Environmental Encyclopedia

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Environmental Encyclopedia 3

Cross-Florida Barge Canal

Cronon, William. “:Neither Barren Nor Remote” New York Times (February

28, 2001): A19.

Cross-Florida Barge Canal

The subject of long and acrimonious debate, this attempt

to build a canal across the Florida peninsula began in the

1930s and finally expired in 1990. Although it receives little

attention today, the Cross-Florida Barge Canal stands as a

landmark because it was one of the early cases in which

the

Army Corps of Engineers

, whose primary mission has

traditionally been to re-design and alter natural waterways,

yielded to environmental pressure. The canal’s stated pur-

pose, aside from bringing public works funding to the state,

was to shorten the shipping distances from the East Coast

to the Gulf of Mexico by bypassing the long water route

around the tip of Florida. Rerouting barge traffic would

also bring commerce into Florida, directing trade and trans-

shipment operations through Floridian hands. An additional

supporting argument that persisted into the 1980s was that

the existing sea route brought American commerce danger-

ously close to threatening Cuban naval forces.

Construction on the canal began in 1964, on a route

running from the St. Johns River near Jacksonville west to

the Gulf of Mexico at Yankeetown, Florida. Canal project

plans included three

dams

, five locks, and 110 mi (177 km)

of channel 150 ft (46 m) wide and 12 ft (3. 6 m) deep.

Twenty-five miles (40 km) of this waterway, along with

three locks and three dams, were complete by 1971 when

President Richard Nixon, citing economic inefficiency and

unacceptable environmental risks, stopped the project by

executive order.

From start to finish, the canal’s proponents defended

the project on economic grounds. The Cross-Florida Canal

was proposed as a depression-era job development program.

After completion, commerce and recreational fishing would

boost the state economy. The Army Corps, well-funded and

actively remodelling

nature

in the 1950s and 1960s, took

on the project, vastly overestimating economic benefits and

essentially dismissing environmental liabilities with the argu-

ment that even modest economic gain justified any

habitat

or water loss. After work had begun, further studies con-

cluded that most of the canal’s minimal benefits would go

to non-Floridian agencies and that environmental dangers

were greater than first anticipated. Outcry over environmen-

tal costs eventually led to a reappraisal of economic benefits,

and the state government rallied behind efforts to halt the

canal.

Environmental risks were grave. Although Florida has

wetlands

than any other state except Alaska, many

of the peninsula’s natural wetland and riparian habitats had

already been lost to development,

drainage

, and channeliza-

337

tion. Along the canal route these habitats sheltered a rich

community of migratory and resident birds, crustaceans, fish,

and mammals. Fifteen

endangered species

, including the

red-cockaded woodpecker (Picoides borealis) and the Florida

manatee, stood to loose habitat to channelized rivers and

barge traffic. Specialized spring-dwelling mussels and

shrimp that depend on reliable and pure water supplies in

this porous limestone country were also threatened.

Most serious of all dangers was that to the Floridan

aquifer

, located in northern Florida but delivering water to

cities and wetlands far to the south. Like most of Florida,

the reach between Jacksonville and Yankeetown consists of

extremely porous limestone full of

sinkholes

, springs, and

underground channels. The local

water table

is high, often

within a few feet of the ground surface, and currents within

the aquifer can carry water hundreds of meters or more in

a single day. Because the canal route was to cut through 28

mi (45 km) of the Floridan aquifer’s

recharge zone

, the

area in which water enters the aquifer, any pollutants escap-

ing from barges would disperse through the aquifer with

alarming speed. Even a small fuel leak could contaminate

millions of gallons of drinking-quality water. In addition,

a canal would expose the aquifer to extensive urban and

agricultural pollution

from the surrounding region.

Water loss presented another serious worry. A channel

sliced through the aquifer would allow water to drain out

into the sea, instead of remaining underground. Evaporation

losses from impounded lakes were expected to reach or ex-

ceed 40 million gallons of fresh water every day. With water

losses at such a rate, water tables would fall, and salt water

intrusions into the fresh water aquifer would be highly proba-

ble. In 1985, 95% of all Floridians depended on

ground-

water

for home and industrial use. The state could ill afford

the losses associated with the canal.

Florida water management districts joined environ-

mentalists in opposing the canal. By the mid-1980s the

state government, eager to reclaim idle land easements for

development, sale, and extension of the Ocala

National

Forest

, put its weight against the Corps and a few local

development agencies that had been resisting deauthoriza-

tion for almost 20 years. In 1990 the United States Congress

voted to divide and sell the land, effectively eliminating all

possibility of completing the canal.

[Mary Ann Cunningham Ph.D.]

ESOURCES

ERIODICALS

Hogner, R. H. “Environmentalists Lock Up Canal Development.” Business

and Society Review (Fall 1990): 74-77.

Environmental Encyclopedia 3

Paul J. Cruzen

THER

Deauthorization Hearings: The Cross-Florida Barge Canal. United States

House of Representatives Committee on Public Works 1978. Washington,

DC: U. S. Government Printing Office, 1978.

Hearing on the Cross-Florida Barge Canal. United States House of Represen-

tatives Committee on Public Works June 10, 1985. Washington, DC: U.

S. Government Printing Office, 1985.

CRP

see

Conservation Reserve Program (CRP)

Paul J. Cruzen (1933 – )

Dutch Meteorologist

Paul Crutzen is one of the world’s leading researchers in

mapping the chemical mechanisms that affect the

ozone

layer. He has pioneered research on the formation and deple-

tion of the ozone layer and threats placed upon it by industrial

society. Crutzen has discovered, for example, that

nitrogen

oxides

accelerate the rate of ozone depletion. He has also

found that

chemicals

released by bacteria in the

soil

affect

the thickness of the ozone layer. For these discoveries he

has received the 1995 Nobel Prize in Chemistry, along with

Mario Molina and Sherwood Rowland for their separate

discoveries related to the ozone and how

chlorofluorocar-

bons

(CFCs) deplete the ozone layer. According to Royal

Swedish Academy of Science, “by explaining the chemical

mechanisms that affect the thickness of the ozone layer, the

three researchers have contributed to our salvation from a

global environmental problem that could have catastrophic

consequences.”

Paul Josef Crutzen was born December 3, 1933, to

Josef C. Crutzen and Anna Gurek in Amsterdam. Despite

growing up in a poor family in Nazi-occupied Holland dur-

ing 1940–1945, he was nominated to attend high school at

a time when not all children were accepted into high school.

He liked to play soccer in the warm months and ice skate

50–60 mi (80–97 km) a day in the winter. Because he was

unable to afford an education at a university, he attended a

two-year college in Amsterdam. After graduating with a

civil engineering degree in 1954, he designed bridges and

homes.

Crutzen met his wife, Tertu Soininen, while on vaca-

tion in Switzerland in 1954. They later moved to Sweden

where he got a job as a computer programmer for the Insti-

tute of

Meteorology

and the University of Stockholm. He

started to focus on atmospheric chemistry rather than mathe-

matics because he had lost interest in math and did not want

to spend long hours in a lab, especially after the birth of his

two daughters, Illona and Sylvia. Despite his busy schedule,

338

Crutzen obtained his doctoral degree in Meteorology at

Stockholm University at the age of 35.

Crutzen’s main research focused on the ozone, a bluish,

irritating gas with a strong odor. The ozone is a molecule

made up of three oxygen atoms (O

) and is formed naturally

in the

atmosphere

by a

photochemical reaction

. The

ozone begins approximately 10 mi (16 km) above Earth’s

surface, reaching between 20–30 miles (32–48 km) in height,

and acts as a protective layer that absorbs high-energy

ultra-

violet radiation

given off by the sun.

In 1970 Crutzen found that soil

microbes

were excre-

ting

nitrous oxide

gas, which rises to the

stratosphere

and is converted by sunlight to nitric oxide and

nitrogen

dioxide. He determined that these two gases were part of

what caused the depletion of the ozone. This discovery revo-

lutionized the study of the ozone and encouraged a surge

of research on global biogeochemical cycles.

In 1977, while he was the director of the National

Center for Atmospheric Research (NCAR) in Boulder, Col-

orado, Crutzen studied the effects of burning trees and brush

in the fields of Brazil. Every year farmers cleared the forests

by burning everything in sight. The theory at the time was

that this burning caused more

carbon

compounds or trace

gases and

carbon monoxide

to enter the atmosphere. These

gases were believed to cause the

greenhouse effect

,ora

warming of the atmosphere. Crutzen collected and examined

this

smoke

in Brazil and discovered that the complete oppo-

site was occurring. He stated in Discover magazine: “Before

the industry got started the tropical burning was actually

decreasing the amount of

carbon dioxide

in the atmo-

sphere.” The study of smoke in Brazil led Crutzen to further

examine what effects larger amounts of different kinds of

smoke might have on the

environment

, such as smoke from

a nuclear war.

The journal Ambio commissioned Crutzen and John

Birks, his colleague from the University of Colorado, to

investigate what effects nuclear war might have on the planet.

Crutzen and Birks studied a simulated worldwide nuclear

war. They theorized that the black carbon soot from the

raging fires would absorb as much as 99% of the sunlight.

This lack of sunlight, coined “nuclear inter,” would be devas-

tating to all forms of life. For this theory Crutzen was named

“Scientist of the Year” by Discover magazine in 1984 and

awarded the prestigious Tyler Award four years later.

As a result of the discoveries by Crutzen and other

environmental scientists, a very crucial international treaty

was established in 1987. The Montreal Protocol was negoti-

ated under the auspices of the United Nations and signed

by 70 countries to slowly phase out the production of chloro-

fluorocarbons and other ozone-damaging chemicals by the

year 2000. However, the United States had ended the pro-

duction of CFCs five years earlier, in 1995. According to the

Environmental Encyclopedia 3

Cryptosporidium

New York Times, “the

National Oceanic and Atmospheric

Administration

reported in 1994, while ozone over the

South Pole is still decreasing, the depletion appears to be

leveling off.” Even though the ban has been established,

existing CFCs will continue to reach the ozone, so the

depletion will continue for some years. The full recovery of

the ozone is not expected for at least 100 years.

From 1977–80, Crutzen was director of the Air Qual-

ity Division, National Center for Atmospheric Research

(NCAR), located in Boulder, Colorado. While at NCAR,

he located he taught classes at Colorado State University in

the department of Atmospheric Sciences. Since 1980 he has

been a member of the Max Planck Society for the Advance-

ment of Science, and he is the director of the Atmospheric

Chemistry division at Max Planck Institute for Chemistry.

In addition to Crutzen’s position at the institute, he is a

part-time professor at Scripps Institution of Oceanography

at the University of California. In 1995 he was the recipient

of the United Nations Environmental Ozone Award for

outstanding contribution to the protection of the ozone layer.

Crutzen has co-authored and edited several books, as well

as having published several hundred articles in specialized

publications.

[Sheila M. Dow]

ESOURCES

OOKS

Cruzen, Paul. Atmosphere, Climate, and Change. Scientific American Li-

brary, 1995.

———. Atmosphere Change: An Earth System Perspective. W.H. Free-

man, 1993.

———. Environmental Consequences of Nuclear War 1985. Schwarzer Him-

mel, 1986.

Cryptosporidium

Cryptosporidium is a microscopic protozoan parasite that is

a significant cause of diarrheal disease (cryptosporidiosis) in

humans and animals, including ruminants, swine, cats, and

dogs. The word cryptosporidium means hidden spore, refer-

ring to the ease with which it can escape detection in environ-

mental samples. Most cryptosporidiosis appears to be caused

by the

species

Cryptosporidium parvum. The dormant and

resistant forms of Cryptosporidium, referred to as oocysts, are

excreted in the feces of infected humans and animals and

can survive under a wide range of environmental conditions.

Cryptosporidiosis had long been recognized as a veterinary

problem, especially in young farm animals, but was only

recognized as a cause of human disease in 1976, when it

was diagnosed in animal handlers.

339

The most common symptom of cryptosporidiosis is

watery diarrhea. Other symptoms may include abdominal

cramps, nausea, low-grade fever, dehydration, and weight

loss. Symptoms usually develop four to six days after infec-

tion, but may occur from two to 10 days after infection. In

individuals with healthy, normal immune systems, the dis-

ease usually only lasts for several days, and rarely more than

two weeks. Some infected persons may not even become ill,

while others become ill, seem to recover, but become ill

again. Infected persons may shed oocysts in their feces for

months, even when they are not exhibiting disease

symptoms.

Cryptosporidiosis can cause complications in persons

with diabetes, alcoholism, or pregnancy. Diarrhea and dehy-

dration can severely affect the very young, the elderly, and

the frail. Cryptosporidiosis can be prolonged and life-threat-

ening in immuno-compromised individuals (those who have

weak immune systems), such as transplant patients, people

infected with the Human Immunodeficiency

Virus

(HIV)

(which causes Acquired Immuno-Deficiency Syndrome

[AIDS]),

cancer

patients on chemotherapy, and persons

who are taking medications that suppress the immune sys-

tem. By 1983, the number of infections in humans was

increasing as the

AIDS

epidemic began; also diagnostic meth-

ods were developed to identify the parasite in stool samples,

which aided in the identification and documentation of the

disease.

In industrialized nations, about 0.4% of the population

passes oocysts in the feces at any one time, while about 2–

2.5% of patients admitted to hospitals are passing oocysts.

About 30–35% of the United States population have anti-

bodies in their blood to Cryptosporidium. In developing na-

tions, the prevalence is higher, where up to 60–70% of people

have circulating antibodies in their blood to Cryptosporidium.

In AIDS patients, the numbers of individuals with chronic

cryptosporidiosis is about 10% in industrialized nations and

up to 40% in some developing nations.

Cryptosporidiosis cannot be diagnosed by symptoms

alone, but must be confirmed with a specific diagnostic stool

test for the parasite. There is no drug available to cure

cryptosporidiosis. Symptoms are treated with anti-diarrheal

medicines and fluids to prevent dehydration. People with

strong immune systems will recover on their own and may

develop limited immunity to recurring infections.

A person can become infected with Cryptosporidium

by ingesting anything that has been in contact with feces

from an infected person or animal. Hands can become con-

taminated with Cryptosporidium through person-to-person

contact, such as changing of a child’s diaper, caring for

someone with diarrhea, or touching a part of the body con-

taminated with feces. Cryptosporidiosis is easily spread

through social groups, such as families, day care centers, and

Environmental Encyclopedia 3

Cryptosporidium

nursing homes. Persons who work with animals or touch

soils or objects contaminated with feces can contract crypt-

osporidiosis.

Infection with Cryptosporidium can also occur by

drinking water that is contaminated with oocysts. The first

report of spread of cryptosporidiosis through a municipal

drinking water system was in 1987 in Carrollton, Georgia,

where 13,000 people, out of a total population of 65,000,

became ill. In 1993, a municipal drinking water system in

Milwaukee, Wisconsin, became contaminated with Crypt-

osporidium, and 400,000 people became ill. Four thousand

people were hospitalized, at a cost of $54 million, and 100

people died, including some persons with AIDS. Both water

systems had met all state and drinking water standards.

There have also been more than a dozen outbreaks reported

in the United Kingdom. These outbreaks demonstrated the

risks of waterborne cryptosporidiosis, for unfortunately

Cryptosporidium oocysts are resistant to many environmental

stresses and chemical disinfectants such as

chlorine

that are

used in municipal drinking water systems and swimming

pools (swallowing a small amount of water while swimming

in a chlorinated pool can cause cryptosporidiosis). The mech-

anism that protects oocysts from

chlorination

has not yet

been positively identified—the oocyst membrane may be

protective, or an oocyst may pump

toxins

from its cell before

the toxins can cause harm.

Oocysts are present in most surface bodies of water

in the United States, many of which are sources of public

drinking water. They become more prevalent during periods

runoff

(generally from March-June during spring rains

in North America) or when

wastewater

treatment plants

become overloaded or break down. Properly drilled and

maintained

groundwater wells

, with intact well casings,

proper

seals

, and above-ground caps, are not likely to con-

tain Cryptosporidium because of natural

filtration

through

soil

and

aquifer

materials.

The detection of Cryptosporidium oocysts is unreliable,

for recovery and enumeration of oocysts from water samples

is difficult. Concentration techniques for oocysts in water

samples are poor, and detection methods often measure algae

and other debris in addition to oocysts. The volume of water

required to concentrate oocysts for detection can range from

26–264 gal (100–1,000 l). Determination of whether oocysts

are infective and viable or a member of the species that

causes disease is not easy to accomplish. The development

of more accurate, rapid and improved assays for oocysts

is required, for present tests are time-consuming, highly

subjective, and dependent on the skills of the analyst.

In addition, the number of oocysts (the effective dose)

required to cause cryptosporidiosis has not yet been well-

defined and requires more investigation. Studies to date have

suggested that the 50% infectious dose may be around 132

340

oocysts, and in some cases, as few as 30 oocysts (infections

have also occurred with the ingestion of a single oocyst).

Human susceptibility to Cryptosporidium likely varies be-

tween individuals and between various Cryptosporidium

strains.

Therefore protection of drinking water supplies from

contamination by Cryptosporidium requires multiple ap-

proaches. Filtration of drinking water supplies is the only

reliable conventional treatment method. Water in a treat-

ment plant is mixed with coagulants that aid in the settling

of particles in water; removal can be enhanced by using sand

filtration.

Ozone

disinfection can kill Cryptosporidium but

ozone does not leave a residual in the distribution system

as chlorine does, which provides protection of treated water

to the point of use but does not neessarily kill Cryptosporidium

anyway.

Watershed

protection to prevent contamination from

entering water sources is also important in protection of

drinking water supplies. Regulation of septic systems and

best management practices

can be used to control runoff

of human and animal wastes.

An individual can also take steps to ensure that drink-

ing water is safe. Boiling water (bringing water to a rolling

boil for at least one minute) is the best way to kill Cryptospori-

dium. After boiling, the water should be stored in the refrig-

erator in a clean bottle or pitcher with lid; care should be

taken to avoid touching the inside of the bottle or lid to

prevent re-contamination. Point-of-use

filters

, either

attached to a faucet, or the pour-through type, can also be

used to remove Cryptosporidium from water. Only filters

with an absolute, rather than a nominal, pore size of one

micron or smaller should be used to remove oocysts. Reverse

osmosis filters are also effective. Lists of filters and reverse

osmosis filters that will remove Cryptosporidium oocysts can

be obtained from NSF International, an independent non-

profit testing agency.

The use of bottled water is not necessarily safer than

tap water, as water from a surface water source has the same

risks of containing oocysts as tap water from that source,

unless it has been treated with appropriate treatment tech-

nologies, such as distillation, pasteurization, reverse osmosis,

or filtration with an absolute one micron rating, before bot-

tling. Bottled water from deep groundwater wells has a low

likelihood of being contaminated with oocysts, so the labels

on water bottles should be examined before use to determine

water source and treatment methods.

Food can also be a source of Cryptosporidium. In 1996,

in the Northeastern United States, unpasteurized apple cider

and juice was associated with Cryptosporidium infections. In

1997, in Spokane, Washington, members of a group at-

tending a dinner banquet become ill with cryptosporidiosis.

The parasite may be present in uncooked or unwashed fruits

Environmental Encyclopedia 3

Cubatao, Brazil

and vegetables that are grown in areas where manure was

used or animals were grazed or in beverages or ice prepared

with contaminated water. Pasteurization of dairy products

will kill oocysts. Bottled and canned drinks, such as soda

and beer, are usually heated and/or filtered sufficiently to

kill or remove Cryptosporidium oocysts. Care should be taken

to wash hands thoroughly with soap and water before eating,

preparing or serving food. Fruits and vegetables that will be

eaten raw should be washed or peeled before being eaten.

When traveling to areas with poor

sanitation

, extra care

should be taken in the selection of food and drink.

[Judith L. Sims]

ESOURCES

OOKS

Fayer, Ron, ed.Cryptosporidium and Cryptosporidiosis. Boca Raton, FL: CRC

Press, 1997.

Frey, Michelle, Carrie Hancock, and Gary S. Logsdon. Cryptosporidium:

Answers to Questions Commonly Asked by Drinking Water Professionals. Den-

ver, CO: American Water Works Association, 1998.

Small, Mitchell J., ed. Protocol for Cryptosporidium Risk Communication.

Denver, CO: American Water Works Association, 2002.

Rose, Joan B., and Huw V. Smith. Giardia and Cryptosporidium Handbook:

A Practical Guide. Boca Raton, FL: CRC Press, 2000.

ERIODICALS

Conrad, Laura. “The Tedious Hunt for Cryptosporidium.” Today’s Chemist

at Work 7 (1998): 24–26.

Guerrant, Richard L. “Cryptosporidiosis: An Emerging, Highly Infectious

Threat.” Emerging Infectious Diseases January/March 1997 [June 2002]

<http://www.cdc.gov/ncidod/EID/vol3no1/guerrant.htm>.

THER

Cryptosporidium: A Waterborne Pathogen. Water Quality Information Cen-

ter, National Agricultural Library, Agricultural Research Center, U.S. De-

partment of Agriculture. May 1996 [May 2002]. <http://www.nal.usda.gov/

wqic/cornell.html>.

“Cryptosporidium parvum.” Bad Bug Book. Foodborne Pathogenic Microor-

ganisms and Natural Toxins Handbook, Center for Food Safety & Applied

Nutrition, U.S. Food and Drug Administration. February 13, 2002 [June

2002]. <http://vm.cfsan.fda.gov/~mow/chap24.html>.

Fact Sheet: Cryptosporidium. Division of Parasitic Diseases, National Center

for Infectious Diseases, Centers for Disease Control and Prevention. May

2001 [June 2002]. <http://www.cdc.gov/ncidod/dpd/parasites/cryptospori-

diosis/factsht_cryptosporidiosis.htm>.

Fact Sheet: Preventing Cryptosporidiosis—A Guide to Water Filters and Bottled

Water. Division of Parasitic Diseases, National Center for Infectious Dis-

eases, Centers for Disease Control and Prevention. August 15, 1999 [June

2002]. <http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/

factsht_crypto_prevent_water.ht>.

CSOs

see

Combined Sewer Overflows

341

Cubatao, Brazil

Once called the “valley of death” and the “most polluted

place on earth,” Cubatao, Brazil, is a symbol both of severe

environmental degradation

and how people can work

together to clean up their

environment

. A determined effort

to reduce

pollution

and restore the badly contaminated air

and water in the past decade has had promising results.

While not ideal by any means, Cubatao is no longer among

the worst places in the world to live.

Cubatao is located in the state of Sa

o Paulo, near the

Atlantic coastal city of Santos, just at the base of the high

plateau on which Sa

o Paulo—Brazil’s largest city—sprawls.

Thirty years ago, Cubatao was an agreeable, well-situated

town. Overlooking Santos Bay with forest-covered mountain

slopes rising on three sides around it, Cubatao was well

removed from the frantic hustle and bustle of Sa

o Paulo on

the hills above. Several pleasant little rivers ran through the

valley and down to the sea. When the rivers were dammed to

generate electricity in the early 1970s, however, the situation

changed.

Cheap energy and the good location between Sa

Paulo and the port of Santos attracted industry to Cubatao.

An oil refinery, a steel mill, a

fertilizer

plant, and several

chemical factories crowded into the valley, while workers

and job-seekers scrambled to build huts on the hillsides and

the swampy lowlands between the factories. With almost

pollution control

enforcement, industrial smokestacks

belched clouds of dust and toxic effluents into the air while

raw sewage and chemical waste poisoned the river. By 1981,

the city had 80,000 inhabitants and accounted for 3% of

Brazil’s industrial output. It was called the most polluted

place in the world. More than 1,000 tons of toxic gases were

released into the air every day. The steaming rivers seethed

with multi-hued chemical slicks, foamy suds, and debris.

No birds flew in the air above, and the hills were covered

with dying trees and the scars of

erosion

where rains washed

dirt down into the valley.

Sulfur dioxide

, which damages lungs, eats away

building materials, and kills vegetation, was six times higher

than World Health Organization guidelines. After a few

hours exposure to sunlight and water vapor, sulfur oxides

turn into sulfuric

acid

, a powerful and dangerous corrosive

agent. Winter air inversions would trap the noxious gases

in the valley for days on end. One quarter of all emergency

medical calls were related to respiratory ailments. Miscar-

riages, stillbirths, and deformities rose dramatically. The

town was practically uninhabitable.

The situation changed dramatically in the mid-1980s,

however. Restoration of democracy allowed citizens to orga-

nize to bring about change. Governor Franco Montoro was

elected on promises to do something about pollution, and

Environmental Encyclopedia 3

Cultural eutrophication

his administration came through on campaign promises.

Between 1983 and 1987, the government worked with in-

dustry to enforce pollution laws and to share the costs of

clean-up. Backed by a

World Bank

loan of $100 million,

the state and private industry invested more than $200 mil-

lion for pollution control. By 1988, 250 out of 320 pollution

sources were reduced or eliminated. Ammonia releases were

lowered by 97%,

particulate

emissions were reduced 92%,

and sulfur dioxide releases were cut 84%. Ozone-producing

hydrocarbons

and volatile organic compounds dropped

nearly 80%. The air was breathable again. Vegetation began

to return to the hillsides around the valley, and birds were

seen once more.

Water quality

also improved. Dumping of trash and

industrial wastes was cut from some 64 metric tons per day

to less than 6 tons. Some 780,000 tons of

sediment

were

dredged out of the river bottoms to remove toxic contami-

nants and to improve water flow. Fish returned to the rivers

after a 20-year absence. Reforestation projects are replanting

native trees on hillsides where mudslides threatened the

town. The government of Brazil now points to Cubatao

with pride as an illustration of its concern for environmental

protection. This is a heartening example of what can be

done to protect the environment, given knowledge, commit-

ment, and cooperation.

[William P. Cunningham Ph.D.]

ESOURCES

ERIODICALS

“Cubatao: Brazil’s Ecological Success.” Financial Times (10 June 1988).

“Cubatao: New Life in the Valley of Death.” World Resources 1990-91.

Washington, DC: World Resources Institute, 1991.

Cultivation

see

Agricultural pollution

Cultural eutrophication

One of the most important types of

water pollution

, cul-

tural eutrophication describes human-generated fertilization

of water bodies. Cultural denotes human involvement, and

eutrophication means truly nourished, from the Greek word

eutrophic. Key factors in cultural eutrophication are

nitrates

and

phosphates

, and the main sources are treated sewage

and

runoff

from farms and urban areas. The concept of

cultural eutrophication is based on anthropocentric values,

where clear water with minimal visible organisms is much

preferred over water rich in green algae and other

microor-

ganisms

342

Nitrates and phosphates are the most common lim-

iting factors for organism growth, especially in aquatic eco-

systems. Most fertilizers are a combination of

nitrogen

phosphorus

, and potassium. Nitrates are key components

of the amino acids,

peptides

, and proteins needed by all

living organisms. Phosphates are crucial in energy transfer

reactions within cells. Natural sources of nitrates (and am-

monia) are more readily available than phosphates, so the

latter is often cited as the crucial limiting factor in plant

growth. Nitrates are supplied in limited quantities by de-

caying plant material and nitrogen-fixing bacteria, but phos-

phates must come from animal bones, organic matter, or

from the breakdown of phosphate-bearing rocks. Conse-

quently, the introduction and widespread use of phosphate

detergents

, combined with excess

fertilizer

in runoff, has

produced a near ecological disaster in some waters.

In ecosystems, there is a continuous cycling of matter,

with green algae and plants making food from

chemicals

dissolved in water via

photosynthesis

; this provides the

food base needed by herbivores and carnivores. Dead plant

material and animals are then decomposed by

aerobic

(oxy-

gen using) and

anaerobic decomposers

into the simple

elements they came from. Natural water bodies are usually

well-suited for handling this matter cycling; however, human

impacts often inject large amounts of additional nutrients

into the system, changing them from

oligotrophic

(poorly

nourished) to eutrophic water bodies. Once present within

a relatively closed body of water, such as a lake or

estuary

these extra nutrients may cycle numerous times before leav-

ing the system.

Green algae and trashy fish may thrive in eutrophic

water, but most people are offended by what they perceive

as “scum.” Nutrient-poor water is usually clear and possesses

a rich supply of oxygen, but as the

nutrient

load increases,

oxygen levels drop and turbidity rises. For example, when

sewage is dumped into a body of water, the sewage fertilizes

the algae, and as they multiply and die the aerobic decom-

posers multiply in turn. The increased demand for oxygen

by the decomposers outstrips the system’s ability to provide

it. As a result,

dissolved oxygen

levels may fall or sag even

below 2.0

parts per million

, the threshold below which

even trashy fish cannot a survive (trout need at least 8.0

ppm to survive). Even though the green algae are producing

oxygen as a byproduct of photosynthesis, even more oxygen

is consumed by decomposers breaking down the dead algae

and other organisms.

As water flows downstream the waste is slowly broken

down, so there is less for the decomposers to feed on. Biolog-

ical oxygen demand slowly falls, while the dissolved oxygen

levels rise until the river is finally back to normal levels.

Most likely, the nutrients recycled by decomposers are either

diluted, turned into

biomass

by trees and consumer organ-

Environmental Encyclopedia 3

Cultural eutrophication

Oxygen sag downstream of a source of organic pollution. (McGraw-Hill Inc. Reproduced by permission.)

isms, or tied up in bottom sediments. Thus a river can

naturally cleanse itself of

organic waste

if given sufficient

time. Problems arise, however, when discharges are too large

and frequent for the river to handle; under extreme condi-

tions it becomes “dead” and is suited only for low-order,

often anaerobic, organisms. Municipalities using river water

locate their intakes upstream and their

sewage treatment

plants and storm drains downstream. If communities were

required to do the reverse, the quality of river water would

dramatically improve.

The major sources of nitrates and phosphates in

aquatic systems are treated sewage

effluent

; excess fertilizer

from farms and urban landscapes; and animal wastes from

feedlots

, pastures, and city streets. In some areas with pris-

tine waters, such as

Lake Tahoe

, tertiary sewage treatment

has been added; chemicals are used to reduce nitrate and

phosphate levels prior to

discharge

Runoff from nonpoint sources is a far more difficult

problem because they are harder to control and remediate

than runoff from point sources. Point sources can be diverted

into treatment plants, but the only feasible way to reduce

nonpoint sources is by input reduction or by on-site control.

343

Less fertilizer more frequently applied, especially on urban

lawns, for example, would help reduce runoff. Feedlots are

a major concern; runoff needs to be collected and treated in

the same manner as human sewage; this may also apply to

street runoff. Green cattle ponds are a sure sign of the

abundant nutrients supplied by these mobile meat factories.

Phosphate detergents are superior cleaning agents than

soap, but the resultant

wastewater

is loaded with this key

limiting factor. Phosphate levels in detergents have since

been reduced, but its impact is so powerful that abatement

may require tertiary treatment.

The battle between Oklahoma and Arkansas over Illi-

nois River

pollution

provides a useful case study of the

debate over cultural eutrophication. This river has its head-

waters in Arkansas and has become a prime tourist attraction

in Oklahoma. Enthusiasts come from all over to canoe the

river; summer use is especially heavy. However, economic

development within the basin has resulted in a steady decline

in river quality.

Arkansas started a legal war with Oklahoma when it

sought and obtained

Environmental Protection Agency

Environmental Encyclopedia 3

Cuyahoga River

(EPA) approval to dump half of the treated sewage from a

new plant in Fayetteville into a tributary of the Illinois.

Arkansas argued that its state-of-the-art treatment plant

would produce an effluent having little impact on

water

quality

by the time it reached the border. Oklahoma coun-

tered that it could not risk the potential economic loss if

the river became polluted.

This controversy has had a salutary impact on research

into the causes of cultural eutrophication within this basin.

Scientists from Oklahoma State University and the Univer-

sity of Arkansas are collaborating on a long-term study of

river quality and pollution sources. It is highly likely that

nonpoint sources within both states will be identified as the

key culprits, especially from livestock operations.

There is one major success story in the battle to over-

come the effects of cultural eutrophication. The Thames

River in England was devoid of aquatic life for centuries.

Now a massive cleanup effort is restoring the river to vitality.

Many fish have returned, most notably the pollution-sensi-

tive

salmon

, which had not been seen in London for 300

years. However, much work remains, especially in former

Warsaw Pact countries and those in the

Third World

[Nathan H. Meleen]

ESOURCES

OOKS

Pettyjohn, W. A. Water Quality in a Stressed Environment. Minneapolis:

Burgess, 1972.

ERIODICALS

Canby, T. “Water: Our Most Precious Resource.” National Geographic 158

(August 1980): 144-179.

Harleman, D. R. F. “Cutting the Waste in Wastewater Cleanups.” Technol-

ogy Review 93 (April 1990): 60-69.

Herber, L. “Cool, Refreshing--and Filthy.” In The Human Habitat: Contem-

porary Readings, edited by David L. Wheeler. New York: Van Nostrand

Reinhold, 1971.

Maurits la Riviere, J. W. “Threats to the World’s Water.” Scientific American

261 (September 1989): 80-84+.

Cuyahoga River

This 103-mi (166-km) long tributary of

Lake Erie

is a classic

industrial river, with, however, one monumental distinction:

it caught fire–twice. The first fire, in 1959, burned for eight

days; fireboats merely spread the blaze. Typical of the times,

a November 1959 article in Fortune seemed to glorify the

industrial

pollution

here, with words and a portfolio of

drawings reminiscent of Charles Dickens. Inspired by feel-

ings of space and excitement, the artist stated: “It is a great

expanse, with a smoky cast over everything, smudged with

orange dust from the ore–an overall brown color.” Cleveland-

344

ers consoled themselves that the foul water at least symbol-

ized prosperous times.

The second fire occurred on June 22, 1969, as several

miles of river along the lowland industrial section called “the

Flats” ignited, fed by bunker oil, trash, and tree limbs trapped

by a bridge 6 mi (9.7 km) upstream. This fire, along with the

Santa Barbara oil well blowout, provided graphic television

images which were projected around the world. Jack A.

Seamonds’s June 18, 1984 article in U.S. News & World

Report credited the fire with lighting “the fuse that put the

bang in the nationwide campaign to clean up the environ-

ment.” Pamela Brodie described it in the September-Octo-

ber 1983 issue of Sierra as “The most infamous episode of

water pollution

in the U.S...It inspired a song...and the

Clean Water Act.”

Although the fire badly hurt Cleveland’s image, steps

were already underway to correct the problem. The city

government had declared the river a fire hazard and won

voter approval in the autumn of 1968 for major funding to

correct sewage problems. After the fire, Cleveland’s three

image-conscious steel companies voluntarily quit dumping

cyanide-laced water and two installed cooling towers. As a

result of just these actions alone, the river once again began

to freeze in the winter. The city of Akron banned phosphate

detergents

, and eventually won the lawsuits brought against

it by soap companies. These and other efforts, plus comple-

tion in 1983 of the major

sewage treatment

project,

brought about far more encouraging reports.

The Cuyahoga was formerly dumping 155 tons of

waste per day, and was even devoid of

sludge

worms. But by

1978, Business Week could report substantial improvement:

phosphates

were cut in half;

chemicals

were down 20–

40%; and

oil spills

went from 300 per year to 25 in 1977.

For the first time, local residents saw ducks on the river. By

1984,

point source

pollution had been largely eliminated.

The waterfront was rediscovered, with restaurants and trendy

stores where once fires had burned

The water is still light brown, churned up by deep-

water shipping, and Lake Erie is still polluted. Nonetheless,

the Cuyahoga seems to have been largely redeemed, and

thus helped revitalize the city of Cleveland. The river became

one of 14 American Heritage rivers in 1998. See also Great

Lakes; Oil Pollution Act (1990); Water quality

[Nathan H. Meleen]

ESOURCES

ERIODICALS

Brodie, P. “The Clean Water Act; New Threats From Toxic Waste Demand

Stronger Law.” Sierra 68 (September-October 1983): 39-44.

Lawren, B. “Once Aflame and Filthy, A River Shows Signs of Life.”

National Wildlife 28 (February-March 1990): 24.

Environmental Encyclopedia 3

Cyclone collector

Seamonds, J. A. “In Cleveland, Clean Waters Give New Breath of Life.”

U. S. News & World Report 96 (18 June 1984): 68-9.

Wood, W. “Ecological Drums Along the Cuyahoga.” American Education

9 (January 1973): 15-21.

Cyclodienes

see

Chlorinated hydrocarbons

Cyclone

see

Tornado and cyclone

Cyclone collector

A device that removes solids from an

effluent

stream (solid/

liquid or solid/gas) using gravitational settling. The input

stream enters a vertical tapered cylinder tangentially and

spiral fins or grooves cause the stream to swirl. The centrifu-

gal force created by this swirling action causes particles to

settle out of the input stream. These solids are concentrated

at the walls and move to the bottom of the tapered cone.

The solid-free fluid or gas is removed along the center line

of the collector via a vortex finder. A

cyclone

collector is a

compact device capable of processing large volumes of efflu-

ent; however, pressure energy is expended in its operation.

It removes particles from the effluent stream less effectively

than bag

filters

electrostatic precipitation

. See also Bag-

house

345

A cyclone collector. (McGraw-Hill Inc. Reproduced by

permission.)

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