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 2 of 136
1 EXECUTIVE SUMMARY
Water is on one hand an irreplaceable and life-supporting element of all life, not only
human, but plant and animal life as well, and of ecosystems as a whole. Undeveloped
and unpolluted wetlands, in turn, are the single most important precondition for the
protection of biodiversity. On the other hand water is also valued as a resource. Surface
and groundwater have manifold economic uses, be it for industry, agriculture, shipping,
mining and many others, and of course as a source of drinking water.
Therefore any water management initiative should be founded as complete as possible
on a understanding of the water resource system to which it applies. Water is first of all
a natural resource and the sustainable management of that resource calls for an improved
understanding of the aquatic ecosystems. Water is a resource which is essentially
best managed at local water basin level but there are common grounds in water
resource development across Europe, and numerous interactions – environmental, as
well as socio-economic – are well beyond the scope of action taken at the local or regional
level. This leads to a call for European directives and frameworks to guide management
decisions at the various levels.
This report of the European Fifth Framework Programme project EUROLAKES summarises
the impacts of contaminants on aquatic ecosystems with respect to great deep
lakes and, while the more obvious signs of water pollution, fish kills and foam floating
on the surface, are fortunately seldom encountered in European lakes today, more
subtle biological effects have been the focus of this study. Trace quantities of endocrine
disrupting chemicals, for instance, have been shown to interfere with the hormone
regulation of fish and molluscs, leaving them infertile. Hazardous chemicals such as
these may be made responsible for declining fish catches in several European countries,
yet the exact mechanisms of action are extremely difficult to identify. Only a precautionary
approach preventing the continued release of potentially hazardous substances
into the environment can solve this problem.
Endocrine disrupting chemicals (EDCs) have caused particular concern because they
may interfere with the normal function of the hormonal systems also of humans. Endocrine
disrupting properties are found in several classes of chemicals released into the
environment such as some insecticides and fungicides, some phthalate plasticizers, dioxins
and anti-fouling paints. Speculation has linked exposure to EDCs to a range of
effects in humans and animals from falling sperm counts to increases in testicular cancer
all of which has fuelled public concern. Humans are exposed daily to chemicals that
have been shown or suggested to have hormone-disrupting properties. Speculation has
linked this to a range of disorders. Whilst high levels of exposure to some EDCs could
theoretically increase the risk of such disorders, no direct evidence is available at present.
Trends in the incidence of some of these disorders are difficult to discern and,
when they are found, are difficult to interpret because of inconsistencies in method.
EDCs are but one of a variety of potential risk factors, both environmental and genetic.
Despite the uncertainty, it is prudent to minimise exposure of humans, especially pregnant
women, to EDCs.