and the Center for Risk Management. Well-known

experts on resource and environmental issues such as Marion

Clawson, Hans Landsberg, John Krutilla, and Allen Kneese

are long-time staff members or “fellows” of RFF. The orga-

nization also supports resource and environmental research

by non-staff scholars through visiting fellowships and its

small grants program, and the range of these activities ex-

ceeds RFF’s original mandate. RFF publishes an annual

report and a quarterly journal called Resources. The annual

report lists the year’s publications by resident staff, making

it a good reference source for up-to-date materials on a

wide range of resource and environmental issues. Resources

publishes short articles, mostly by staff members or visiting

fellows, and a quarterly report entitled “Inside RFF.”

A scan of these two documents on any given date

reveals the range of RFF interests. A recent annual report

included staff publications on energy on different aspects of

agriculture and agricultural policy, on various aspects con-

necting economics and public

forest management

, on cli-

1202

matic change, on risk management, cost analysis, and regula-

tions and regulatory activities affecting resources and the

environment.

[Gerald L. Young Ph.D.]

ESOURCES

RGANIZATIONS

Resources for the Future, 1616 P Street NW, Washington, DC USA

20036-1400 (202) 328-5000, Fax: (202) 939-3460, <http://www.rff.org>

Respiration

The term respiration has two major definitions. On a cellular

level, respiration is the chemical process by which food mole-

cules are oxidized to release energy. In the process,

carbon

dioxide

and water are also produced. Cellular respiration

is, therefore, the reverse of

photosynthesis

, the process by

which

carbon

dioxide and water are combined to form

complex carbohydrate molecules. On an organismic level,

respiration refers to the act of inhaling and exhaling.

Respi-

ratory diseases

are among the most common of all environ-

mental illnesses. Inhaling

particulate

matter in polluted air

may result, for example, in various forms of pneumoconiosis.

Respiratory diseases

Respiratory diseases—diseases of the lungs and airways such

asthma

, chronic

bronchitis

emphysema

, and lung can-

cer—have diverse causes. While cigarette smoking is the

leading cause of most major respiratory diseases, air pollut-

ants and workplace

toxins

can also contribute to respiratory

illness.

The lungs are equipped with an elaborate defense sys-

tem to repel toxins and invading organisms. Before air

reaches the lungs, it passes through the nose, throat, and

bronchi that are lined with mucus to trap irritants. Within

the bronchi, smaller bronchial tubes and bronchioles are

covered with cilia that sweep particles out. Lungs are far

from vulnerable, however. The defenses can fail, leading to

any number of respiratory diseases.

Cigarette smoking is the most important cause of

Chronic Obstructive Pulmonary Disease (COPD), a name

covering pulmonary emphysema and chronic bronchitis.

These lung diseases damage the air passageways and interfere

with the lung’s ability to function. COPD is the fifth leading

cause of death in the United States, and in a smoking, aging

population, will probably not decline.

Chronic bronchitis is a persistent inflammation of the

bronchial tubes. Mucus cells of the bronchial tree produce

excess mucus, and the lungs may become permanently filled

Environmental Encyclopedia 3

Respiratory diseases

with fluid. Eventually, scar tissue from infection replaces the

cilia, decreasing the lungs’ efficiency. With each infection,

mucus clogs the alveoli, or air sacs. Little or no gas exchange

occurs, and the ventilation-blood flow imbalance reduces

oxygen levels and raises

carbon dioxide

levels in the blood.

Chronic bronchitis usually accompanies the develop-

ment of emphysema. The destruction of too many elastic

fibers in the lungs’ framework and air sac walls results in

hyperinflated air sacs that impair the lungs’ ability to recoil

during expiration. Eventually, the alveoli merge into one

large air sac, and the network of capillaries in the lungs is

lost. This reduces gas exchange that occurs, and stale air is

trapped in the lungs.

These two COPDs are not curable, but can be treated.

Patients can prevent pulmonary infections and the inhalation

of harmful substances, reduce airway obstruction, improve

muscle conditioning and use supplemental oxygen.

Asthma is a disease characterized by a narrowing of

the airways, episodic wheezing, tightness in the chest, short-

ness of breath, and coughing. There are various types of

asthma, including exercise-induced asthma, occupational

asthma triggered by irritants in the workplace, and asthmatic

bronchitis. Trigger factors can include dust, odors, cold air,

sulfur dioxide

fumes, emotional stress, upper-respiratory

infection, exertion, and airborne allergens. Asthma is often

preventable if trigger factors can be identified and elimi-

nated.

Scientists are also turning their attention to health

hazards posed by atmospheric acids and other air pollutants.

One study at 79 southern Ontario hospitals showed a con-

sistent association between the summer levels of atmospheric

sulfates and

ozone

and hospital admissions for acute respira-

tory illnesses such as asthma, chronic bronchitis, and em-

physema.

This “acid air” forms when emissions of sulfur dioxide

and

nitrogen oxides

, mostly from coal-burning

power

plants

and motor vehicles, are transformed to sulfuric and

nitric acids.

Acid aerosol

concentrations tend to be higher

on hot summer days. The fine acid particles can penetrate

the deepest, most delicate tissues of the lungs, inflame respi-

ratory-tract tissue, depress pulmonary function, and constrict

air passages. Health effects are more pronounced when acid

aerosols are accompanied by ozone in the lower

atmo-

sphere

. Together, ozone and acid aerosols produce changes

in the lungs that inhibit their ability to clear themselves of

toxins and other irritants.

High levels of

air pollution

may foster respiratory-

disease symptoms in otherwise healthy individuals. One

study indicates that air

pollution

in Los Angeles may begin

to permanently “derange” an individual’s lung cellular archi-

tecture by age 14. Another study has implicated wood-burn-

ing stoves, which foul the air with tiny particulates that may

1203

cause or exacerbate outbreaks of respiratory illnesses. An

environmental team studying respiratory problems at a Bos-

ton-area high school implicated the school’s poorly designed

ventilation system as the most likely cause of the students’

high rate of respiratory illnesses.

Workplace-related respiratory diseases are on the in-

crease. In 1990, the National Safety Council listed occupa-

tional lung diseases as the leading work-related diseases in

this country. The Chicago-based National Safe Workplace

Institute recently concluded that 2–4% of pulmonary disease

is related to working conditions. Diseases that top the list

include

asbestosis

, lung

cancer

, silicosis, occupational

asthma, and

coal

workers’ pneumoconiosis, commonly

known as

black lung disease

Asbestosis is a chronic fibrotic lung disease caused by

the inhalation of inert dusts. This affliction has received

widespread media coverage because the majority of its vic-

tims have been subjected to long-term exposure to

asbestos

Asbestosis causes a scarring of lung tissue that can result in

serious shortness of breath. Silicosis is a disease of the lungs

caused by breathing in dust that contains silica. Black lung

disease is a long-term lung disease caused by the settlement

of coal dust on the lungs, eventually resulting in emphysema.

Insurance data indicates that people in certain high-

risk occupations, including agriculture, construction, mining,

and quarrying have three to four times the average death

rate for all industries, mostly from respiratory diseases.

Residential homes are also vulnerable.

Chlorine

bleach

and cleaning fluids, insecticides, wood-burning fireplaces,

and gas stoves that produce

nitrogen

dioxide can be toxic

to the lungs. The causes of the expected 170,000 new cases

of lung cancer in 1993 include exposure to

cigarette smoke

ionizing radiation

heavy metals

, and industrial carcino-

gens. See also Air quality; Automobile emissions; Fibrosis;

Respiration; Sick building syndrome; Smog; Smoke; Yok-

kaichi asthma

[Linda Rehkopf]

ESOURCES

OOKS

Haas, F., et al. The Chronic Bronchitis and Emphysema Handbook. New

York: Wiley Science Editions, 1990.

Moeller, D. W. Environmental Health. Cambridge, MA: Harvard Univer-

sity Press, 1992.

ERIODICALS

“Experts Finger Tight Building Syndrome.” Science News 137 (June 9,

1990): 365.

Fackelmann, K. “The High and Low of Respiratory Illness.” Science News

137 (June 9, 1990): 365.

Raloff, J. “Air Pollution: A Respiratory Hue and Cry.” Science News 139

(March 30, 1991): 203.

Environmental Encyclopedia 3

Restoration ecology

Shepherd, S. L., et al. “Is Passive Smoking a Health Threat?” Consumers

Research Magazine 74 (October 1991): 30–1.

Restoration ecology

Ecological restoration is an attempt to reset the ecological

clock and return a damaged

ecosystem

to its predisturbance

state—to turn a disused farm into a

prairie

or to convert a

parcel of low-lying acreage into a vigorous wetland. Precise

replication of the predisturbance condition is unlikely to

occur because each ecosystem is the result of a sequence of

climatic and biological events unrepeatable in precisely the

same order and intensity as the original sequence. However,

close approximations of the predisturbance condition are

often possible, with differences from the original apparent

only to professionals.

Within this limitation, restorationists strive to re-build

ecosystems that, if not exactly like their original predecessors,

possess the qualities of a healthy ecosystem. These properties

include:

dominance of indigenous (native)

species

sustainability or the ability to perpetuate

resistance to invasion by non-native or

pest

species

the presence of healthy functions such as

photosynthesis

respiration

, and plant and animal reproduction.

the ability to generate nutrients such as

nitrogen

and store

them in the ecosystem

a pattern of interaction between key species similar to

the pattern found in undisturbed ecosystems, including

relationships in the food chain

Regrettably, the term restoration as used in the media

and by organizations responsible for ecological damage often

refers to cosmetic activity—the clean up of oil, for instance,

with the expectation that once a substantial amount of spilled

oil has been removed, natural processes will restore the eco-

system to its former condition. Merely re-creating the form

of an ecosystem without attention to whether it is function-

ing is not considered to be true ecological restoration. Devel-

opers also abused the term restoration when acquiring land

for malls or residences in exchange for creating equivalent

or larger

wetlands

elsewhere. Insead of functioning restora-

tions, they often carry out substandard cosmetic restoration

efforts.

Restoration

ecology

developed in the twentieth cen-

tury as a response to

habitat

destruction brought about by

industrialization, overpopulation, and agricultural misman-

agement. Pioneering biologists, such as

Aldo Leopold

, be-

gan to advocate an approach to healing damaged ecosystems

that involved direct human intervention.

Moreover, restoration ecology is more than just applied

science that uses the insights of ecology to build ecosystems.

1204

It is becoming an essential research tool to test the

accuracy

of ecological theories through direct experience. For exam-

ple, the role of fire in the maintenance of prairie ecosystems

has come to be better understood through its application on

restored tracts that were failing to thrive.

As habitat loss accelerates, restoration takes on increas-

ing importance as means of preserving habitat for threatened

species, rekindling lost

biodiversity

, restoring mineral bal-

ance to eroded and infertile lands, improving

water quality

and preserving atmospheric gas balance. The task of restora-

tion, seen as rather abstract in years past, is now viewed

more concretely as the consequences of destruction of habitat

begin to be understood.

Although the specific stages of a restoration project

depend on the initial state of the land and the desired end,

a typical restoration project begins with certain steps to

create the conditions necessary for natural processes to gain

a foothold. On eroded and compacted soils the first step is

often to physically loosen the damaged

soil

by tearing or

furrowing. This promotes water retention and creates suit-

able microenvironments for plant seeds. On depleted land,

it also might be necessary to add

fertilizer

or organic

mulch

to provide initial replenishment of nutrients such as nitrogen

and

phosphorus

Suitable plant seeds, preferably from indigenous spe-

cies, are then introduced. These are usually key varieties

called matrix species. Nurse species that create the conditions

needed to hasten growth of other plants (a process called

facilitation) may be introduced. Sometimes a sequence of

species must be introduced in a specific order. For example,

on clay mining wastes, the best growth is obtained by plant-

ing annual grasses and legumes, then perennial grasses a

year later.

Often animal colonization is left to

nature

, especially

if the site under restoration is near other predisturbance

sites. Management of the site to monitor its progress and

to remove unwanted invading species is usually carried out

in succeeding months and years. If a restoration effort is

successful, the site gradually returns to its natural state and

the need for further intervention decreases.

Ecological restoration requires contributions from a

large number of academic disciplines, although the precise

mixture will vary from one restoration project to another.

The term restoration ecology is misleading in suggesting

that the activity is for ecologists only. All restoration projects

require some degree of funding, and large-scale projects,

such as surface mine

reclamation

or restoration of a wet-

land, river, or lake, may require substantial multi-year fund-

ing. In addition, if the restored ecosystem is to be protected

from further damage, public understanding and support are

necessary. As a consequence, disciplines that study the values

of society and identify those that align with ecological values

Environmental Encyclopedia 3

Retention time

are extremely important for large-scale, long-term successful

restoration efforts.

Equally important is the knowledge obtained from

climatologists, chemists, engineers (where restructuring is

necessary), hydrologists, geologists, statisticians, forestry and

wildlife

specialists, geneticists, soils and

sediment

chemists,

political scientists, attorneys, and a variety of other profes-

sions. Historians and anthropologists often have a crucial

role in restoration because the history of ecological damage

may be reconstructed with historic evidence, both written

and through cultural and biological artifacts and relics.

The role of private citizens in a restoration effort often

is pivotal. Community leaders may provide funds toward

carrying out restoration, while the work of local volunteers

helps to connect the community with the organizations and

institutions administering a project. Community involve-

ment also provides a project with a long-term focus months

or years after the initial effort is complete. Moreover, the

labor-intensive task of restoration seems to thrive when it is

carried out by volunteers and concerned individuals working

together with specialists.

Although underlying theory in the field of restoration

ecology is still in its infancy and the precise outcome of a

project is almost always uncertain, restoration efforts virtually

all result in improvement to damaged environments. The

condition of a restored system may be strikingly superior to

the damaged condition. For example, the tidal Thames River

in England had virtually no fish species in the 1950s. How-

ever, many years after

pollution

clean up and restoration,

over 100 species were found in the tidal area. In the United

States,

Lake Washington

in the Pacific Northwest, the

Kissimmee River in Florida, the Rio Blanco in Colorado,

and the Hackensack River Meadowlands in the New York

metropolitan area are examples of successful ecological pollu-

tion clean-ups and restoration. Many of these efforts were

citizen-initiated.

The United States Department of Agriculture

Fish

and Wildlife Service

(USFWS) has undertaken a new ap-

proach to restoring waterways, lakes, and wetlands looking

at the processes that impact these ecosystems from a larger

watershed

perspective. Identifying sources of pollution and

environmental stress

at the level of the watershed allows

scientists to incorporate study of the surrounding land and

its effects on habitat destruction in the at risk body of water.

An example where watershed analysis sucessfully provided

the necessary information for ecological restoration is in the

restoration of stream corridors in the Whitefish Mountains

of Montana.

Another success story is the restoration of the Lanph-

ere

Dunes

Unit of the Humboldt Bay

National Wildlife

Refuge

the Nature Conservancy

and its partners. The

major challenge in the Lanphere Dunes was eradication of

1205

a 10-acre (4-ha) patch of non-native invasive grass called

European beachgrass (Ammophila arenaria). European

beachgrass is destructive to dunes because it changes that

way that sand accumulates. This alters the suitability of the

habitat for native plants. The elimination of the non-native

grass and restoration of native plant communities was ac-

complished with more than 2,000 person hours per acre of

volunteer labor over the course of three years. As of 1997,

native plant cover had increased by almost 50%.

Similar international restorations, such as the Guana-

caste dry forest in Costa Rica, show that citizens of devel-

oping countries with far fewer monetary resources the United

States can also have strong involvement in ecological restora-

tion. In a time of environmental attrition, the restoration

movement plays a role in shaping the future by helping

citizens develop a feeling of connection between themselves

and their wild lands, while providing concrete improvements

in ecological conditions.

[John Cairns Jr. and Jeffrey Muhr and Marie H. Bundy]

ESOURCES

OOKS

Berger, J. J., ed. Environmental Restoration: Science and Strategies for Restor-

ing the Earth. Covelo, CA: Island Press, 1989.

Bradshaw, A. D., and M. J. Chadwick. The Restoration of Land. Berkeley:

University of California Press, 1980.

Cairns Jr., J. Rehabilitating Damaged Ecosystems. 2 vols. Boca Raton: CRC

Press, 1988.

Ehrlich, P. R., and A. H. Ehrlich. Healing the Planet. New York: Addison-

Wesley, 1991.

Jordan III, W. R., et al., eds. Restoration Ecology: A Synthetic Approach to

Ecological Research. Cambridge: Cambridge University Press, 1990.

National Research Council. Restoration of Aquatic Ecosystems: Science, Tech-

nology, and Public Policy. Washington, DC: National Academy Press, 1991.

ERIODICALS

Burke, William K. “Return of the Native: The Art and Science of Environ-

mental Restoration.” E Magazine, July/August 1992.

Retention time

Retention time refers to a time frame in which

chemicals

stay in a certain location. The term is sometimes used inter-

changeably with residence or renewal time, which in

limnol-

ogy

(aquatic

ecology

) describes the length of time a water

molecule or a chemical resides in a body of water. The

residence time

of water is called the hydraulic retention

time. It may range from days to hundreds of years, depending

on the volume of the lake and rates of inflow and outflow,

and is often used in calculations of

nutrient loading

. Reten-

tion time can also refer to the length of time needed to

detoxify harmful substances or to break down hazardous

chemicals in pharmaceutical and

sewage treatment

plants;

Environmental Encyclopedia 3

Reuse

the length of time chemicals stay in a living organism; or

the length of time needed to detect certain chemicals by

instruments such as gas

chromatography

Reuse

Reuse, using a product more than once in its original form, is

one of the preferred methods of solid

waste management

because it prevents materials from becoming part of the

waste stream

. It is a form of source reduction of waste.

Some products are specifically designed to be reusable

while others are commonly reused as a matter of convenience.

In the former instance, products such as canvas shopping

bags and cloth napkins are meant to be used again and again,

unlike their paper cousins. In the latter case, glass and plastic

food containers are often reused for numerous household

purposes, even though they are intended to be used only as

food packaging.

Reuse of products is a basic component of diaper ser-

vices and home bottled water delivery. Although neither of

these services were originally created with

waste reduction

in mind, they do impact

solid waste

generation. A cotton

diaper can be used 70 or more times, unlike a single-use

disposable diaper. The three and five gallon bottles used by

most bottled water services are picked up and taken back

to the water plant for refilling, eliminating the need for

consumers to buy individual gallon containers in super-

markets.

Deposit systems for beer and soft drink containers

represent another form of product reuse. In these systems,

consumers pay a nominal fee when they purchase beverages

sold in specific types of containers. The fee is refunded when

they return the empty containers to the retailer or other

designated location. Virtually all beer and soft drinks used

to be sold in returnable bottles. During the 1950s, the use

of nonreturnable bottles and metal cans started to be more

commonplace. By the mid-1980s, most beverages were pack-

aged in nonreturnable bottles, cans, or plastic containers.

Nine states currently have legislation requiring depos-

its on beverage containers. The deposits are meant to be

incentives to consumers to return the bottles. Where such

legislation exists, between 70 and 90% of the targeted con-

tainers are returned. Litter control rather than solid waste

reduction is sometimes the purpose of beverage

container

deposit legislation

. Reduction in litter has been docu-

mented to be as high as 80%, but the impact on solid waste

disposal is more difficult to calculate since beverage contain-

ers account for a relatively small portion of the waste stream.

Another type of product reuse is resale of used clothing

and household items through thrift stores and garage sales.

Although calculating the impact of such practices on waste

1206

generation would be extremely difficult, there is no doubt

that they result in some reduction in waste disposal. See also

Recyclables; Recycling; Waste reduction

[Teresa C. Donkin]

ESOURCES

OOKS

Bohm, P. Deposit-Refund Systems: Theory and Applications to Environmental,

Conservation and Consumer Policy. Baltimore: Johns Hopkins University

Press, 1981.

Revegetation

see

Restoration ecology

Rhinoceroses

Popularly called rhinos, rhinoceroses are heavily-built, thick-

skinned herbivores with one or two horns on their snout

and three toes on their feet. The family Rhinocerotidae

includes five

species

found in Asia and Africa, all of which

face

extinction

The two-ton, one-horned Great Indian rhinoceroses

(Rhinoceros unicornis) are shy and inoffensive animals that

seldom act aggressively. These rhinos were once abundant

in Pakistan, northern India, Nepal, Bangladesh, and Bhutan.

Today, there are about 2,400 Great Indian rhinos left in

two game reserves in Assam, India, and in Nepal. The

smaller one-horned Javan rhinoceros (Rhinoceros sondaicus)

is the only species in which the females are hornless. Once

ranging throughout southeast Asia, Javan rhinos are now on

the verge of extinction, with only 60 living on reserves in

Java and Vietnam.

The Sumatran rhinoceros (Didermocerus sumatrensis),

the smallest of the rhino family, has two horns and a hairy

hide. There are two subspecies—D. s. sumatrensis (found in

Sumatra and Borneo) and D. s. lasiotis—found in Thailand,

Malaysia, and Burma. Sumatran rhinos are found in hilly

jungle terrain and once coexisted in southeast Asia with

Javan rhinos. Now there are only 300 Sumatran rhinos left.

The two-horned, white, or square-lipped, rhinoceros

(Ceratotherium simum) of the African

savanna

is the largest

land mammal after the African elephant, standing 7 ft (2

m) at the shoulder and weighing more than 3 tons. White

rhinos have a wide upper lip for grazing. There are two

subspecies: the northern white (C. s. cottoni) and the southern

white (C. s. simum). Once common in the Sudan, Uganda,

and Zaire, northern white rhinos are now extremely rare,

with only 40 left (28 in Zaire, the rest in zoos). Southern

African white rhinos are faring somewhat better (7,500) and

are the world’s most common rhino.