man began with speech, and civilization with agriculture, industry
began with fire. Man did not invent it, probably nature produced the
marvel for him...He put the wonder to a thousand uses. First, perhaps...
to conquer his fearsome enemy, the dark; then...for warmth,...then
he applied it to metals, tempering them, and combining them into stronger
and suppler than those in which they had come to his hand..."
with fire, "industry" or, in these early days, humans learned
to use energy to manipulate materials, transforming them to suit our purposes.
These rearrangements, while bringing great progress, has also left us
with large prices to pay because of our disregard or ignorance of evolving
the material use on a scale of time and space that learned its lessons
from natural material cycles.
material cycles described in the previous sections are a part of our ecosystem.
Over billions of years, materials, energy and life have all evolved with
mutual interactions to become part of a natural ecology. Most materials
that form part of the biosphere occur in cycles, especially those that
play central roles in biological systems.
of materials by humans has changed over time in quantity and quality,
and especially over the last century. The early use of materials for food,
shelter and energy required small amounts of materials for each person
and were conserved to large extent because it was hard to get, shape and
work with materials. Often, materials remained as part of a product such
as a tool or a plough for decades and were reused or recycled.
of material use in products have changed significantly with the technological
age - particularly in the 20th century. Plastics are perhaps the most
radical material invention, in the way that material permeated society.
In 1900, 75% of products used renewable materials (that is, agricultural
and forest materials, such as wood and natural fibers). By 1980, 70% of
materials used were from non-renewable sources such as ores, minerals,
and petroleum. In 1955, 8% of materials in products were petroleum-based
(plastics). By 1980, 32% of materials in products were petroleum-based.
stone were the earliest "materials" to be shaped and used by
humans. In the course of time, natural materials such as clay and mud
were used for cooking and building. With the advance of technology, discoveries
of ways to extract metals from ores, methods to shape and transform materials,
and eventually with the knowledge afforded by synthetic, organic, and
nuclear chemistry, we have made numerous combinations of materials that
have never existed in nature. The age of "synthetic" materials
started with forming alloys of metals. Bronze (an alloy of tin and copper),
brass (an alloy of zinc and copper), and gold alloys (14 carat gold is
14 parts of gold and 10 parts of copper; 24 carat gold is pure gold metal)
have all been used since ancient civilization.
transformations of materials gave humans the ability to shape materials
into forms they wanted. As pure gold is too soft and pliable, the addition
of copper was an early invention to make gold stronger. Metallic elements
were alloyed to increase strength to make strong and lasting tools, structures
and weapons. Iron, copper, sulfur and phosphorus were probably the materials
that received the greatest attention for these uses as "industry"
emerged. Of course, stones of various kinds, including marble (CaCO3),
granite, gypsum (MgSO4), sand (SiO2) were all used
since early times for building. There were also fuel materials such as
wood, coal, and oil, - hydrocarbons - that were used first to build fires,
then for controlled extraction of energy.
technological capabilities, the human ingenuity and art (techne in Greek
means art or "cunning" as in Charles Dickens' Artful Dodger)
combined with scientific understanding led to unprecedented arrangements
and transformations of materials. In pressing to get the functionality
of various desirable properties and technological progress in designing
and producing new materials, we did not know or think of these materials
as part of our natural environmental system. In extracting them from the
natural system, and combining them into new forms, we began concentrating
materials, producing materials that did not exist in nature, and extracting
or "purifying" into elemental form large quantities of elements
that existed in nature only in chemical combinations with others.
processes, there was no awareness of how much "useless" material
- wastes - was produced as we extracted the "useful" material,
or of the role that "indestructible" synthetic or even natural
materials may play when released into the environment after their use
in unprecedented quantities over relatively short periods of time. The
greatest ignorance we exhibit as an industrialized "civilization"
is perhaps a lack of respect or even a total ignorance - of the role of
time and of cycles in providing system balance. In pressing on with our
economy, we lost sight of our ecology!
Ayres, one of the originators of the idea of industrial ecology summarizes
the crux of our material use in the beginning paragraph of his book Industrial
Ecology, co-authored with Leslie Ayres.
substance extracted from the earth's crust, or harvested from a forest,
a fishery or from agriculture, is a potential waste, it soon becomes
an actual waste in almost all cases, with a delay of a few weeks to
a few years at most. The only exception worth mentioning are long-lived
construction materials. In other words, materials consumed by the industrial
economic system do not physically disappear. They are merely transformed
to less useful forms. In some cases (as with fuels) they are considerably
transformed by combination with atmospheric oxygen. In other cases (such
as solvents and packaging materials) they are discarded in more or less
the same form as they are used. It follows from this simple relationship
between inputs and outputs - a consequence of the law of conservation
of mass - that economic growth tends to be accompanied by equivalent
growth in waste generation and pollution." (Ayres 1)
this realization has not fully hit most parts of our society even today,
the 1960's environmental consciousness articulated three features/problems
of the industrial rearrangement of material: resource depletion, increasing
waste materials, and the presence of toxic materials in the environment.
The first idea - resource depletion which came from industry - was the
realization that the earth does not have an infinite bank of materials.
The second of increasing waste came from people noticing the ugliness
of waste - as garbage on highways, junked cars, the "blooms"
of algae in lakes from over-nitrificiation from detergents and pesticides,
or mounds of mining overburden. The presence of toxic materials in the
environment was a slower realization, spurred most notably by Rachel Carsons'
Silent Spring which has a chapter titled "And the Birds Sing No More"
to signify the impact of the pesticide DDT which weakened the eggshells
this century, industrial countries did not consider pollution or resource
shortage a serious problem. When resources in the home countries were
hard to access, trade or conquests were used to procure material. Historians
Will and Ariel Durant make the point that the Industrial Revolution came
to England first because of the long history of British command of the
seas, because science in England was mainly "directed by men of practical
bent", and because England had a constitutional government sensitive
to business interests.
to resource depletion in this century was a foray into ideas of conservation
and resource management, finding out how the economies of recycling would
compare with the economies of resource extraction from nature. Thus early
in this century, the aluminum industry began its quest for recycling.
Aluminum recycling is one of the most advanced processes of recycling
because of decades of learning. Conservation ideas also developed through
the desire to conserve the natural beauty of forests and other landscapes.
1970's, economic and political pressures such as the oil cartel and depletion
of coal led to ideas of energy conservation in the United States. Energy-intensive,
material-producing industries such as aluminum, and paper started serious
looks into recycling. Energy conservation measures in the U.S. also led
to down-sizing of cars, which had hitherto gone on with the philosophy
of "bigger the better" - station wagons for family uses and
recreational vehicles for vacations were a common sight during the economic
upsurge of the 1950's and early 1960's. Automobile recycling became big
and achieved 90% material recovery in the 1980's.
1994, the National Environmental Technology Act was passed to encourage
the government to work with industry to promote technologies that will
have positive environmental impact. Particularly, the government was interested
in and more efficient and non-polluting technologies so that we can maintain
our current standard of living in light of population growth. In the Senate,
those supporting the measure contended that "coming up with new,
nonpolluting technologies will ultimately help efficiency and the economy."1
these conservation measures were, of course, totally anthropocentric,
with an objective of preserving our conveniences, and meeting our wants
and desires. It was not the ethos of conservation
practiced by older civilizations with a respect for value and an eye to
the future - to the "seventh generation" as described in the
unit on Ethical Systems. (link)
resource depletion, we began defining materials as renewable and nonrenewable
resources. Materials like coal that can only be replaced over long periods
of time compared to the time periods of human activities involving their
use, are called nonrenewable resources. Materials such as wood which can
in reasonable periods of time are called renewable resources. Note that
these are renewable only if we replant trees at a rate that keeps up with
use. Thus the Redwoods or old-growths
forest trees should not be looked on as "renewable" resources
because of the time it would take to replace.
waste and its disposal was the second mounting problem. Europe with its
older industrial base and limited land area felt the waste problem sooner
and more acutely than the United States. The concentration of people -
and hence of quantities of waste is higher in the urban areas. In his
book, (link to anobib) The Search for the Ultimate Sink, historian Joel
Tarr writes that urban pollution is the "product of the interaction
among technology, scientific knowledge, human culture and values and the
environment", reduced or exacerbated at times with environmental
policy and control technology. Sinking of waste and recycling of usable
items have been a part of all cultures. But an economy that valued overproduction
and marketed convenience items as necessary to the quality of life and
the accompanying perception we have of an inexhaustible resource supply
has led to a throwaway society, especially in the U.S.
analyzing environmental problems, we focus on industrial generation of
waste, without a full realization that industry generates waste to meet
consumer demands. In 1976, an average consumer spent 15% of his/her income
on "durable goods" - automobiles and parts, furniture and other
appliances, 18.5% on food, and 22% on "nondurable goods" such
as clothing and shoes, gasoline, and alcoholic beverages! (U.S. Bureau
of Economic Analysis-link?)
in analyzing environmental problems, we focus on industrial generation
of waste, without a full realization that industry generates waste
to meet consumer demands. In 1976, an average consumer spent 15%
of his/her income on "durable goods" - automobiles and
parts, furniture and other appliances, 18.5% on food, and 22% on
"nondurable goods" such as clothing and shoes, gasoline,
and alcoholic beverages! (U.S. Bureau of Economic Analysis) Calculate
the percentages of income spent by a consumer on durable goods,
food, and non durable goods for 1996 and the current year.
found the U.S. in ridiculous scenarios such as: a boat of garbage from
New York City floating in the Hudson River and mountains of Uranium mill
tailings blowing radioactive material around some of the western United
States. In addition to garbage and sewage, industrial wastes in air, water,
and land have also posed formidable problems. The philosophy of waste
management has been evolving slowly, spurred by regulation, but making
slow progress in the U.S. because of various types of social perceptions.
in the environment is a much subtler problem. Basically, the problem arises
when we produce new compounds or isolate elements in configurations not
found in nature with properties such as a resistance to degradation. Many
of these materials do not decompose on exposure to the usual agents that
nature uses to decompose air, light, water, or bacteria. Persistent
substances, such as plastics and chlorofluorocarbons, produce cumulative,
long-term and long-range effects on plant, animal and human health.
cases the effects were not predictable because of our lack of knowledge
and the absence of consideration of systemic, long-term impacts. Joe Thornton
writes in (anobib link) Pandora's Poison, a book on the impacts of chlorine
compounds, "the chemistry of the chlorine atom gives chlorine gas
and organochlorines useful properties, but these same qualities (high
reactivity and chemical stability) create enormous environmental problems...Organochlorines
that are stable in their intended use, however, are also persistent in
the environment." [Thornton]. Organochlorines, other organic compounds
and metals give rise to health hazards such as cancer and endocrine disruptions
discussed in the unit on Heath and Risk.
Bureau of Mines maintains an account of the world production and flows
of metals and other primary materials such as coal and other fossil fuels.
Table 4 shows the amount of some metal ores extracted in 1988.
of Ore KMT
of Metal KMT
& Mill Waste
4. World Production of some Metals and mine waste in 1000 metric
tonnes (KMT) (adapted from Ayres 1996)
shows that each pound of aluminum extracted produces 1-7 pounds of waste
at the mine, and almost all of the uranium ore is waste! The main intent
of the table is to show the amounts of waste at the very first stage
mining and milling in the production of a metal. Note that in all
cases, we produce much more waste than metal. This is only the beginning.
Each stage of production of a consumer good such as an automobile or a
toaster, requires many more stages of manufacturing, each with its own
wastes discarded to air, land, and water.
of Copper and Aluminum
_ and _ are flowcharts showing the stages in the use of two metals
copper and aluminum. The flow of copper is shown only from the mine to
the point of input into an industrial process. The figure for Aluminum
is drawn to represent the whole sequence of use, including recycling.
These flow charts are the beginning stages of doing a life cycle analysis
which we describe in the next section on Industrial Ecology. In the unit
on Energy Systems, we have shown similar diagrams for the production of
energy from different sources.
IU4. Scheme of copper metal flow from mine to entry into manufacturing
million metric tons (18,000 million lbs.) of copper is mined annually.
The two main countries producing copper are Chile and the U.S., each producing
about 2 million MT annually. Canada, the former USSR, Zaire, Zambia and
Poland are the other countries. Copper is usually mined via open pits.
large amount of processing, each process with its other inputs and wastes,
copper metal is delivered to the various industries that use it. Because
copper is used in alloys such as brass and wires, it is difficult to extract
and reuse the metal economically. Separation is one of the major obstacles
in the attempt to recycle copper.
the oldest known metal to be extracted and used by humans. There are signs
of copper use as early as 6000 B.C. toward the end of the Neolithic Age,
considered by historians as the beginning of the Age of Metals. Alloying
copper with tin or zinc to form bronze and brass seems to have happened
by 3000 B.C. and other metallurgical heat-treatment processes like casting
seems to have started by 1500 B.C. (Durant, Vol. I, p. 103).
IU5. Aluminum flowchart
plays a very crucial role in modern society. It is the basis of aircraft
and large mirrors used in telescopes! It is a versatile metal. The extraction
and processing of aluminum from its ore - bauxite, Al2O3
is environmentally destructive. Aluminum is not abundant in the
earth's crust (14.3 atomic % or 8% by mass compared to 27.7% for Si (Silicon)
and 5% for Fe (Iron), but it is in combination with oxygen. This strong
combination requires a lot of energy to break!
producers of aluminum are Australia, Guinea, Jamaica and Brazil with much
smaller amounts from Greece, France and Hungary. To separate aluminum
(pure Al2O3) from the bauxite ore which also contains
Fe2O3, SiO2, TiO2 and other
minerals, a significant amount of electricity, water and chemicals such
as limestone (CaCO3) and Caustic Soda (NaOH) are needed. Separation
of the metal Al from Al2O3 is done by means of an
electrolytic process that consumes large amounts of electricity. Because
of this, the companies producing aluminum had, in the early days, also
developed hydroelectric power plants close to the mines. Thus the Tacurai
Dam in Brazil sends one-third of its output electricity to aluminum smelters!
the extraction of Aluminum from the Alumina (Al2O3)
ore requires an enormous amount of electrical energy, the aluminum industry
initiated processes to recycle the used aluminum and was one of the first
industries to do so. For many other materials, the sequence is not closed,
that is, the used product is not processed to get the original material
List the materials in a familiar consumer product such as toaster,
clothes, soap, cleaners. Find the source of the material and where
it ends up finally.
in the Case of a Consumer "Material" : Packaging
In the previous
two cases, and in the material cycles earlier in the unit, we looked at
the flows and cycles of materials that occur in nature. A large and diverse
group of materials central to the consumer economy of today is all the
material that could be categorized as packaging. The amounts and flows
of packaging materials is an important aspect to consider because of their
large effect on the environment.
including cartons, cans, and bottles used for consumer items are individually
small but contribute to resource use and waste because of the sheer number
of units we use. Packaging also has an often overlooked aspect; their
centralized production and large distribution systems mean that we transport
a large amount of consumer items over long distances, each with its own
packaging. Thus transportation involves large expenditures of energy.
includes containers (made of glass, metals, or plastics), one-use containers
(paper, plastic bags, cartons, and toothpaste tubes) and wrapping materials
(paper, plastic, Aluminum foil). Recycling of packaging materials is very
limited in the U.S. In 1993, we used about 310 kg (or 700 lbs.) per person
of paper and paperboard for packaging, leading to a total of 80 million
metric tons. Europe uses more plastics than paper because of the relative
scarcity of land to grow wood.
As two examples
of packaging materials, we now briefly describe the schemes of flow of
paper and plastic. Paper and paperboard products are made mostly from
wood pulp, and some paper from plant fibers such as cotton, linen and
outlines the scheme of material flow of paper.
tons of paper are made per day in the U.S. to satisfy the 700 lbs per
person per day demand. In 1996, 45% of post consumer waste paper was recycled,
and the industry has set a 50% paper recovery goal. ("Industrial
Environmental Performance Metrics," NAE Press, 1999.)
the industry in the U.S. is attempting to obtain wood grown on plantations
or intensively managed forests rather than use wood from natural forests.
Still, some of the tropical forests in South America and South East Asia
are being harvested at alarming rates to provide wood for paper.
process uses high amounts of electricity and water 2000 Kwh and
8000 gallons of water per ton of pulp produced. Large amounts of energy
is also used when "pulp mats" are dried over hot rolls to become
paper. The processing of paper, and especially the bleaching, consumes
large amounts of chemicals. In particular, several million tons of chlorine
are used which combines with the organic material in the process waste
to produce over 1,000 types of organochlorine by-products. About 50 tons
of organochlorines are released into water and air by an average size
paper mill. Organochlorine byproducts are also concentrated in the sludge,
80% of which are buried in landfill. Environmental damage to plants, aquatic
life and health risks to workers are well documented effects of paper
mill effluents. The byproducts include dioxins which are both hazardous
and bioaccumulative. Health and water pollution concerns have led the
paper industry to look into chlorine free bleaching processes such as
using ozone. A new family of bleaching compounds that decompose into water
and oxygen has been developed by Professor Terry Collins of Carnegie Mellon
of the different media - air, water, and land - are discussed in the unit
on the Atmospheric System, in the section on water cycle in this unit,
and in the following section on solid and hazardous waste. Rethinking
the use of materials using principles of ecology and "closing the
circle" (a term used first by Barry Commoner) is the topic of the
next section on Industrial Ecology.
1. Choose an appliance you use daily.
List as accurately as possible, the materials in the appliance
(excluding energy source). Consider how long you would keep it
and what happens to it after you no longer use it. Draw a flow
chart of the system of production, use, and the after-use of the
appliance. Consider barriers and incentives to recycling the materials.
Add to the flow chart arrows to indicate energy inputs and water
Try to describe as closely as possible the "final" fate
of each material. What are the differences from the way they existed
originally and their final form?