D10: Impact of Contaminants - Hydromod

Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas
EUROLAKES
D10: Impact of Contaminants
FP5_Contract No.: EVK1-CT1999-00004
Version: 4.0
Date: 25/07/01
File: D10-vers.4.0.doc
Page 44 of 136
Environmental chemicals impairing the reproduction of animals have a great ecotoxicological
relevance because they affect the whole population and could have an effect
on the surviving of whole species. At wildlife various chronical impacts are known. They
are based on the variety of the organisms and the complex neuro-endocrine system.
The effects reach from the change of the reproduction behaviour over impacts on the
neuro-hormonical system and balance-deviations at sex hormones, the missing of sexual
cells up to sterility and sexchange. Organical compounds with high persistence belong
to the most important ecotoxicological chemicals [FENT 1998]. Examples describing
the effects of endocrine disrupters at humans and wildlife are performed in Appendix
2.
7.2 SUBSTANCES AND GROUP OF SUBSTANCES WITH A PUTATIVE
ENDOCRINE DISRUPTING ABILITY
In the following sections some special chosen substances and group of substances are
introduced. Their use and characteristics like ecotoxicologic effects and their (putative)
endocrine disrupting abilities are described. The selection based on their hazard to the
aquatic environment and humans on the one hand and the fact that they are measured
during investigation programs in the catchment areas. For the selection it was not important
if the substances have been found in concentrations being hazardous for humans
and wildlife or only in concentrations near the detection limit reps. in concentrations
being tolerated by special directives like the drinking-water directive. The decision
for acting like this was the "sneaking" hazard of this substances which have been discussed
in the previous chapters.
Heavy Metals - Use and Mode of Action
As trace elements some heavy metals are essential but in higher concentrations they
partly have toxicological effects. Heavy metals were emitted by several industrial processes,
through corrosion, in the mining and on waste dumps. Especially lead, cadmium
and mercury are regarded as being toxic. As dust, heavy metals can be transported
over a long distance through the atmosphere and reach this way waters and soil. In
aquatic environments they were diluted fast and partly they precipitate as low-soluble
carbonates, sulphates or sulphides. Therefore they accumulate in the sediments. But if
the sediment's adsorption capacity is effete the concentration in the water increases.
The cycle of the metals (air, soil, atmosphere, biosphere) strongly depends on the element's
transformation process. The biomethylation by micro-organisms has a special
importance, because metal organical compounds built in this way have a high toxicity
[DIEFENBACH].
• Copper: For all organisms copper is an essential trace element. With a yearly production
of over 7 million tonnes, copper is one of the economically most important
metals. Beside its main application area - the chemical industry - copper is also
added to dyes and pesticides (fungicides, algaecides, molluscicides). The industrial
copper input per year into the biosphere exceeds the natural input through weathering
processes nearly about three times. Just as non-essential metals, it has in
higher concentrations a toxic effect. At humans it hardly comes to damages caused
by copper but for fishes it is very toxic [KÖCK 1996].