The tool for the reduction and assessment of chemical and other environmental impacts (TRACI) is a set of life-cycle impact assessment (LCIA) characterization methods that has been developed by a series of U.S. Environmental Protection Agency research projects. TRACI facilitates the characterization of stressors that may have potential effects, including ozone depletion, global warming, acidification, eutrophication, tropospheric ozone (smog) formation, eco-toxicity, human particulate effects, human carcinogenic effects, human non-carcinogenic effects, fossil fuel depletion, and land-use effects. This article describes the methodologies developed to address acidification, eutrophication, and smog. Each of these methods offers the ability to take account of differences in expected strength of impact as a function of pollution release location within North America. Specifically, the methods employ regionalized fate and transport modeling. The resulting factors differ regionally by up to more than an order of magnitude.
Increasing residential insulation can decrease energy consumption and provide public health benefits, given changes in emissions from fuel combustion, but also has cost implications and ancillary risks and benefits. Risk assessment or life cycle assessment can be used to calculate the net impacts and determine whether more stringent energy codes or other conservation policies would be warranted, but few analyses have combined the critical elements of both methodologies. In this article, we present the first portion of a combined analysis, with the goal of estimating the net public health impacts of increasing residential insulation for new housing from current practice to the latest International Energy Conservation Code (IECC 2000). We model state-by-state residential energy savings and evaluate particulate matter less than 2.5 μm in diameter (PM2.5, NOx, and SO2 emission reductions. We use past dispersion modeling results to estimate reductions in exposure, and we apply concentration-response functions for premature mortality and selected morbidity outcomes using current epidemiological knowledge of effects of PM2.5 (primary and secondary). We find that an insulation policy shift would save 3 × 1014 British thermal units or BTU (3 × 1017 J) over a 10-year period, resulting in reduced emissions of 1,000 tons of PM2.5, 30,000 tons of NOx, and 40,000 tons of SO2. These emission reductions yield an estimated 60 fewer fatalities during this period, with the geographic distribution of health benefits differing from the distribution of energy savings because of differences in energy sources, population patterns, and meteorology. We discuss the methodology to be used to integrate life cycle calculations, which can ultimately yield estimates that can be compared with costs to determine the influence of external costs on benefit-cost calculations.
Refinements of methods for life cycle impact assessment (LCIA) are directed at removing unjustified simplifications and quantifying and reducing uncertainties in results. The amount of uncertainty reduction that is actually achieved through LCIA method refinement depends on the structure of the life cycle inventory model. We investigate the general structure of inventory models using an economic input/output (I/O) life cycle assessment model of the U.S. economy. In particular, we study the results of applying a streamlining algorithm to the I/O LCA model. The streamlining algorithm retains only those “branches” of the process tree that are jointly required to account for a specified fraction of the total impacts upstream of each point in the tree. We examine the implications of these “tree pruning” results for site-informed LCIA. Percentiles are presented for U.S. commodities and several important pollutants, for the share of total upstream emissions contributed by the set of processes in each supply tier, that is, each set of processes that directly supply inputs to another set of processes. Capturing at least 90% of the total direct plus upstream emissions for criteria air pollutants and toxic releases for at least 75% of the commodities in the U.S. economy requires full modeling of direct emissions plus the first five supply tiers. The requirements for capturing a high percentage (e.g., > 80%) of total emissions vary widely across products or commodities. To capture more than 60% of total emissions for more than half of all commodities requires models with more than 4,000 process instances. To well characterize the total impacts of products, life cycle impact assessment methods must characterize foreground process impacts in a site-informed way and mean impacts of far-removed processes in an unbiased way.
Main objectives of the project are:
1. To introduce the environmental data in the design processes
2. To facilitate data exchange and independence from any computer system
Those objectives are both “key points” and “bottle necks” for a wider diffusion of LCA and eco- design tools.
They are achieved adapting the standards developed for the communication of product, process and property data in design and manufacturing to the requirements for LCA. Three types of standards for computerised information representation and communication have been adopted:
• ISO 10303 provides entity-relationship models for product, property and process data;
• ISO 15926 provides classification structures for the description of industrial data
• Web ontology provide web-based classification structures for the description of information.
These standards are used for the representation of examples of LCA data in accordance with ISO 14048 and their communication between different systems.
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Chapter 4.12 on "Dispersal of invasive species and GMO": Increased dispersal of invasive species, alien to the local ecosystems, may happen as a result of intentional introductions or as an unintentional side-effect of creating new corridors or dispersal vectors. The largest impact is due to transport vectors, such as ballast water of freighters, soil sticking to trucks and souvenirs brought home by tourists or business travellers. Intentional introductions is mainly relevant for agri-, silvi- and aquaculture. The dispersal of genes introduced via genetically modified organisms is generally a more limited problem due to stricter legal approval procedures, but its potential impact can be modelled in the same way as dispersal of natural species.
Chapter 4.12 on "Use of Natural Resources": In this section a general proposal on the way to handle different types of natural resources, including water, minerals, energy carriers, soil and biotic resources is presented first. Secondly, more detailed considerations are provided for subcategories water use, minerals, soil erosion and soil salination and dessication are presented.
This paper presents a model for prioritisation within the integrated product policy. The description of the model contains more precise technical details, but is relatively brief and therefore requires prior understanding of the fundamental concepts of environmental life cycle assessment and input-output analysis, such as presented in the Nielsen & Weidema (2001).
The model description serves as a specification of the model development during phase 2 of the project “Prioritisation within the integrated product policy” funded by the Danish Environmental Protection Agency.
According to the predefined Terms of Reference, this definition study aims in priority:
1) To identify user needs for Life Cycle Impact Assessment (LCIA)
2) To provide a clear picture of an overall LCIA framework and of the impact categories to address as high priority, including different impacts than the one typically applied in "OECD country LCAs", like e.g. erosion or biodiversity
3) To identify the main research needs and to produce a 2 years detailed plan, with a prospect of 4 years for the LCIA programme.
4) To identify worldwide experts from relevant fields, as potential candidates to ask for peer review, workgroups or task forces.
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The use of stochastic models and the presentation of ranges and confidence intervals enhances the decision support capabilities of an LCA study. However, an uncertainty analysis should not merely quantify the uncertainty output, but provide a mechanism to direct effort back into the LCA models to manage those uncertainties. This paper demonstrates the valuable assistance an uncertainty assessment can provide to an LCA study, including the selection of meaningful criteria against which to evaluate systems, directing further data collection and modeling effort, and systematically generating scenarios for comparison. The uncertainty assessment takes place according to a 3-layered framework, which is based on the recognition that different sources of uncertainty require different methods for their analysis and reduction.
