International Review of Waste Management Policy - Department of ...

kg kg 1,4-dichlorobenzene 1,4-dichlorobenzene eq.
eq.
The allocation formula for heavy metal emissions relies on a reasonably close match
between the ‘typical’ composition data used to model the facility and the measured
emissions data. Use of the upper emissions estimate may result in an overestimation
of the annual impacts if emissions measurement were taken at a point when material
containing an exceptional amount of heavy metal was being treated.
The human toxicity impacts of the treatment options are separately assessed using a
different impact assessment method in Section 62.2, which shows how different the
results can be. That section presents the results of this additional assessment, and
highlights the limitations of the LCA approach to technology appraisal. The preceding
discussion, however, highlights how sometimes obscure pollutants, and relatively
casual assumptions made about them, can be highly influential in the assessment,
especially against toxicity impacts where impact weightings vary enormously across a
very large range of pollutants emitted / avoided. 1193
62.1.1.4 Freshwater Aquatic Eco-Toxicity
This index is similar to the human toxicity assessment described in Section 62.1.1.3,
but is intended to measure the toxicity of a chemical to aquatic life. Impacts are also
considered in terms of kg 1,4 dichlorobenzene equivalent.
Figure 62-4: Freshwater Aquatic Eco-toxicity (FAETP inf)
5.00
0.00
-5.00
-10.00
-15.00
-20.00
-25.00
-30.00
-35.00
-40.00
970
29/09/09
-0.29
Landfill Ecodeco
MBT
-34.30
Generic
Aero MBT
-24.80
Generic
AD MBT
-26.30
AD
Arrowbio
MBT
-27.70
Incin Elec
C
-15.20
Incin Elec
D
-16.20
0.23
Incin Elec
B
Incin CHP
C
-8.56
Incin CHP
G
1193 Some LCA practitioners, for this very reason, prefer to concentrate their analysis on emissions for
which data is relatively robust, rather than seeking to be ‘comprehensive’ in the range of emissions
analysed. The ‘comprehensive’ approach risks biasing the assessment for trivial reasons, such as the
fact that inventories for some processes simply do not cover the same breadth of emissions as the
inventories for others. If omitted emissions are those for which impact weightings are high, the
assessment is effectively biased.
-19.50