Page 269 - Materials Chemistry, Second Edition

4.5 Impact Categories, Impact Indicators and Characterisation Factors 253

ozone precursor in a specific (emission) region to an overall impact in the entire
impact region (here: Europe). Thus in principle with the help of POCP factors
actual impacts on humans and the natural environment can be calculated. This of
course presupposes knowledge of the emission site that is known in the case of a
factory (foreground data), but not if generic data, emissions in other continents,
and so on, are used. The results confirm the major contribution of NO and the
x
dependence of impacts on the site of emission. These facts are more important
than small variations in POCP factors (see above).
The spatial differentiation was integrated into the official Danish impact assess-
ment (EDIP2003). 224) Hauschild et al. 225) point out that the formation of ozone
(reference substance of photo smog) not only occurs at ground level but also in the
free troposphere. In this case apart from traces of NO , which are always present
x
even in relatively clean air, CO and CH are necessary. This tropospheric ozone is
4
of great importance for atmospheric chemistry and meteorology and contributes to
the greenhouse effect (see Section 4.5.2.2); however, due to smaller concentrations,
contributes less to human toxicity and ecotoxicity. The main significance of the
impact category is therefore, within a regionalised view, related to the damage of
vegetation and of human health. Two subcategories are introduced to be able to sep-
arately acquire these impacts. Regionalised characterisation factors are calculated
according to the RAINS-model, 226) which correlates the emissions (non-methane
volatile organic substance, NMVOC and NO ) of a European country to potential
x
impacts in any other (European) country. The entire impact is the result of the
sum of all relevant combinations between the model cells. Receptors are included
into the model by mapped vegetation and population density. Site-dependent char-
acterisation factors are computed and represented in a table. Since in ‘European’
LCAs many emissions of non-European countries occur or are of unknown origin
‘site-generic’ 227) characterisation factors have been suggested.
Conditions for an application of this method are:

• Sites of emissions and quantities allotted to the sites per fU for most NMVOCs 228)
and NO must be known, rare in the case of complex product systems.
x
• Characterisation factors and the model must be integrated into the software.
• It is accepted that two subcategories, vegetation and human health, are consid-
ered.
• The spatial resolution must be required by ‘goal and scope’.

If this resolution is not necessary in order to achieve the goal of the study, the effort
at present is not worthwhile yet. The method is further classified as midpoint with,
however, a certain shift towards endpoint.

224) Hauschild et al. (2006).
225) See also Kl¨ opffer, Potting and Meilinger (2001b).
226) Regionally Air Pollution Information and Simulation; Amann et al. (1999).
227) Site-generic as opposed to site-dependent.
228) CO is not designated separately.