Till M. Bachmann

Case studies on emissions from single facilities

Publisher Summary This chapter reveals that the Impact Pathway Approach is extended by ingestion exposures according to the methodology and is applied to case studies. Two different kinds of case studies are presented in the chapter. The chapter focuses on the first kind, addresses the derivation of marginal external costs because of the operation of single power plants. The other assesses the overall quantifiable external costs because of pan-European emissions into air for the situation in 1990. The marginal emission-related case studies investigate the influence of the location of point sources on the marginal external costs because of the exposure toward the trace elements under study. The resulting, quantifiable marginal external costs will be put into perspective by comparing them to those caused by the emission of the classical air pollutants such as SO 2 , NO x , NH 3 , NMVOC and primary particles reported. To define the scope of the respective case studies, one needs to specify: the technology to be assessed, the location of emissions (e.g., at the power plant, supporting activities), and the fuel (type, source and composition).

5 - Modelling the environmental fate in the terrestrial environment

Publisher Summary This chapter presents the environmental fate modeling approach for the terrestrial environment. The chapter discusses the modeling of concentrations in terrestrial compartments distinguished by land uses and/or covers (such as agricultural soils) and modeling of contaminants in (terrestrial) plants. Pure environmental fate models describe the relationship between emissions and concentrations trying to quantitatively answer the question of “how much of a substance ends up where.” Thus, model development and set-up may require different subdivisions of the zones in terms of compartments distinguished and parameterization of these compartments if one has to develop a pure environmental fate model or an exposure model. The chapter discusses the various compartments distinguished in the terrestrial environment. When assessing indirect human exposures, plants need to be considered because they form the basis of most of the food chains or webs because of their role as primary producers. Reasons for distinguishing between several plant compartments either as different plant parts or as different plant species include: different plant parts are exposed because of different processes (especially foliar vs. root uptake, but also attachment of (particle-bound or gaseous) substances to plant aboveground surfaces), consumption occurs only of selected plant components (e.g., root, leafy, stem and corn produces) and different plant parts or species are affected to different degrees by processes such as harvesting, litter fall and growth.

9 - Evaluation of results

Publisher Summary This chapter presents an overview on the different concepts how to evaluate exposure and impact assessment models. Furthermore, the approach is outlined and applied by which the reliability of the results with respect to impact assessment and their valuation at the European scale shall be assessed. The chapter discusses the different approaches for the evaluation of results. One way of subdividing the validation process is into the components (a) operational or whole model validation, (b) theoretical or conceptual validity, and (c) data validation of which only the operational and data components can be validated whereas theory cannot. A thorough in-depth evaluation of the presented external cost assessment would constitute a major task in its own right. Therefore, a more semi-quantitative approach to model evaluation is followed in the chapter. The purpose of the Impact Pathway Approach is to provide external cost estimates that are specific to a human activity, be it a single or a collective/societal activity. This way it supports the decision-making process with respect to conducting cost-benefit analyses of different policy options. The chapter focuses the external costs resulting from human health impacts that are because of indirect exposure to provide decision-support at the European Union level and/or its member countries including acceding and (potential) accession countries.

Exposure and impact assessment

Publisher Summary This chapter focuses on the assessment of a substance’s concentration in agricultural produce and freshwater fish, the food intake, and the impact assessment. The chapter considers different types of produce (e.g., potatoes, cereals, spinach), pork, poultry, eggs, beef and dairy products, and freshwater fish in the analysis. It has been argued that drinking water is excluded basically because of data availability constraints. As regards fish, only freshwater fish is included albeit most of the fish eaten in Europe stems from sea catches. The disregard of exposure via marine fish is because of the fact that sea fish is caught at very different places that would bring about the necessity to (a) assess the environmental fate of especially long-lived chemicals at the global scale (i.e., modelling the entire oceanic system on Earth) because of marine currents and migrating animals, and (b) to include rather detailed trade patterns. The chapter presents that ingestion rates are formulated as consumption of an average individual of the population—that is, without distinguishing among, for example, different age groups. Although consumption habits and amounts as well as body weight will be different between adults and children, there is no effect model available taking into account that effects occurring because of oral exposure to the substances investigated are prevalent for one population subgroup or the other.

4 - Multimedia environmental fate assessment framework: outline, atmospheric modelling and spatial differentiation

Publisher Summary This chapter describes the methodology that allows the assessment of exposures through soil and water which in turn lead to monetisible impacts. The methodology is implemented in a new module complementing the software tool EcoSense. This module is called “integrated WATer and SOil environmental fate, exposure and impact assessment model of Noxious substances” (WATSON). The methodological approach is built on an existing air quality-related external cost assessment scheme that has been described in the chapter. Its regional air quality model has been presented. WATSON is linked to this air quality model whose deposition fields serve as input to the terrestrial and aquatic environment. Reasons under which conditions such a coupling is justified and how the coupling is performed have been discussed in the chapter. Based on the deposition field or on direct emission specifications to soil and/or water, the approach assesses the environmental fate in different soil and water compartments.

6 - Modelling the environmental fate in the aquatic environment

Publisher Summary This chapter describes the environmental fate modeling approach for the aquatic environment. As for the terrestrial environment, the description is generally distinguished into modeling of concentrations in water bodies and aquatic organisms. When talking about “water,” in principle one may distinguish it according to its composition: fresh and salty water; phases: liquid, solid and gaseous water, and macroscopic occurrence—that is, water bodies at the surface or the subsurface (e.g., groundwater). The chapter reveals that surface freshwater bodies are included in the assessment. Segmented model distinguishes two water compartments: one containing moving waters and other representing stagnant waters just above the sediment and in shallower regions of the river. When performing spatially-resolved environmental fate assessments different zones are distinguished whose freshwater and sediment compartments may be allowed to vary in terms of dimensions and properties.

12 - Concluding remarks

Publisher Summary This chapter demonstrates that to perform the external cost assessment in as complete a way as possible, the work has to be developed and applied an extension of the impact pathway approach (IPA) termed WATSON (integrated WATer and SOil environmental fate, exposure and impact assessment model of Noxious substances). WATSON facilitates the coverage of exposures toward hazardous substances released into air, (fresh) water and soil through ingestion of various food items in a spatially-resolved pan-European setting. The approach comprises several special features that shall be recapitulated in the following includes the overall method relies on a coupled set of environmental fate models for air on the one hand and for soil and (fresh) water on the other. While the assessment for air has been adopted from the existing software tool EcoSense (European Commission, 2003d), the contaminants’ environmental fate in the terrestrial and aquatic environment is described with the help of a spatially-resolved climatological box model similar to Mackay level III/IV models (Mackay, 1991). Both fate models assume long-term average conditions for the description of the environment. In line with current political concern, the focus is laid on persistent substances such as heavy metals. In particular, the trace elements arsenic, cadmium, chromium and lead are investigated. The methodological development has, therefore, focused on this substance group that had been poorly addressed previously in the realm of multimedia modeling.

11 – Whole economy case study

Publisher Summary This chapter considers the case study of pan-European emissions into air for the situation in the year 1990. The chapter investigates the overall external costs resulting from activities of whole societies or economies. To be able to follow the impact pathway approach for a whole economy, information on all releases of the contaminants to be assessed into the environment is needed. The impact assessment because of inhalation is based on the corresponding (effective) Intake Fractions. The effective Intake Fraction because of inhalation translates into DALYs according to the respective cancer and non-cancer slope factors. The assessment of the ingestion-related human exposures is performed based on the environmental settings of the “food removal” scenario. As for the single facilities, the four trace elements analyzed show marked differences in terms of both the absolute value of the effective intake fraction because of ingestion exposures and the temporal development of this measure. The damages because of arsenic and chromium contribute about a factor of two and about three orders of magnitude less than those for cadmium, respectively. When comparing the total quantifiable external costs because of ingestion discounted at 3 % to the most dominant damage costs because of inhalation—that is, those of the classical air pollutants, discounted at the same rate—the contribution is marginal. Including substances other than the classical air pollutants in the assessment, thus, leads to an increase in the total quantifiable external costs at most in the order of less than one percent when discounting at 3 % according to the presently available information.