Environmental Encyclopedia

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Environmental Encyclopedia 3

Agent Orange

placed on the Superfund’s

National Priorities List

for clean

up. ATSDR has preformed 951 health assessments in the

two years after the law was passed. Approximately one quar-

ter of these assessments were memos or reports that had

been completed prior to 1986 and were simply re-labeled

as health assessments.

These first assessments have been harshly criticized.

The General Accounting Office (GAO), a congressional

agency that reviews the actions of the federal administration,

charged that most of these assessments were inadequate.

Some argued that the agency was underfunded and poorly

organized. Recently, ATSDR received less than 5% of the

$1.6 billion appropriated for the Superfund project.

Subsequent health assessments, more than 200 of

them, have generally been more complete, but they still may

not be adequate in informing the community and the EPA

of the dangers at specific sites. In general, ATSDR identifies

a local agency to help prepare the health surveys. Unlike

many of the first assessments, more recent surveys now in-

clude site visits and face-to-face interviews. However, other

data on environmental effects are limited. ATSDR only

considers environmental information provided by the com-

panies that created the hazard or data collected by the EPA.

In addition, ATSDR only assesses health risks from illegal

emissions, not from “permitted” emissions. Some scientists

contend that not enough is known about the health effects of

exposure to hazardous substances to make conclusive health

assessments.

Reaction to the performance of ATSDR’s other func-

tions has been generally more positive. As mandated by

SARA, ATSDR and the EPA have prepared hundreds of

toxicological profiles of hazardous substances. These profiles

have been judged generally helpful, and the GAO praised

ATSDR’s registry of people who have been exposed to toxic

substances.

[Alair MacLean]

ESOURCES

OOKS

Environmental Epidemiology: Public Health and Hazardous Wastes. National

Research Council. Committee on Environmental Epidemiology. Washing-

ton, DC: National Academy Press, 1991.

Lewis, S., B. Keating, and D. Russell. Inconclusive by Design: Waste, Fraud

and Abuse in Federal Environmental Health Research. Boston: National Tox-

ics Campaign Fund; and Harvey, LA: Environmental Health Network,

1992.

THER

Superfund: Public Health Assessments Incomplete and of Questionable Value.

Washington, DC: General Accounting Office, 1991.

RGANIZATIONS

The ATSDR Information Center, , (404) 498-0110, Fax: (404) 498-0057,

Toll Free: (888) 422-8737, Email: ATSDRIC@cdc.gov, <http://

www.atsdr.cdc.gov>

Agent Orange

Agent Orange is a

herbicide

recognized for its use during

the Vietnam War. It is composed of equal parts of two

chemicals

2,4-D

and

2,4,5-T

. A less potent form of the

herbicide has also been used for clearing heavy growth on

a commercial basis for a number of years. However, it does

not contain 2,4-D. On a commercial level, the herbicide

was used in forestry control as early as the 1930s. In the

1950s through the 1960s, Agent Orange was also exported.

For example, New Brunswick, Canada, was the scene of

major Agent Orange spraying to control forests for industrial

development. In Malaysia in the 1950s, the British used

compounds with the chemical mixture 2,4,5-T to clear com-

munication routes.

In the United States, herbicides were considered for

military use towards the end of World War II, during the

action in the Pacific. However, the first American military

field tests were actually conducted in Puerto Rico, Texas,

and Fort Drum, New York, in 1959.

That same year—1959—the Crops Division at Fort

Detrick, Maryland initiated the first large-scale military

de-

foliation

effort. The project involved the aerial application

of Agent Orange to about 4 mi

(10.4 km

) of vegetation.

The experiment proved highly successful; the military had

found an effective tool. By 1960, the South Vietnamese

government, aware of these early experiments, had requested

that the United States conduct trials of these herbicides for

use against guerrilla forces. Spraying of Agent Orange in

Southeast Asia began in 1961. South Vietnam President

Diem stated that he wanted this “powder” in order to destroy

the rice and the food crops that would be used by the Viet

Cong. Thus began the use of herbicides as a weapon of war.

The United States military became involved, recogniz-

ing the limitations of fighting in foreign territory with troops

that were not accustomed to jungle conditions. The military

wanted to clear communication lines and open up areas of

visibility

in order to enhance their opportunities for success.

Eventually, the United States military took complete control

of the spray missions. Initially, there were to be restrictions:

the spraying was to be limited to clearing power lines and

roadsides, railroads and other lines of communications and

areas adjacent to depots. Eventually, the spraying was used to

defoliate the thick jungle brush, thereby obliterating enemy

hiding places.

Once under the authority of the military, and with no

checks or restraints, the spraying continued to increase in

Environmental Encyclopedia 3

Agent Orange

Deforestation of the Viet Cong jungle in South Vietnam. (AP/Wide World Photos. Reproduced by permission.)

intensity and abandon, escalating in scope because of military

pressure. It was eventually used to destroy crops, mainly rice,

in an effort to deprive the enemy of food. Unfortunately,

the civilian population—Vietnamese men, women, and chil-

dren—was also affected. The United States military sprayed

3.6 million acres (1.5 million ha) with 19 million gal (720

million l) of Agent Orange over nine years.

The spraying also became useful in clearing military

base perimeters, cache sites, and waterways. Base perimeters

were often sprayed more than once. In the case of dense

jungle growth, one application of spray was made for the

upper and another for the lower layers of vegetation. Inland

forests, mangrove forests, and cultivated lands were all tar-

gets. Through Project Ranch Hand—the Air Force team

assigned to the spray missions—Agent Orange became the

most widely produced and dispensed defoliant in Vietnam.

Military requirements for herbicide use were devel-

oped by the Army’s Chemical Operations Division, J-3,

Military Assistance Command, Vietnam, (MACV). With

Project Ranch Hand underway, the spray missions increased

monthly after 1962. This increase was made possible by the

continued military promises to stay away from the civilians

or to re-settle those civilians and re-supply the food in any

areas where herbicides destroyed the food of the innocent.

These promises were never kept. The use of herbicides for

crop destruction peaked in 1965 when 45% of the total

spraying was designed to destroy crops.

Initially, the aerial spraying took place near Saigon.

Eventually the geographical base was widened. During the

1967 expansion period of herbicide procurement, when re-

quirements had become greater than the industries’ ability

to produce, the Air Force and Joint Chiefs of Staff become

actively involved in the herbicide program. All production

for commercial use was diverted to the military, and the

Department of Defense (DOD) was appointed to deal with

problems of procurement and production. Commercial pro-

ducers were encouraged to expand their facilities and build

new plants, and the DOD made attractive offers to compa-

nies that might be induced to manufacture herbicides. A

number of companies were awarded contracts. Working

closely with the military, certain chemical companies sent

technical advisors to Vietnam to instruct personnel on the

methods and techniques necessary for effective use of the

herbicides.

Environmental Encyclopedia 3

Agent Orange

During the peak of the spraying, approximately 129

sorties were flown per aircraft. Twenty-four UC-123B air-

craft were used, averaging 39 sorties per day. In addition,

there were trucks and helicopters that went on spraying

missions, backed up by such countries as

Australia

. C-123

cargo planes and helicopters were also used. Helicopters flew

without cargo doors so that frequent ground fire could be

returned. But the rotary blades would kick up gusts of spray,

thereby delivering a powerful dose onto the faces and bodies

of the men inside the plane.

The dense Vietnamese jungle growth required two

applications to defoliate both upper and lower layers of vege-

tation. On the ground, both enemy troops and Vietnamese

civilians came in contact with the defoliant. American troops

were also exposed. They could inhale the fine misty spray

or be splashed in the sudden and unexpected deluge of

an emergency dumping. Readily absorbing the chemicals

through their skin and lungs, hundreds of thousands of

United States military troops were exposed as they lived on

the sprayed bases, slept near empty drums, and drank and

washed in water in areas where defoliation had occurred.

They ate food that had been brushed with spray. Empty

herbicide drums were indiscriminately used and improperly

stored. Volatile fumes from these drums caused damage to

shade trees and to anyone near the fumes. Those handling

the herbicides in support of a particular project goal had the

unfortunate opportunity of becoming directly exposed on

a consistent basis. Nearly three million veterans served in

Southeast Asia. There is growing speculation that nearly

everyone who was in Vietnam was eventually exposed to

some degree—far less a possibility for those stationed in

urban centers or on the waters.

According to official sources, in addition to the Ranch

Hand group at least three groups were exposed:

A group considered secondary support personnel. This in-

cluded Army pilots who may have been involved in helicop-

ter spraying, along with the Navy and Marine pilots.

Those who transported the herbicide to Saigon, and from

there to Bien Hoa and Da Nang. Such personnel trans-

ported the herbicide in the omnipresent 55-gallon (208-

l) containers.

Specialized mechanics, electricians, and technical person-

nel assigned to work on various aircraft. Many of this group

were not specifically assigned to Ranch Hand but had to

work in aircraft that were repeatedly contaminated.

Agent Orange was used in Vietnam in undiluted form

at the rate of 3–4 gal (11.4-15.2 l) per acre. 13.8 lb (6.27

kg) of the chemical 2,4,5-T were added to 12 lb (5.5 kg)

of 2,4-D per acre, a nearly 50-50 ratio. This intensity is

13.3 lb (6.06 kg) per acre more than was recommended

by the military’s own manual. Computer tapes (HERBS

TAPES) now available show that some areas were sprayed

as much as 25 times in just a few short months, thereby

dramatically increasing the exposure to anyone within those

sprayed areas. Between 1962 and 1971 an estimated 11.2

million gal (42.4 million l) of Agent Orange were dumped

over South Vietnam.

Evaluations show that the chemical had killed and

defoliated 90–95% of the treated vegetation. Thirty-six per-

cent of all mangrove forest areas in South Vietnam were

destroyed. Viet Cong tunnel openings, caves, and above

ground shelters were revealed to the aircraft after the herbi-

cides were shipped in drums identified by an orange stripe

and a contract identification number that enabled the gov-

ernment to identify the specific manufacturer. The drums

were sent to a number of central

transportation

points for

shipment to Vietnam.

Agent Orange is contaminated by the chemical

di-

oxin

, specifically TCDD. In Vietnam, the dioxin concentra-

tion in Agent Orange varied from

parts per billion

(ppb) to

parts per million

(ppm), depending on each manufacturer’s

production methods. The highest reported concentration in

Agent Orange was 45 ppm. The

Environmental Protection

Agency

(EPA) evacuated

Times Beach

, Missouri, when

tests revealed

soil

samples there with two parts per billion

of dioxin. The EPA has stated that one ppb is dangerous

to humans.

Ten years after the spraying ended, the agricultural

areas remained barren. Damaging amounts of dioxin stayed

in the soil thus infecting the food chain and exposing the

Vietnamese people. As a result there is some concern that

the high levels of TCDD are responsible for infant

mortal-

ity

birth defects

, and spontaneous abortions that occur in

higher numbers in the once sprayed areas of Vietnam. An-

other report indicates that thirty years after Agent Orange

contaminated the area, there is 100 times as much dioxin

found in the bloodstream of people living in the area than

those living in non-contaminated areas of Vietnam. This is

a result of the dioxin found in the soil of the once heavily

sprayed land. The chemical is then passed on to humans

through the food they eat. Consequently, dioxin is also

spread to infants through the mother’s breast milk, which

will undoubtedly affect the child’s development.

In 1991 Congress passed the Agent Orange Act(-

Public Law 102-4), which funded the extensive scientific

study of the long-term health effects of Agent Orange and

other herbicides used in Vietnam. As of early 2002, Agent

Orange had been linked to the development of peripheral

neuropathy, type II diabetes, prostate

cancer

, multiple my-

eloma, lymphomas, soft tissue sarcomas, and respiratory can-

cers. Researchers have also found a possible correlation be-

tween dioxin and the development of spinal bifida, a birth

defect, and childhood

leukemia

in offspring of exposed

vets. It is important to acknowledge the

statistics

do not

Environmental Encyclopedia 3

Agglomeration

necessarily show a strong link between exposure to Agent

Orange or TCDD and some of the conditions listed above.

However, Vietnam veterans who were honorably discharged

and have any of these “presumptive” conditions (i.e., condi-

tions presumed caused by wartime exposure) are entitled

to Veterans Administration (VA) health care benefits and

disability compensation under federal law. Unfortunately

many Vietnamese civilians will not receive any benefits de-

spite the evidence that they continue to suffer from the

affects of Agent Orange.

[Liane Clorfene Casten and Paula Anne Ford-Martin]

ESOURCES

OOKS

Committee to Review the Health Effects in Vietnam Veterans of Exposure

to Herbicides, Division of Health Promotion and Disease Prevention,

Institute of Medicine. Veterans and Agent Orange: Update 2000.Washington,

DC: National Academy Press, 2001.

ERIODICALS

“Agent Orange Exposure Linked to Type 2 Diabetes.” Nation’s Health 30,

no. 11 (December 2000/January 2001): 11.

“Agent Orange Victims.” Earth Island Journal 17, no. 1 (Spring 2002): 15.

Dreyfus, Robert. “Apocolypse Still.” Mother Jones (January/February 2000).

Korn, Peter."The Persisting Poison; Agent Orange in Vietnam.” The Nation

252, no.13 (April 8, 1991): 440.

Young, Emma"Foul Fare.” New Scientist 170, no. 2292 (May 26, 2001): 13.

THER

U.S. Veterans Affairs (VA). Agent Orange [June 2002]. <http://www.va.gov/

agentorange>.

Agglomeration

Any process by which a group of individual particles is

clumped together into a single mass. The term has a number

of specialized uses. Some types of rocks are formed by the

agglomeration of particles of sand, clay, or some other mate-

rial. In geology, an agglomerate is a rock composed of volca-

nic fragments. One technique for dealing with

air pollution

is ultrasonic agglomeration. A source of very high frequency

sound is attached to a smokestack, and the ultrasound pro-

duced by this source causes tiny

particulate

matter in waste

gases to agglomerate into particles large enough to be col-

lected.

Agricultural chemicals

The term agricultural chemical refers to any substance in-

volved in the growth or utilization of any plant or animal

of economic importance to humans. An agricultural chemical

may be a natural product, such as urea, or a synthetic chemi-

cal, such as DDT. The agricultural

chemicals

now in use

include fertilizers, pesticides, growth regulators, animal feed

supplements, and raw materials for use in chemical processes.

In the broadest sense, agricultural chemicals can be

divided into two large categories, those that promote the

growth of a plant or animal and those that protect plants

or animals. To the first group belong plant fertilizers and

animal food supplements, and to the latter group belong

pesticides, herbicides, animal vaccines, and antibiotics.

In order to stay healthy and grow normally, crops

require a number of nutrients, some in relatively large quanti-

ties called macronutrients, and others in relatively small

quantities called micronutrients.

Nitrogen

phosphorus

and potassium are considered macronutrients, and boron,

calcium,

chlorine

copper

, iron, magnesium, manganese

among others are micronutrients.

Farmers have long understood the importance of re-

plenishing the

soil

, and they have traditionally done so by

natural means, using such materials as manure, dead fish,

or compost. Synthetic fertilizers were first available in the

early twentieth century, but they became widely used only

after World War II. By 1990 farmers in the United States

were using about 20 million tons (20.4 million metric tons)

of these fertilizers a year.

Synthetic fertilizers are designed to provide either a

single

nutrient

or some combination of nutrients. Examples

of single-component or “straight” fertilizers are urea

(NH

CONH

), which supplies nitrogen, or potassium chlo-

ride (KCl), which supplies potassium. The composition of

“mixed” fertilizers, those containing more than one nutrient,

is indicated by the analysis printed on their container. An

8-10-12

fertilizer

, for example, contains 8% nitrogen by

weight, 10% phosphorus, and 12% potassium.

Synthetic fertilizers can be designed to release nutri-

ents almost immediately ("quick-acting") or over longer peri-

ods of time ("time-release"). They may also contain specific

amounts of one or more trace nutrients needed for particular

types of crops or soil. Controlling micronutrients is one of

the most important problems in fertilizer compounding and

use; the presence of low concentrations of some elements

can be critical to a plant’s health, while higher levels can

be toxic to the same plants or to animals that ingest the

micronutrient.

Plant growth patterns can also be influenced by direct

application of certain chemicals. For example, the gibberel-

lins are a class of compounds that can dramatically affect

the rate at which plants grow and fruits and vegetables ripen.

They have been used for a variety of purposes ranging from

the hastening of root development to the delay of fruit

ripening. Delaying ripening is most important for marketing

agricultural products because it extends the time a crop can

be transported and stored on grocery shelves. Other kinds

of chemicals used in the processing, transporting, and storage

Environmental Encyclopedia 3

Agricultural environmental management

of fruits and vegetables include those that slow down or speed

up ripening (maleic hydrazide, ethylene oxide, potassium

permanganate, ethylene, and acetylene are examples), that

reduce weight loss (chlorophenoxyacetic

acid

, for example),

retain green color (cycloheximide), and control firmness

(ethylene oxide).

The term agricultural chemical is most likely to bring

to mind the range of chemicals used to protect plants against

competing organisms: pesticides and herbicides. These

chemicals disable or kill bacteria,

fungi

, rodents, worms,

snails and slugs, insects, mites, algae, termites, or any other

species

of plant or animal that feeds upon, competes with,

or otherwise interferes with the growth of crops. Such chemi-

cals are named according to the organism against which they

are designed to act. Some examples are fungicides (designed

to kill fungi), insecticides (used against insects), nematicides

(to kill round worms), avicides (to control birds), and herbi-

cides (to combat plants). In 1990, 393 million tons of herbi-

cides, 64 million tons of insecticides, and 8 million tons of

other pesticides were used on American farmlands.

The introduction of synthetic pesticides in the years

following World War II produced spectacular benefits for

farmers. More than 50 major new products appeared be-

tween 1947 and 1967, resulting in yield increases in the

United States ranging from 400% for corn to 150% for

sorghum and 100% for wheat and soybeans. Similar increases

less developed countries

, resulting from the use of both

synthetic fertilizers and pesticides, eventually became known

as the Green Revolution.

By the 1970s, however, the environmental conse-

quences of using synthetic pesticides became obvious.

Chemicals were becoming less effective as pests developed

resistances to them, and their toxic effects on other organisms

had grown more apparent. Farmers were also discovering

drawbacks to chemical fertilizers as they found that they had

to use larger and larger quantities each year in order to

maintain crop yields. One solution to the environmental

hazards posed by synthetic pesticides is the use of natural

chemicals such as juvenile hormones, sex attractants, and

anti-feedant compounds. The development of such natural

pest-control materials has, however, been relatively modest;

the vast majority of agricultural companies and individual

farmers continue to use synthetic chemicals that have served

them so well for over a half century.

Chemicals are also used to maintain and protect live-

stock. At one time, farm animals were fed almost exclusively

on readily available natural foods. They grazed on

range-

lands

or were fed hay or other grasses. Today, carefully

blended chemical supplements are commonly added to the

diet of most farm animals. These supplements have been

determined on the basis of extensive studies of the nutrients

that contribute to the growth or milk production of cows,

sheep, goats, and other types of livestock. A typical animal

supplement diet consists of various vitamins, minerals, amino

acids, and nonprotein (simple) nitrogen compounds. The

precise formulation depends primarily on the species; a vita-

min supplement for cattle, for example, tends to include A,

D, and E, while swine and poultry diets would also contain

Vitamin K, riboflavin, niacin, pantothenic acid, and choline.

A number of chemicals added to animal feed serve no

nutritional purpose but provide other benefits. For example,

the addition of certain hormones to the feed of dairy cows

can significantly increase their output of milk.

Genetic engi-

neering

is also becoming increasingly important in the mod-

ification of crops and livestock. Cows injected with a geneti-

cally modified chemical, bovine somatotropin, produce a

significantly larger quantity of milk.

It is estimated that infectious diseases cause the death

of 15–20 of all farm animals each year. Just as plants are

protected from pests by pesticides, so livestock are protected

from disease organisms by immunization, antibiotics, and

other techniques. Animals are vaccinated against species-

specific diseases, and farmers administer antibiotics, sulfon-

amides, nitrofurans, arsenicals, and other chemicals that pro-

tect against disease-causing organisms.

The use of chemicals with livestock can have deleteri-

ous effects, just as crop chemicals have. In the 1960s, for

example, the hormone diethylstilbestrol (DES) was widely

used to stimulate the growth of cattle, but scientists found

that detectable residues of the hormone remained in meat

sold from the slaughtered animals. DES is now considered

carcinogen

, and the U.S.

Food and Drug Administration

has banned its use in cattle feed since 1979.

[David E. Newton]

ESOURCES

OOKS

Benning, L. E. Beneath the Bottom Line: Agricultural Approaches to Reduce

Agrichemical Contamination of Groundwater. Washington, DC: Office of

Technology Assessment, 1990.

———, and J. H. Montgomery. Agrochemicals Desk Reference: Environmen-

tal Data. Boca Raton, FL: Lewis, 1993.

———, and T. E. Waddell. Managing Agricultural Chemicals in the Envi-

ronment: The Case for a Multimedia Approach. Washington, DC: Conserva-

tion Foundation, 1988.

Chemistry and the Food System, A Study by the Committee on Chemistry and

Public Affairs of the American Chemical Society. Washington, DC: American

Chemical Society, 1980.

Agricultural environmental

management

The complex interaction of agriculture and

environment

has been an issue since the beginning of man. Humans grow

Environmental Encyclopedia 3

Agricultural environmental management

food to eat and also hunt animals that depend on natural

resources for healthy ongoing habitats. Therefore, the

world’s human population must balance farming activities

with maintaining natural resources. The term agriculture

originally meant the act of cultivating fields or growing crops.

However, it has expanded to include raising livestock as well.

When early settlers began farming and ranching in

the United States, they faced pristine wilderness and open

prairies. There was little cause for concern about protecting

the environment or population and for two centuries, the

country’s land and water were aggressively used to create a

healthy supply of ample food for Americans. In fact, many

American families settled in rural areas and made a living

as farmers and ranchers, passing the family business down

through generations. By the 1930s, the federal government

began requiring farmers to idle certain acres of land to pre-

vent oversupply of food and to protect exhausted

soil

Since that time, agriculture has become a complex

science, as farmers must carefully manage soil and water to

lessen risk of degrading the soil and its surrounding environ-

ment or depleting water tables beneath the land’s surface.

In fact, farming and ranching present several environmental

challenges that require careful management by farmers and

local and federal regulatory agencies that guide their activi-

ties. The science of applying principles of ecology to agricul-

ture is called

agroecology

. Those involved in agroecology

develop farming methods that use fewer synthetic (man-

made) pesticides and fertilizers and encourage organic farm-

ing. They also work to conserve energy and water.

Soil

erosion

, converting land to agricultural use, intro-

duction of

fertilizer

and pesticides, animal wastes, and irri-

gation are parts of farming that can lead to changes in quality

or availability of water. An expanding human population

has lead to increased farming and accelerated soil erosion.

When soil has a low capacity to retain water, farmers must

pump

groundwater

up and spray it over crops. After years

of doing so, the local water table will eventually fall. This

can impact native vegetation in the area.

The industry calls the balance of environment and

lessening of agricultural effects sustainability or

sustainable

development

. In some parts of the world, like in the High

Plains of the United States or parts of Saudi Arabia, popula-

tions and agriculture are depleting water aquifers faster than

the natural environment can replenish them. Sustainable

development involves dedicated, scientifically based plans to

ensure that agricultural activity is managed in such a way

that aquifers are not prematurely depleted.

Agroforestry

is a method of cultivating both crops

and teres on the same land. Between rows of trees, farmers

plant agricultural crops that generate income during the time

it takes the trees to grow mature enough to produce earnings

from nuts or lumber.

Increased modernization of agriculture also impacts

the environment. Traditional farming practice, which con-

tinues in underdeveloped countries today, consists of subsis-

tence agriculture. In subsistence farming, just enough crops

and livestock are raised to meet the needs of a particular

family. However, today large farms produce food for huge

populations. More than half of the world’s working popula-

tion is employed by some agricultural or agriculturally associ-

ated industry. Almost 40% of the world’s land area is devoted

to agriculture (including permanent pasture). The growing

use of machines, pesticides and man-made fertilizers have

all seriously impacted the environment.

For example, the use of pesticides like DDT in the

1960s were identified as leading to the deaths of certain

species of birds. Most western countries banned use of the

pesticides and the bird populations soon recovered. Today,

use of pesticides is strictly regulated in the United States.

Many more subtle effects of farming occur on the

environment. When grasslands and wetlands or forests are

converted to crops, and when crops are not rotated, eventu-

ally, the land changes to the point that entire species of

plants and animals can become threatened. Urbanization

also imposes onto farmland and cuts the amount of land

available for farming.

Throughout the world, countries and organizations

develop strategies to protect the environment, natural habi-

tats and resources while still supplying the food our popula-

tions require. In 1992, The

United Nations Conference

on Environment and Development

in Rio de Janeiro fo-

cused on how to sustain the world’s natural resources but

balance good policies on environment and community vital-

ity. In the United States, the Department of Agriculture has

published its own policy on sustainable development, which

works toward balancing economics, environment and social

needs concerning agriculture. In 1993, an Executive Order

formed the President’s Council on Sustainable Development

(PCSD) to develop new approaches to achieve economic

and environmental goals for public policy in agriculture.

Guiding principles include sections on agriculture, forestry

and rural community development.

According to the United States

Environmental Pro-

tection Agency

(EPA), Agricultural Environmental Man-

agement (AEM) is one of the most innovative programs in

New York State. The program was begun in June 2000 when

Governor George Pataki introduced legislation to the state’s

Senate and Assembly proposing a partnership to promote

farming’s good stewardship of land and to provide the fund-

ing and support of farmers’ efforts. The bill was passed and

signed into law by the governor on August 24, 2000.

The purpose of the law is to help farmers develop agricul-

tural environmental management plans that control agricul-

tural pollution and comply with federal, state and local regula-

Environmental Encyclopedia 3

Agricultural pollution

tions on use of land, water quality, and other environmental

concerns. New York’s AEM program brings together agencies

from state, local, and federal governments, conservation repre-

sentatives, businesses from the private sector, and farmers. The

program is voluntary and offers education, technical assistance,

and financial incentives to farmers to participate.

An example of a successful AEM project occurred at

a dairy farm in central New York. The farm composted

animals’ solid wastes, which reduced the amount of waste

spread on the fields. This in turn reduced pollution in the

local watershed. The New York State Department of Agri-

culture and Markets oversees the program. It begins when

a farmer expresses interest in AEM. Next, the farmer com-

pletes a series of five tiers of the program.

In Tier I, the farmer completes a short questionnaire

that surveys current farming activities and future plans to

identify potential environmental concerns. Tier II involves

worksheets that document current activities that promote

stewardship of the environment and help prioritize any envi-

ronmental concerns. In Tier III, a conservation plan is devel-

oped that is tailored specifically for the individual farm. The

farmer works together with an AEM coordinator and several

members of the cooperating agency staff.

Under Tier IV of the AEM program, agricultural

agencies and consultants provide the farmer with educa-

tional, technical, and financial assistance to implement best

management practices for preventing pollution to water bod-

ies in the farm’s area. The plans use Natural Resources

Conservation Service standards and guidance from cooperat-

ing professional engineers. Finally, farmers in the AEM

program receive ongoing evaluations to ensure that the plan

they have devised helps protect the environment and also

ensures viability of the farm business.

Funding for the AEM program comes from a variety of

sources, including New York’s Clean Water/Clean Air Bond

Act and the State Environmental Protection Fund. Local Soil

and Water Conservation Districts (SWCDs) also partner in

theeffort,andfarmerscan access fundsthrough these districts.

The EPA says involvement of the SWCDs has likely been a

positive factor in farmers’ acceptance of the program.

Though New York is perceived as mostly urban, agri-

culture is a huge business in the state. The AEM program

serves important environmental functions and helps keep

New York State’s farms economically viable. More than

7,000 farms participate in the program.

[Teresa G. Norris]

ESOURCES

OOKS

Calow, Peter. The Encyclopedia of Ecology and Environmental Management.

Malden, MA: Blackwell Science, Inc., 1998.

ERIODICALS

Ervin, DE, et al. “Agriculture and Environment: A New Strategic Vision.“

Environment 40, no. 6 (July-August, 1998):8.

RGANIZATIONS

New York State Department of Agriculture and Markets, 1 Winners Circle,

Albany, NY USA 12235 (518) 457-3738, Fax: (518)457-3412, Email:

lauren.hoeffner@agmkt.state.ny.us, http://www.agmkt.state.ny.us

Sustainable Development, USA, United States Department of Agriculture,

14th and Independence SW, Washington, DC USA 20250 (202) 720-

5447, Email: rbridge@oce.usda.gov, http://www.usda.gov

Agricultural pollution

The development of modern agricultural practices is one of

the great success stories of applied sciences. Improved plow-

ing techniques, new pesticides and fertilizers, and better

strains of crops are among the factors that have resulted in

significant increases in agricultural productivity.

Yet these improvements have not come without cost to

the

environment

and sometimes to human health. Modern

agricultural practices have contributed to the

pollution

of air,

water, and land.

Air pollution

may be the most memorable, if

not the most significant, of these consequences. During the

1920s and 1930s, huge amounts of fertile

topsoil

were blown

away across vast stretches of the Great Plains, an area that

eventually became known as the

Dust Bowl

. The problem

occurred because farmers either did not know about or chose

not to use techniques for protecting and conserving their

soil

. The soil then blew away during droughts, resulting not

only in the loss of valuable farmland, but also in the pollution

of the surrounding

atmosphere

Soil conservation

techniques developed rapidly in the

1930s, including

contour plowing

, strip cropping, crop ro-

tation, windbreaks, and minimum- or no-tillage farming,

and thereby greatly reduced the possibility of

erosion

such a scale. However, such events, though less dramatic,

have continued to occur, and in recent decades they have

presented new problems. When top soils are blown away

by winds today, they can carry with them the pesticides,

herbicides, and other crop

chemicals

now so widely used.

In the worst cases, these chemicals have contributed to the

collection of air pollutants that endanger the health of plants

and animals, including humans. Ammonia, released from

the decay of fertilizers, is one example of a compound that

may cause minor irritation to the human respiratory system

and more serious damage to the health of other animals and

plants.

A more serious type of agricultural pollution are the

solid waste

problems resulting from farming and livestock

practices. Authorities estimate that slightly over half of all

the solid wastes produced in the United States each year—

a total of about 2 billion tons (2 billion metric tons)—come

Environmental Encyclopedia 3

Agricultural pollution

from a variety of agricultural activities. Some of these wastes

pose little or no threat to the environment. Crop residue

left on cultivated fields and animal manure produced on

rangelands

, for example, eventually decay, returning valu-

able nutrients to the soil.

Some modern methods of livestock management,

however, tend to increase the risks posed by animal wastes.

Farmers are raising a larger variety of animals, as well as

larger numbers of them, in smaller and smaller areas such

feedlots

or huge barns. In such cases, large volumes of

wastes are generated in these areas. Many livestock managers

attempt to sell these waste products or dispose of them in

a way that poses no threat to the environment. Yet in many

cases the wastes are allowed to accumulate in massive dumps

where soluble materials are leached out by rain. Some of

these materials then find their way into

groundwater

surface water, such as lakes and rivers. Some are harmless

to the health of animals, though they may contribute to the

eutrophication of lakes and ponds. Other materials, however,

may have toxic, carcinogenic, or genetic effects on humans

and other animals.

The

leaching

of hazardous materials from

animal

waste

dumps contributes to perhaps the most serious form

of agricultural pollution: the contamination of water sup-

plies. Many of the chemicals used in agriculture today can

be harmful to plants and animals. Pesticides and herbicides

are the most obvious of these; used by farmers to disable or

kill plant and animal pests, they may also cause problems

for beneficial plants and animals as well as humans.

Runoff

from agricultural land is another serious envi-

ronmental problem posed by modern agricultural practices.

Runoff constitutes a

nonpoint source

of pollution. Rainfall

leaches out and washes away pesticides, fertilizers, and other

agricultural chemicals

from a widespread area, not a single

source such as a sewer pipe. Maintaining control over non-

point sources of pollution is an especially difficult challenge.

In addition, agricultural land is more easily leached out than

is non-agricultural land. When lands are plowed, the earth

is broken up into smaller pieces, and the finer the soil parti-

cles, the more easily they are carried away by rain. Studies

have shown that the

nitrogen

and

phosphorus

in chemical

fertilizers are leached out of croplands at a rate about five

times higher than from forest woodlands or idle lands.

The accumulation of nitrogen and phosphorus in wa-

terways from chemical fertilizers has contributed to the accel-

eration of eutrophication of lakes and ponds. Scientists be-

lieve that the addition of human-made chemicals such as

those in chemical fertilizers can increase the rate of eutrophi-

cation by a factor of at least 10. A more deadly effect is the

poisoning

of plants and animals by toxic chemicals leached

off of farmlands. The biological effects of such chemicals

are commonly magnified many times as they move up a

food

chain/web

. The best known example of this phenomenon

involved a host of biological problems—from reduced rates

of reproduction to malformed animals to increased rates of

death—attributed to the use of DDT in the 1950s and

1960s.

Sedimentation

also results from the high rate of ero-

sion on cultivated land, and increased sedimentation of wa-

terways poses its own set of environmental problems. Some

of these are little more than cosmetic annoyances. For exam-

ple, lakes and rivers may become murky and less attractive,

losing potential as

recreation

sites. However, sedimentation

can block navigation channels, and other problems may have

fatal results for organisms. Aquatic plants may become cov-

ered with sediments and die; marine animals may take in

sediments and be killed; and cloudiness from sediments may

reduce the amount of sunlight received by aquatic plants so

extensively that they can no longer survive.

Environmental scientists are especially concerned

about the effects of agricultural pollution on groundwater.

Groundwater is polluted by much the same mechanisms

as is surface water, and evidence for that pollution has

accumulated rapidly in the past decade.

Groundwater

pollution

tends to persist for long periods of time. Water

flows through an

aquifer

much more slowly than it does

through a river, and agricultural chemicals are not flushed

out quickly.

Many solutions are available for the problems posed

by agricultural pollution, but many of them are not easily

implemented. Chemicals that are found to have serious toxic

effects on plants and animals can be banned from use, such

as DDT in the 1970s, but this kind of decision is seldom

easy. Regulators must always assess the relative benefit of

using a chemical, such as increased crop yields, against its

environmental risks. Such as a risk-benefit analysis means

that some chemicals known to have certain deleterious envi-

ronmental effects remain in use because of the harm that

would be done to agriculture if they were banned.

Another way of reducing agricultural pollution is to

implement better farming techniques. In the practices of

minimum- or no-tillage farming, for example, plowing is

reduced or eliminated entirely. Ground is left essentially

intact, reducing the rate at which soil and the chemicals it

contains are eroded away.

[David E. Newton]

ESOURCES

OOKS

Benning, L. E. Agriculture and Water Quality: International Perspectives.

Boulder, CO: L. Rienner, 1990.

———, and L. W. Canter. Environmental Impacts of Agricultural Production

Activities. Chelsea, MI: Lewis, 1986.

Environmental Encyclopedia 3

Agricultural revolution

———, and M. W. Fox. Agricide: The Hidden Crisis That Affects Us All.

New York: Shocken Books, 1986.

Crosson, P. R. Implementation Policies and Strategies for Agricultural Non-

Point Pollution. Washington, DC: Resources for the Future, 1985.

Agricultural Research Service

A branch of the

U.S. Department of Agriculture

charged

with the responsibility of agricultural research on a regional

or national basis. The Agricultural Research Service (ARS)

has a mission to develop new knowledge and technology

needed to solve agricultural problems of broad scope and

high national priority in order to ensure adequate production

of high quality food and agricultural products for the United

States. The national research center of the ARS is located

at Beltsville, Maryland, consisting of laboratories, land, and

other facilities. In addition, there are many other research

centers located throughout the United States, such as the

U.S. Dairy/Forage Research Center at Madison, Wisconsin.

Scientists of the ARS are also located at Land Grant Univer-

sities throughout the country where they conduct cooperative

research with state scientists.

ESOURCES

RGANIZATIONS

Beltsville Agricultural Research Center, Rm. 223, Bldg. 003, BARC-West,

10300 Baltimore Avenue , Beltsville , MD USA 20705 , <http://

www.ars.usda.gov>

Agricultural revolution

The development of agriculture has been a fundamental part

of the march of civilization. It is an ongoing challenge, for

as long as

population growth

continues, mankind will need

to improve agricultural production.

The agricultural revolution is actually a series of four

major advances, closely linked with other key historical peri-

ods. The first, the Neolithic or New Stone Age, marks the

beginning of sedentary (settled) farming. Much of this his-

tory is lost in antiquity, dating back perhaps 10,000 years

or more. Still, humans owe an enormous debt to those early

pioneers who so painstakingly nourished the best of each

year’s crop. Archaeologists have found corn cobs a mere 2

in (5.1 cm) long, so different from today’s giant ears.

The second major advance came as a result of Christo-

pher Columbus’ voyages to the New World. Isolation had

fostered the development of two completely independent

agricultural systems in the New and Old Worlds. A short

list of interchanged crops and animals clearly illustrates the

global magnitude of this event; furthermore, the current

population explosion began its upswing during this period.

From the New World came maize, beans, the “Irish” potato,

squash, peanuts, tomatoes, and

tobacco

. From the Old

World came wheat, rice, coffee, cattle, horses, sheep, and

goats. Maize is now a staple food in Africa. Several Indian

tribes in America adopted new lifestyles, notably the Navajo

as sheepherders, and the Cheyenne as nomads using the

horse to hunt buffalo.

The Industrial Revolution both contributed to and was

nourished by agriculture. The greatest agricultural advances

came in

transportation

, where first canals, then railroads

and steamships made possible the shipment of food from

areas of surplus. This in turn allowed more specialization

and productivity, but most importantly, it reduced the threat

of starvation. The steamship ultimately brought refrigerated

meat to Europe from distant Argentina and

Australia

Without these massive increases in food shipments the ex-

ploding populations and greatly increased demand for labor

by newly emerging industries could not have been sustained.

In turn the Industrial Revolution introduced major

advances in farm technology, such as the cotton gin, mechan-

ical reaper, improved plows, and, in this century, tractors

and trucks. These advances enabled fewer and fewer farmers

to feed larger and larger populations, freeing workers to fill

demands for factory labor and the growing service industries.

Finally, agriculture has fully participated in the scien-

tific advances of the twentieth century. Key developments

include hybrid corn, the high responders in tropical lands,

described as the “Green Revolution,” and current genetic

research. Agriculture has benefited enormously from scien-

tific advances in biology, and the future here is bright for

applied research, especially involving genetics. Great poten-

tial exists for the development of crop strains with greatly

improved dietary characteristics, such as higher protein or

reduced fat.

Growing populations, made possible by these food

surpluses, have forced agricultural expansion onto less and

less desirable lands. Because agriculture radically simplifies

ecosystems and greatly amplifies

soil erosion

, many areas

such as the Mediterranean Basin and tropical forest lands

have suffered severe degradation.

Major developments in civilization are directly linked

to the agricultural revolution. A sedentary lifestyle, essential

to technological development, was both mandated and made

possible by farming. Urbanization flourished, which encour-

aged specialization and division of labor. Large populations

provided the energy for massive projects, such as the Egyp-

tian pyramids and the colossal engineering efforts of the

Romans.

The plow represented the first lever, both lifting and

overturning the soil. The draft animal provided the first in

a long line of nonhuman energy sources. Plant and animal

selectivity are likely the first application of science and tech-

nology toward specific goals. A number of important crops

Environmental Encyclopedia 3

Agricultural Stabilization and Conservation Service

bear little resemblance to the ancestors from which they

were derived. Animals such as the fat-tailed sheep represent

thoughtful cultural control of their lineage.

Climate

dominates agriculture, second only to

irriga-

tion

. Farmers are especially vulnerable to variations, such

as late or early frosts, heavy rains, or

drought

. Rice,

wheat, and maize have become the dominant crops globally

because of their high caloric yield, versatility within their

climate range, and their cultural status as the “staff of

life.” Many would not consider a meal complete without

rice, bread, or tortillas. This cultural influence is so strong

that even starving peoples have rejected unfamiliar food.

China provides a good example of such cultural differences,

with a rice culture in the south and a wheat culture

(noodles) in the north.

These crops all need a wet season for germination

and growth, followed by a dry season to allow spoilage-free

storage. Rice was domesticated in the monsoonal lands of

Southeast Asia, while wheat originated in the Fertile Cres-

cent of the Middle East. Historically, wheat was planted in

the fall, and harvested in late spring, coinciding with the

cycle of wet and dry seasons in the Mediterranean region.

Maize needs the heavy summer rains provided by the Mexi-

can highland climate.

Other crops predominate in areas with less suitable

climates. These include barley in semiarid lands; oats and

potatoes in cool, moist lands; rye in colder climates with

short growing seasons; and dry rice on hillsides and drier

lands where paddy rice is impractical.

Although food production is the main emphasis in

agriculture, more and more industrial applications have

evolved. Cloth fibers have been a mainstay, but paper

products and many

chemicals

now come from cultivated

plants.

The agricultural revolution is also associated with some

of mankind’s darker moments. In the tropical and subtropical

climates of the New World, slave labor was extensive. Close,

unsanitary living conditions have fostered plagues of biblical

proportions. And the desperate dependence on agriculture

is all too vividly evident in the records of historic and contem-

porary

famine

. As a world, people are never more than one

harvest away from global starvation, a fact amplified by the

growing understanding of cosmic catastrophes.

Some argue that the agricultural revolution masks the

growing hazards of an overpopulated, increasingly contami-

nated earth. Since the agricultural revolution has been so

productive it has more than compensated for the population

explosion of the last two centuries. Some appropriately la-

beled “cornucopians” believe there is yet much potential

for increased food production, especially through scientific

agriculture and

genetic engineering

. There is much room

for optimism, and also for a sobering assessment of the

environmental costs of agricultural progress. We must con-

tinually strive for answers to the challenges associated with

the agricultural revolution.

[Nathan H. Meleen]

ESOURCES

OOKS

Anderson, E. “Man as a Maker of New Plants and New Plant Communi-

ties.” In Man’s Role in Changing the Face of the Earth, edited by W. L.

Thomas Jr. Chicago: The University of Chicago Press, 1956.

Doyle, J. Altered Harvest: Agriculture, Genetics, and the Fate of the World’s

Food Supply. New York: Penguin, 1985.

Gliessman, S. R., ed. Agroecology: Researching the Ecological Basis for Sustain-

able Agriculture. New York: Springer-Verlag, 1990.

Jackson, R. H., and L. E. Hudman. Cultural Geography: People, Places, and

Environment. St. Paul, MN: West, 1990.

Narr, K. J. “Early Food-Producing Populations.” In Man’s Role in Changing

the Face of the Earth, edited by W. L. Thomas, Jr. Chicago: The University

of Chicago Press, 1956.

Simpson, L. B. “The Tyrant: Maize.” In The Cultural Landscape, edited

by C. Salter. Belmont, CA: Wadsworth, 1971.

ERIODICALS

Crosson, P. R., and N. J. Rosenberg. “Strategies for Agriculture.” Scientific

American 261 (September 1989): 128–32+.

Agricultural Stabilization and

Conservation Service

For the past half century, agriculture in the United States

has faced the somewhat unusual and enviable problem of

overproduction. Farmers have produced more food than

United States citizens can consume, and, as a result, per

capita farm income has decreased as the volume of crops

has increased. To help solve this problem, the Secretary of

Agriculture established the Agricultural Stabilization and

Conservation Service on June 5, 1961. The purpose of the

service is to administer commodity and land-use programs

designed to control production and to stabilize market prices

and farm income. The service operates through state com-

mittees of three to five members each and committees con-

sisting of three farmers in approximately 3,080 agricultural

counties in the nation.

ESOURCES

RGANIZATIONS

Agricultural Stabilization and Conservation Service, 10500 Buena Vista

Court, Urbandale, IA USA 50322-3782 (515) 254-1540, Fax: (515)

254-1573.

Agriculture and energy conservation

see

Environmental engineering