Biomedical Engineering Reference
In-Depth Information
Emissions into compartment m
Transport
Transport
and fate
factor
and fate
(environm.
residence
time)
Fraction transfer red to comp. n
Intake
fraction
iF
Time integrated mass in comp. n
Body
burden
factor
Human
exposure
Concentr.-
response
Species
exposure-intake
Dose taken in
Uptake and
residence
time in
humans
Effect
factor
Potency
(Dose-
response)
Dose absorbed
Body burden
Effect
factor
Potentially affected
fraction of species
Risk of affected
persons
Impacts on
ecosystems
Impacts on
human health
h
FIGURE 11.9
Framework for human toxicity and ecotoxicity of chemicals and nanoparticles. (Extended from
Jolliet, O. et al.,
Int. J. Life Cycle Assess.
,
11,
1 3 7,
20 06.)
increase in the affected fraction of species due to an emission into a specific
compartment, expressed as PAF m
3
d/kg
emitted
. As described by Henderson
et al.,
105
the characterization factors can be expressed as the multiplica-
tion of four factors. The first three terms describe the transport and expo-
sure of a substance: the fraction transferred from emission compartment
i
to freshwater (
f
i
,w
, [-]), the environmental fate factor in freshwater (FF
w,w
,
[kg
in water
/( k g
emitted
/d) = d]), and the exposure factor, that is, the dissolved and
bioavailable fraction (XF
w
, [-]). The final term, the effect factor, based on eco-
toxicological tests, describes the ecotoxicological response from freshwater
ecosystems (EF
w
, [PAF m
3
/kg
in water
]):
freshwater ecotox
CF
=
f
FF
XF
EF
(11.3)
i
i
,w
w,www
11.3.3.2 Fate and Exposure to Nanoparticles
Determination of physico-chemical properties:
Since nanoparticles can
widely vary across nanoproducts and therefore vary their behavior in the
environment and in the body, it is crucial to have them properly character-
ized see Chapter 7, present edition, in terms of size distribution, surface
chemistry, shape, functionalization, and optical properties. Since these prop-
erties might be changed by aging, physical or chemical interaction with other
particles, substances, or solids, characterizing these is even more critical as a
basis for any evaluation and modeling of their behavior and dose-response
