Page 256 - Materials Chemistry, Second Edition

242 R.K. Rosenbaum et al.

organic carbonaceous materials and can make up to 50% of ambient PM concen-
trations. Respirable particles (PM 10 ) have an aerodynamic diameter less than
10 µm, coarse particles (PM 10–2.5 ) between 2.5 and 10 µm, fine particles (PM 2.5 )
less than 2.5 µm, and ultrafine particles (UFP) less than 100 nm (WHO 2006).
PM 2.5 is often referred to as the indicator that best describes the component of PM
responsible for adverse human health effects (Lim et al. 2012; Brauer et al. 2016).

10.13.2 Environmental Mechanism

Characterising health impacts from exposure to PM associated with emissions of
primary PM or secondary PM precursor substances builds on the general LCIA
framework for characterising emissions of air pollutants (see Fig. 10.2). The impact
pathway for health impacts from PM emissions is illustrated in Fig. 10.21 and starts
from primary PM emissions or secondary PM precursor substances emitted into air.
As for the toxicity impact categories, combining all factors from emission to
health impacts or damages yields the characterisation factor for particulate matter
formation (CF) with units [disease cases/kg emitted ] at midpoint level (i.e. excluding
SF) and [DALY/kg emitted ] at endpoint level:

Impact Pathway Intermediate and final LCIA output metrics

Mass emitted to air
[kg PM or precursor emitted]
Fate factor
Intake fraction
[day]
Time-integrated mass in air [kg PM inhaled/
[kg PM in air day] kg PM or pre-
Exposure factor cursor emitted] Characteri-
[1/day] sation factor
Mass inhaled [DALY/kg PM
[kg PM inhaled]
or precursor
Effect factor
emitted]
[cases/kg PM
Disease incidences inhaled] [DALY/kg PM
[cases] inhaled]
Severity factor
[DALY/case]
Human health impacts
[Disability-adjusted life years, DALY]

Fig. 10.21 Schematic impact pathway and related output metrics for characterising health impacts
from particulate matter (PM) exposure in life cycle impact assessment [adapted from Fantke et al.
(2015)]