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The principal terminology used in MFA studies is as fol-
lows (Graedel and Allenby, 2003, pp. 284–289; Brunner and
Rechberger, 2004, pp. 34–40):Substance: Any (chemical) element or compound
composed of uniform units
Material: Substances and combinations thereof, both
uniform and nonuniform
Goods: Entities of matter with a positive or negative
economic value, comprised of one or more sub-
stances
Process: The operation of transforming or transporting
materials
Flux: The rate at which an entity enters or leaves a
process
Budget: An accounting of the receipts, disbursements,
and reserves of a substance or material
Cycle: A system of connected processes that transfer
and conserve substances or materialsThe central principle upon which MFA is based is that of
mass balance, which states that the mass of all inputs into
a process equals the sum of the mass of all outputs and
any mass accumulation (or depletion) that occurs within.
This renders the results of MFA useful for studies of
resource availability, recycling potential, environmental
loss, energy analysis, and policy studies. MFA may be per-
formed on a local scale and from a technical engineering
perspective (as in Type A in Table 1), or, on a broader scale,associated with a geopolitical or socioeconomic dimension
(as in Type B in Table 1; Bringezu and Moriguchi, 2002).
In each case there is the potential for achieving a better
understanding of the materials aspects of the process or
entity under study, as well as identifying opportunities for
achieving improvements.Life-Cycle AssessmentLCA is a tool broadly used by industrial ecologists to
identify and quantify the environmental impacts associated
with a product, progress, service, or system across its “cradle-
to-grave” life stages. Unlike the more targeted examination
of a product or process in order to understand and quantify its
direct environmental impacts, the use of a life-cycle perspec-
tive enables one to examine the direct and indirect environ-
mental effects of an object through the stages of extraction of
raw materials; various manufacturing, fabrication, and trans-
portation steps; use; and disposal or recycling.
LCA began in the United States in 1969, in an effort
to compare several types of beverage containers and deter-
mine which of them produced the lesser effect on natural
resources and the environment (Levy, 1994; U.S. EPA,
2004). Since the 1990s, the Society for Environmental
Toxicology and Chemistry in North America and Europe
and the U.S. Environmental Protection Agency (EPA) have
worked to promote consensus on a framework for conduct-
ing life-cycle inventory analysis and impact assessment. In
1993, the International Organization for Standardization19601970198019902000R. Carson, SILENT SPRING, 1962B. Ward et al., ONLY ONE EARTH, 1972United Nations Conference on Human
Environment, 1972D.H. Meadows et al., LIMITS TO GROWTH, 1972WCED, OUR COMMON FUTURE, 1987Foundation of UNEP, 1972United Nations Conference on Environment
and Development (1st Earth Summit), 19922nd Earth Summit, 2002Founding of ISIE, 2000T.E. Graedel, Professor of industrial ecology, 1997Yale & MIT. JOURNAL OF INDUSTRIAL ECOLOGY, 1997T.E. Graedel and B.R. Allenby, INDUSTRIAL ECOLOGY, 1995
NTNU, Industrial ecology degree, 1996R. Frosch and N. Gallopoulos,
STRATEGIES FOR MANUFACTURING, 1989R.U. Ayres, Industrial metabolism, 1980sNational Academy of Science’s Colloquium on
Industrial Ecology, USA, 1991Industrial ecology’s appearance in the literature, 1970s
Beginning of industrial symbiosis in Kalundborg, 1970sFIGURE 2 Industrial ecology and sustainable development: time line of events.C009_002_r03.indd 505C009_002_r03.indd 505 11/18/2005 10:30:26 AM11/18/2005 10:30:26 AM