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(distance to the emission source and elevation in the terrain). The geographic data
are crucial for this type of assessment. In this case the Tarragona region in Spain
was selected as the area of study and information about elevation, population density,
and the meteorological situation was provided.
The physical impacts and, as far as possible, the resulting damage costs are
calculated by means of pollutant short-range and long-range transport and conversion
models and the exposure–response functions for several receptors (human and eco-
systems). These can be selected by the user for each individual grid cell (for the
case under study, the grid cell corresponds to the Tarragona region in Spain), taking
into account the information on receptor distribution and concentration levels of air
pollutants from the reference environmental database (IER, 1997). Table 8.22 lists
the results of the most important impacts for human health, crops and ecosystem.
According to this table, no impacts or damages are caused by heavy metal
emissions even though the inventory shows these loads in the process (Table 8.19)
because the heavy metal emissions are smaller than those manageable by the software
(Ecosense). Therefore, in the next section, environmental risk of the heavy metal
mercury emissions will be assessed to further analyze the environmental impact of
those substances.

8.4.4.2 Fate and Exposure Analysis with Risk Assessment of
Mercury for the Electricity Generation in the Industrial
Separation Process
An environmental risk procedure implies the inherent capacity of the substances to
cause negative effects and the exposition or interaction of these substances within
receptors (ecosystems or humans). These aspects are closely related to the fate
analysis and the distribution in the environment.
In order to know the fate and future exposition of mercury from the electricity
generation in the separation process, the software CalTOX described in Chapter 4
and Example 1 (Section 8.2) was applied to mercury for the area around 1000 m
from the emission source for 1 year of continuous emission.
The results of the fate and exposure assessment for mercury emissions are shown
in Table 8.23 and the following. According to this model, the concentrations on the
compartments are constant for the considered region; however, the exposure is
changing according to distance from the point of emission. (The exposure changes
proportionally at the distance of the emission.) Table 8.24 shows the exposure media
of mercury for the studied region. The daily human doses through several exposure
types were calculated based on the modeled compartments’ concentration of emis-
sions. The main exposure pathway is air inhalation. Also important is exposure
through fish ingestion.
Depending on the level of exposure, in principle adverse health effects can be
associated with all substances. In this sense, risk characterization is a dose–response
analysis that compares the current human exposure with a defined level of exposure.
On the other hand, hazard ratio expresses noncarcinogenic effects as a proportion
of an exposure intake rate and a reference dose related to the selected exposure
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pathways and chronic exposure duration (the hazard ratio for mercury is 8.25 × 10 ).
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