Environmental risks and impacts - Environmental Deterioration and Contamination: Problems and their Management - page 203

Figure 8.6 Environment-specific risk management is based on the relative scale of impacts.

social and economic impacts may put high burdens on humans. Similar examples can
be cited for the environment: the ecosystem of soil is impacted by many chemicals, both
contaminants and non-contaminants. Contaminants are partly biodegraded and uti-
lized after adaptation by the living organisms, partly accumulated in toxic or non-toxic
forms. At the same time, soil deteriorating processes are going on, which impact the
ecosystem that uses the soil services such as food provision and habitats. Pests, inva-
sions, airborne effects, meteorological extremities and other non-quantifiable impacts
are not included in chemical risks, although, in realty, they arise together.
Environmental risk management should handle the potential impacts instead of
the damage already occurred to be able to prevent the targeted environment and recep-
tors. Environmental risk is quantified as the probability of the damage multiplied by
the estimated size of the damage. The probability of the damage is often measured by
the so-called risk characterization ratio (RCR), which, for example, is the ratio of the
amount of contaminants taken in with drinking water or food by humans to the accept-
able (not being toxic or otherwise harmful) amount (RCR

daily intake/acceptable
intake), or for ecosystems RCR is the ratio of predicted environmental concentration
to no effect concentration.
Impact assessment should cover all significant components; the potential adverse
effects related to the assessment's target. This is where we face the first problem of
subjectivity and the possibility of errors when selecting the impacts. The second prob-
lem to solve is the summation or the weighted summation (using weighting factors)
of the impacting factors. The creation of additive values is generally based on the

=