Environmental Engineering Reference
In-Depth Information
protein-bound form ensures security for the organism but poses increased risk for the
next member of the food chain (Gruiz, 2009c; Gruiz et al., 2009b).
The tool battery which satisfies ERA's requirements should be adapted to the spa-
tial and time-based scale of the assessment. Local, short-term risk of a point source
requires acute source management. First, the source, transport routes and receptors
must be found using assessment tools that suite to acute local processes. Then the effects
and the local receptors, e.g., the ecosystem of the target surface water, or the employee
of a workplace must be identified. Diffuse pollution with long-term, extensive pro-
cesses generally needs watershed-scale risk management with long-term monitoring,
mapping, and geographic information system-based modeling (GIS-based modeling)
(see also Chapter 10).
The expected environmental concentration of the contaminant ( PEC ) can be esti-
mated by using transport models. The PNEC or DNEL may be established as a generic
value (screening values, limiting values, intervention values or other EQCs) or as a site-
specific one, which rather depends on the endangered ecosystem or nonaverage habits
of the human land users.
Human health RA needs information on land uses and exposure parameters to
derive the human exposure from PEC . The exposure of humans through the environ-
ment is typical via inhalation of contaminated air, ingestion of contaminated drinking
water and food (plants growing in contaminated soil and animals living in a contami-
nated area) or through dermal contact and uptake from contaminated air, water and
soil. Exposure parameters quantify the human average intake and contact in different
typical scenarios (e.g., frequency and durations of stay outside and indoor, contact
time due to having a shower, surface area of the exposed skin, adherence factor on
the skin surface, the amount of water drunk per day, the amount of fish or bread
eaten on average, etc.). The exposure pathways and exposure parameters may sig-
nificantly differ for men, women and children, age groups and cultures. The no-risk
situation for humans is generally characterized by the tolerable or reference values
(concentration for inhalation and doses for ingestion and dermal contact) established
for regulatory/legislation purposes.
Some exposure factors are shown in Table 9.2. One of the most complete col-
lections of data is the handbook of exposure factors (US EPA, 2011) that contains
information on:
Ingestion of water and other liquids
Non-dietary ingestion factors
Ingestion of soil and dust
Inhalation rates
Dermal factors
Body weight
Intake of fruits and vegetables
Intake of fish and shellfish
Intake of meat, dairy products, fats
Intake of grain products
Intake of home-produced food
Total food intake
Human milk intake
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