Summary
The tool for the reduction and assessment of chemical and
other environmental impacts (TRACI) is described along with its
history, the research and methodologies it incorporates, and the
insights it provides within individual impact categories.
TRACI, a stand-alone computer program developed by the U.S.
Environmental Protection Agency, facilitates the charac-terization of
environmental stressors that have potential ef-fects, including ozone
depletion, global warming, acidification, eutrophication, tropospheric
ozone (smog) formation, eco-toxicity, human health criteria睦elated
effects, human health cancer effects, human health noncancer effects,
fossil fuel depletion, and land-use effects. TRACI was originally
designed for use with life-cycle assessment (LCA), but it is expected
to find wider application in the future. To develop TRACI, impact
categories were selected, avail-able methodologies were reviewed, and
categories were pri-oritized for further research. Impact categories
were charac-terized at the midpoint level for reasons including a
higher level of societal consensus concerning the certainties of
modeling at this point in the cause-effect chain. Research in the
impact categories of acidification, smog formation, eutrophication,
land use, human cancer, human noncancer, and human criteria pollutants
was conducted to construct methodologies for rep-resenting potential
effects in the United States. Probabilistic analyses allowed the
determination of an appropriate level of sophistication and spatial
resolution necessary for impact modeling for each category, yet the
tool was designed to accommodate current variation in practice (e.g.,
site-specific information is often not available). The methodologies
under-lying TRACI reflect state-of-the-art developments and
best-available practice for life-cycle impact assessment (LCIA)
in the United States and are the focus of this article. TRACI痴 use and
the impact of regionalization are illustrated with the example of
concrete production in the northeastern United States.
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