Page 185 - Materials Chemistry, Second Edition

170 LIFE CYCLE ASSESSMENT HANDBOOK

emission results; these results may further change, especially in comparative
studies, if one uses different methods of impact assessment.
Furthermore, another problem regards the phase of impact assessment and,
in particular, the existence of characterization factors of the pesticide used:
whether a characterization factor for a given pesticide exists or not could enor-
mously change the results of an LCA study.
Similar considerations can be made to estimate emissions from the use of
fertilizers; in particular referring to the emissions of N 2 0, NH 3, N0 3 - to air,
due to the use of nitrogen fertilizers, and of nitrate and phosphate leaching
to the groundwater, due to the use of nitrogen and phosphorus fertilizers.
The current extremely large variety of dispersion models and literature data
(Brentrup, et al. 2000; ECETOC, 1994; Houghton, 1997) has created numerous
approaches used by LCA scholars. Hence there is no current methodological
standardization and it is therefore advisable to associate the LCA being carried
out with a sensitivity or an uncertainty analysis in order to obtain a compre-
hensive picture of the overall results.

7.2.4 Land Use and Water Use Impact Categories
The increase in world population is causing the agri-food sector to make use
of an ever growing quantity of freshwater and land in terms of pasture land,
cropland, industrial space and relative infrastructures. This increase in land
and water use, inevitably, greatly influences the ecosystem. Initial approaches
to the study of land use and water use in conjunction with LCA were devel-
oped over a decade ago (Lindeijer, 2000; Lindeijer, 2000; Lindeijer, et al. 2002;
Müller-Wenk, 1998; Owens, 2002). Current methodologies dealing with these
impact categories are still not fully representative of all the problems and
aspects that can be encountered. As a consequence such methods need to be
tailored and revised according to the agri-food product being considered dur-
ing the LCA.

7.2.4.2 Land Use
The simplest way for LC As of food products to evaluate the impact of land use
is to consider only the area occupied (Schmidt, 2008; Goedkoop, et al. 2009);
however, in order to get a better picture of all environmental aspects, impacts
on the quality of the soil (Saad, et al. 2011) or biotic potential and quality of
the landscape (Mattsson, et al. 2000) should also be considered. The nature of
these impact categories implies a difference in data type in terms of qualitative
(e.g. biodiversity) versus quantitative (e.g. soil quality) data. There are there-
fore many kinds of land occupation/transformation indicators and no clear
cut generally applicable impact methodology. Hence, it can be difficult to fully
represent the sustainability of agri-food product systems.
"Midpoint Approach" indicators in general focus on soil quality indicators
e.g. soil pH, phosphorous soil content etc. (Mattsson, et al. 2000), and are suited
for comparisons between different land use activities. Soil Organic Matter