Environmental Engineering Reference
In-Depth Information
device that produces a signal in proportion to the concentration to a defined group
of substances through a suitable combination of a selective biological system, e.g.
enzyme, antibody, membrane, organelle, cell or tissue, and a physical transmission
device (e.g. potentiometric or amperometric electrode, optical or optoelectronic re-
ceiver).
Biomarkers and Biosensors can be used as
biotest
(bioassay) which describes
a routine toxicological-pharmacological procedure for testing the effects of agents
(environmental chemicals, pharmaceuticals) on organisms, usually in the labora-
tory, but occasionally in the field under standardized conditions (with respect to
biotic and abiotic factors). In the broader sense, the definition covers cell and tissue
cultures when used for testing purposes, enzyme tests or tests using microorgan-
isms, plants and animals in the form of single-species (Fargašová
1994
) or multi-
species procedures in model ecological systems (e.g. microcosms and mesocosms).
In the narrower sense, the term only covers single-species and model system tests,
while the other procedures may be called suborganismic tests. Bioassays use certain
biomarkers or—less often—specific biosensors and can be used in bioindication or
biomonitoring.
The term tolerance can be described as desired resistance of an organism or
community by unfavourable abiotic (climate, radiation, pollution) or biotic factors
(parasites, pathogens), where adaptive physiological changes (e.g. enzyme induc-
tion, immune response) can be observed (Oehlmann and Markert
1997
). Unlike
tolerance,
resistance
is a genetically derived ability to withstand stress (Oehlmann
and Markert
1997
). This means that all tolerant organisms are resistant, but not all
resistant organisms are tolerant.
Sensitivity
of an organism or community means its
suspectibility to biotic or abiotic changes. Sensitivity is low if the tolerance or re-
sistance to an environmental stressor is high, and sensitivity is high if the tolerance
or resistance is low.
3
The MMBC-Concept
Wünschmann (
2007
) and Wuenschmann et al. (
2008
) have reported the results from
single-species tests will give only limited information on effects of chemical sub-
stances in higher biological integration levels (populations, biocoenoses or eco-
systems). Accordingly, problems even arise when just extrapolating data obtained
in one species of plant or animal to another one (even if it belongs to the same
genus); the same holds for transfer of (laboratory) test results to the freeland situa-
tion which is distinguished by more complex structures and corresponding times-
cales (Fraenzle
1993
).
Thus ecotoxicology, focussed on identifying and evaluating effects of hazard-
ous compounds on ecosystems, can only partly meet the precautionary ends of
toxicology (concerned with human health). This necessitates working on human-
based samples in the framework of a broad-viewing investigation focussed on such
effects which possibly affect humans (Markert et al.
2008
).There is a chance to
