Two main strategies have been used in the PIREN-Seine programme for a decade in
order to characterise the ecotoxicological status of the Seine waterbodies. The first
one has consisted in an ex situ strategy with the development of complementary
bioassays performed on cell cultures and/or laboratory model organisms to investigate the (eco)toxicity of environmental samples. In particular, the study of the
oestrogenic potential of water and sediment samples using specific in vitro bioassays
is illustrated in this chapter (see Sect. 2). The second strategy consisted in in situ
measurements of various biological responses, called biomarkers, to reflect the
impacts on sentinel species. This approach is illustrated here with examples of
studies conducted on (1) field populations for fish species, i.e. passive biomonitoring, and (2) transplanted organisms for aquatic invertebrates such as mussels
and crustaceans, i.e. active biomonitoring (see Sect. 3). Most of these ecotoxicological studies investigated three pilot sites of the Seine River, upstream and downstream of the Paris agglomeration (i.e. Marnay, Bougival and Triel-sur-Seine) and,
more episodically, sites on the Orge River, an important tributary of the Seine River.
Experience gained from all these studies allowed establishing reference and threshold values for many biological endpoints. They now can be combined with chemical
measurements within integrated models (i.e. the Weight of Evidence [WOE]
approach; see Sect. 4) generating a global index of waterbody pollution.
2 Value of In Vitro Bioassays for an Ex Situ Evaluation
of Water Contamination: The Case of Endocrine
Disruptors
Among pollutants discharged into the environment, many belong to the family of
endocrine disruptors (EDs), chemicals able to lead to endocrine disorders in both
humans [4] and wildlife [5], even at trace levels. Polychlorinated biphenyls (PCBs),
polybrominated diphenyl ethers (PBDEs) and phthalates are such chemicals, which
have been quantified both in water and the roach Rutilus rutilus in the Seine basin
[6]. The main ED disorders may affect the oestrogenic pathway of aquatic species
and induce the ‘feminisation’ of male fishes in some cases [7]. However, aquatic
contaminants may target other endocrine axes. Among the endocrine-disrupting
effects affecting oestrogenic, androgenic or thyroid endpoints, the most pronounced
effects of aquatic contamination were oestrogenicity, as brought to light by a
European research programme [8]. In this context, in vitro bioassays applied for
endocrine disruptors [9, 10] are a good compromise between in situ bioassays, which
can be expensive and time- and animal-consuming, and hence not suitable as highthroughput screening tools, and chemical analyses, which are limited to a restricted
number of quantified pollutants and do not allow one to consider their harmful
effects in mixtures representative of an in situ exposure. In vitro bioassays can
therefore be considered as intermediate sensitive and global screening tools for
monitoring aquatic ED contamination, to assess its intrinsic dangerousness because
they integrate interaction effects (additive, antagonistic or synergistic) between low
doses of chemicals (cocktail effects). Such in vitro cellular bioassays were used for
Experience Gained from Ecotoxicological Studies in the Seine River and. . .
245
order to characterise the ecotoxicological status of the Seine waterbodies. The first
one has consisted in an ex situ strategy with the development of complementary
bioassays performed on cell cultures and/or laboratory model organisms to investigate the (eco)toxicity of environmental samples. In particular, the study of the
oestrogenic potential of water and sediment samples using specific in vitro bioassays
is illustrated in this chapter (see Sect. 2). The second strategy consisted in in situ
measurements of various biological responses, called biomarkers, to reflect the
impacts on sentinel species. This approach is illustrated here with examples of
studies conducted on (1) field populations for fish species, i.e. passive biomonitoring, and (2) transplanted organisms for aquatic invertebrates such as mussels
and crustaceans, i.e. active biomonitoring (see Sect. 3). Most of these ecotoxicological studies investigated three pilot sites of the Seine River, upstream and downstream of the Paris agglomeration (i.e. Marnay, Bougival and Triel-sur-Seine) and,
more episodically, sites on the Orge River, an important tributary of the Seine River.
Experience gained from all these studies allowed establishing reference and threshold values for many biological endpoints. They now can be combined with chemical
measurements within integrated models (i.e. the Weight of Evidence [WOE]
approach; see Sect. 4) generating a global index of waterbody pollution.
2 Value of In Vitro Bioassays for an Ex Situ Evaluation
of Water Contamination: The Case of Endocrine
Disruptors
Among pollutants discharged into the environment, many belong to the family of
endocrine disruptors (EDs), chemicals able to lead to endocrine disorders in both
humans [4] and wildlife [5], even at trace levels. Polychlorinated biphenyls (PCBs),
polybrominated diphenyl ethers (PBDEs) and phthalates are such chemicals, which
have been quantified both in water and the roach Rutilus rutilus in the Seine basin
[6]. The main ED disorders may affect the oestrogenic pathway of aquatic species
and induce the ‘feminisation’ of male fishes in some cases [7]. However, aquatic
contaminants may target other endocrine axes. Among the endocrine-disrupting
effects affecting oestrogenic, androgenic or thyroid endpoints, the most pronounced
effects of aquatic contamination were oestrogenicity, as brought to light by a
European research programme [8]. In this context, in vitro bioassays applied for
endocrine disruptors [9, 10] are a good compromise between in situ bioassays, which
can be expensive and time- and animal-consuming, and hence not suitable as highthroughput screening tools, and chemical analyses, which are limited to a restricted
number of quantified pollutants and do not allow one to consider their harmful
effects in mixtures representative of an in situ exposure. In vitro bioassays can
therefore be considered as intermediate sensitive and global screening tools for
monitoring aquatic ED contamination, to assess its intrinsic dangerousness because
they integrate interaction effects (additive, antagonistic or synergistic) between low
doses of chemicals (cocktail effects). Such in vitro cellular bioassays were used for
Experience Gained from Ecotoxicological Studies in the Seine River and. . .
245