Page 95 - Materials Chemistry, Second Edition

LIFE CYCLE IMPACT ASSESSMENT 77

Endpoint effects
not calculated or
which do not
DAMAGE indicator may aggregate have damage
all calculated endpoint effects indicators are
into single unit. lost
^ y
Figure 4.5 Progression from inventory flows to damage for human health. Note that endpoints
not included in the damage indicators are lost (Bare and Gloria 2006).

it may be relatively easy to quantify some impacts (e.g., malaria),
other impacts (e.g., the impact on biodiversity) may not be so eas-
ily quantified and thus may be lost.
3. Intermediary steps should be made explicit and reported sepa-
rately. For example, if number of cases, Years of Life Lost (YLL)
and Years of Life Disabled (YLD) are utilized then these should
be considered first separately for impacts on human health.
Disability weighting could then be explicitly considered if desired
to group diseases together to arrive to DALY.
4. All modeling (midpoint and damage) should be properly docu-
mented on data and modeling uncertainty and reliability. Value
choices should be made explicit and properly documented
(implicit and explicit in midpoint and damage modeling). As
a matter of fact, it is important to be more specific about these
values choices to decrease the uncertainty. There is no unique uni-
versal set of values.

In the end, LCIA approaches are typically viewed along one of two families:
classical methods that determine impact category indicators at an intermedi-
ate position of the various impact pathways (e.g. ozone depletion potential) or
damage-oriented methods that aim to present results in the form of damage
indicators at the level of an ultimate societal concern (e.g. harm to human health).