Management of abandoned and contaminated land - Environmental Deterioration and Contamination: Problems and their Management - page 184

Another disadvantage of this concept is the too high requirement compared with
the general state of groundwater in the country. A dynamic approach, which would
be needed, for example, for the acceptance of natural attenuation as a risk reducing
process, can hardly be integrated into a static concept based on groundwater quality.
The background of the concept that focused on groundwater is that groundwater
is a (potential) product—extracted, sold and used for drinking, bathing, irrigation and
other agricultural and industrial purposes—which has a price, so that it is easy and
evident to consider it as a value, created/derived from its benefit. This materialistic or
financial approach can hardly be applied to the protection of the soil ecosystem and its
services, which attributes equal importance to groundwater but does not monetize it,
and if it were—as some protected species have a theoretical value—it would not be of
benefit or loss to concrete owners, but to the entire mankind, which is not a motivating
factor in our presently dominating political and social structures. Agricultural fields
are in a somewhat better situation than natural land because the quality and part of
the soil services can be quantified and qualified by their production. In this sense, soil
(the upper part of soil used for agricultural production) can also be considered as a
good to be sold to consumers, the value and marketability of which may be limited
by its contamination. A further step in this direction is the obligation that the fact of
contamination should be registered in the land tenure or property register.
Groundwater has an important role in the conceptual model of a contaminated
site: it is a special part of the soil: it is mobile, flows under the ground in the pores of the
solid soil phase and transports soil contaminants over large distances from the source.
Groundwater differs from surface water by being invisible, less or not at all aerated,
and being in intensive interaction with the solid phase, which results in partitioning of
the dissolved and sorbed components in the soil. Groundwater also differs from soil
moisture, creating a continuous layer and filling soil pores completely.
Plants grown on soil are central targets of risk management aiming to ensure ben-
eficial and safe agricultural production and to avoid secondary poisoning posing a
hazard to humans and ecosystem. The chemicals accumulated in plants are the per-
sistent and bioaccumulative ones, being frequent participants on the priority lists.
Biomagnification, a threat from gradual bioaccumulation along food chains, may
cause multiple exposures for predators at the top of food chains compared with direct
exposure to soil.

5.2 Risk assessment of contaminated land
Risk is a potential negative effect to an asset. Quantitative risk means the magnitude of
risk: probability of the incidence multiplied by the estimated size of the occurred/caused
damage. The size of the potential damage can be characterized by the risk character-
ization ratio ( RCR PEC/PNEC or D/ADI ), which is the quotient of the predicted

environmental concentration ( PEC ) and the predicted no effect concentration ( PNEC ),
which probably does not affect the ecosystem adversely. For human receptors the dose
of contaminant per person taken in daily ( D ) is calculated from the environmental
concentration by human exposure parameters such as inhaled air/day or consumed
water and food (fish, vegetable, etc.), dermal contact and uptake, soil ingestion, etc.
The acceptable daily intakes ( ADI s) are screening values, limit values, permitted levels,
based on animal tests or epidemiological results (see in detail in Volume 2).

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