Environmental Engineering Reference
In-Depth Information
Table 9.2
Age-dependent exposure factors for water and soil ingestion and dermal contact.
Intake
Intake
Surface
Absorbed
Body
Exposure
Exposure
rate
rate
Dermal
area of
fraction,
weight
frequency
duration
water
soil
adherence
exposed skin
dermal
Age
(kg)
(days/year)
(years)
(L/day)
(mg/day)
(mg/cm
2
)
(cm
2
)
(-)
0-1 month
3.3
350
0.08
1.0
200
0.2
2,625
0.13
1-3 months
4.1
350
0.17
1.0
200
0.2
2,625
0.13
3-6 months
5.7
350
0.25
1.0
200
0.2
2,625
0.13
6-12 months
9.2
350
0.5
1.1
200
0.2
2,625
0.13
1-2 years
11.2
350
1
0.9
200
0.2
2,571
0.13
2-3 years
13.1
350
1
0.9
200
0.2
2,434
0.13
3-6 years
17.1
350
3
1.1
200
0.2
3,107
0.13
6-11 years
27.6
350
5
1.2
100
0.2
3,408
0.13
11-16 years
48.6
350
5
1.8
100
0.1
4,814
0.13
16-21 years
63.2
350
5
2.3
100
0.07
5,655
0.13
21-30 years
70
350
9
2.9
100
0.07
5,700
0.13
•
Activity factors
•
Consumer products
•
Lifetime
•
Building characteristics.
Regional RA considers point and diffuse sources, and calculates environmental
concentrations and risks for larger areas, e.g., at watershed scale. Remote sensing,
GIS-based mapping and transport modeling are preferable for the site assessment (see
Chapter 10). Special statistical tools should deal with spatial deviations. The results
of the models should be validated by measured data. RA and risk management need
concerted action by stakeholders in the area.
The global risks posed by chemical substances in products, during their period
of use and the waste phase can be characterized by qualitative or quantitative tools.
Quantitative ERA may be based on global concentration estimates or measured values
of a contaminant (e.g., chlorinated hydrocarbons or methane and CO
2
in the atmo-
sphere, or pH of surface waters and soils), the results of such an assessment is a
RCR
,
similar to the local or regional ERA. On the other hand, a number of global impacts
cannot be characterized quantitatively or summarized, which requires relative scales
as normalization tools. LCA is a semiquantitative tool, which is applicable for some
globally occurring adverse effects, such as greenhouse effects, ozone depletion, use of
nonrenewable resources, or loss of biodiversity.
Former risk management approaches handled ecological and human risks sepa-
rately; but today, due to the exclusion of animal testing, the two come closer and
“environmental risk'' integrates ecological and human health risks. From the results of
“environmental toxicity testing,'' using non-animal test systems one can extrapolate
to both ecological and human receptors using different extrapolation tools.
The effects of chemical substances on the ecosystem (as a whole) and humans (as a
whole) cannot be directly measured. Instead, extrapolation from environment-relevant
biological models, indicator species or biomarkers is used. Mathematical tools such as
Search WWH ::
Custom Search