ILCD Handbook: Framework and requirements for LCIA models and ...

ILCD Handbook: Framework and requirements for LCIA models and indicators First edition
3.1 Human Health
3.1.1 Recommendations
For impacts on Human Health caused by various types of environmental stressors, the
aim is to quantify the changes in both mortality and morbidity that are associated with goods
or services in an integrated way. For human endpoint indicators, the focus is on the
integration of various stressors towards a common endpoint for Human Health 8 . In this
context, aggregated Human Health indices are of particular importance.
The DALY-concept (Disability Adjusted Life Years) combines information on quality of life
and life expectancy in one indicator, deriving the (potential) number of healthy life years lost
due to premature mortality or morbidity. Morbidity is weighted for the severity of the disorder
(Murray and Lopez, 1996). The QALY concept (Quality Adjusted Life Years) can be
considered similar to the DALY.
As the focus of the LCIA method recommendations is on Human Health impacts due only
to stressors, the DALY is selected as the most appropriate metric for the Area of Protection
Human Health. The use of the DALY-concept is recommended including years of life lost for
mortality and years of life disabled for morbidity, without age weighting and discounting.
3.1.2 Background and Discussion
For Human Health, the aim is to provide indicators, in terms of both mortality and
morbidity, for the effects caused by various types of stressors. Aggregate Human Health
indicators are of particular relevance. As indicated by McAlearney et al. (1999) and Gold et
al. (2002), well-known concepts are Quality Adjusted Life Years (QALY) and Disability
Adjusted Life Years (DALY).
The QALY-concept combines both the quality and quantity elements associated with
Human Health in one indicator to express the total health benefits of various healthcare
programs in common units (Weinstein and Stason, 1977). The DALY-concept was first
introduced by Murray and Lopez (1996) as part of the Global Burden of Disease study. The
DALY-concept similarly combines information on quality and quantity of life in one indicator,
deriving the (potential) number of healthy life years lost due to premature mortality or
morbidity. In fact, as argued by Weidema (2006, 2008), the change in measurement unit
QALY can be considered identical to the change in DALY, except for a reversal of signs
(∆QALY=−∆DALY).
Morbidity is weighted in terms of the severity of the disorder. For example, if a person gets
lung cancer at the age 62 and consequently suffers for 5 years before dying, an estimation of
both the severity of her suffering from lung cancer and information on the life expectancy in
the absence of the cancer is required.
As the focus of LCIA is on Human Health impacts and not Human Health benefits, the
DALY is selected as the most appropriate indicator. Its use and associated assumptions are
discussed in more detail in the following sub-sections.
8 The following midpoint impacts are considered to contribute to damages on Human Health, although
the contribution has not been modelled completely by all the recommended methods: climate change,
ozone depletion, human toxicity, respiratory organics, ionising radiation and photochemical ozone
formation
3 Requirements for Areas of Protection 16