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PAPER
8
Ecotoxicological risk of Endocrine Disruptors to marine top predators
Dr. Maria Cristina Fossi*, Silvia Casini** and Letizia Marsili**
,*Department of Animal Biology and Marine Ecology, University of Messina,Italy,
**Department of Environmental Science, University of Siena, Italy
The aim of this presentation is to describe the potential use of biomarkers
as diagnostic and prognostic tools for wildlife risk assessment, especially
with regard to endocrine-disrupting chemicals (EDCs). Endocrine-disrupting
chemicals are commonly defined as exogenous substances (such as certain
herbicides, fungicides, insecticides and industrial chemicals) that
cause adverse health effects in an intact organism or its progeny
as a consequence of changes in endocrine functions. The alarm sounded
recently by several research commissions and regulatory agencies underlines
the necessity of developing diagnostic and prognostic tools to identify
exposure to and the effects of these contaminants in man and wildlife.
Exploring the problem of EDCs from the ecotoxicological point of view
it is well known that EDCs such as polyhalogenated aromatic hydrocarbons
(PHAHs) and toxic metals tend to be biomagnified in the terrestrial
and in the marine food chains. Top predators, particularly in the
Mediterranean environment, therefore accumulate high concentrations
of these contaminants and become subject to high toxicological risk.
In this presentation we illustrate the need to develop sensitive biomarker
techniques for the detection of toxicological risk of marine top predators
(Xiphies gladius, Thunnus thynnus thynnus) and particularly nondestructive
techniques, such as nondestructive biomarkers, for the hazard assessment
and protection of endangered species exposed to EDCs, such as marine
mammals. The potential estrogenic effects of polyhalogenated aromatic
hydrocarbons on Mediterranean commercial fish species, the top predators
(Xiphies gladius, Thunnus thynnus thynnus) are recently investigated
using Vitellogenin (VTG) and Zona Radiata Proteins (ZPR). High level
of induction of VTG and ZRP are detected in adult males of Xiphies
gladius, suggesting the high toxicological risk to which these species
are exposed in the Mediterranean environment. In this paper we also
explored the potential use of BPMO (MFO) activity in skin biopsies
of marine mammals as indicator of exposure to EDCs such as organochlorines.
Since several marine mammal species tend to accumulate high concentrations
of anthropogenic contaminants (such as organochlorines and heavy metals),
the development of nondestructive techniques for their hazard assessment,
protection and conservation is strongly recommended. An interesting
statistical correlation was found between BPMO activity and organochlorine
levels in skin biopsy specimens from males of Balaenoptera physalus.
Among the organochlorines detected, PCBs, op'DDT and op'DDE are known
environmental estrogens and pp'DDE and pp'DDT are known antiandrogens.
A statistical correlation (Spearman Test p<0.05) was also found between
BPMO activity and organochlorine levels (DDTs) in skin biopsy specimens
of the endangered Mediterranean population of Delphynus delphis. These
results suggest that BPMO induction may be an early warning sign of
exposure to EDCs such as OCs and a potential alert of transgenerational
effects, related to exposure of future generations via the placenta
and milk.
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