the monitoring of organic pollution by endocrine disruptors in European surface
waters [8] and were also implemented in the PIREN-Seine programme for the
evaluation of the Seine River quality. Only data of oestrogenic activities are
presented, given their ubiquity and levels in both the water column and sediments.
2.1 In Vitro Endocrine Disruptor Bioassays in Water
Contamination Monitoring
The oestrogenicity of the organic contamination of surface waters collected
over nine campaigns between February and November 2010 at Marnay-sur-Seine,
Bougival and Triel-sur-Seine was studied using the MELN reporter gene assay
according to [11]. Regardless of the sampling location, surface waters showed
significant oestrogenic-mimetic activities, on the order of 1 ng E2-eq/L
1 : median
EEQ
1 values of 0.27, 0.40 and 0.51 ng E2-eq/L were measured for Marnay-surSeine, Bougival and Triel-sur-Seine, respectively [12]. Similar oestrogenic activity
levels were reported under the PIREN-Seine programme for organic contamination
of rivers sampled in the Orge catchment area near Paris during September 2007
[13]. Both mean and median EEQ values were the lowest for Marnay-sur-Seine
and the highest for Triel-sur-Seine. The data tended to highlight an upstream–
downstream gradient of increasing oestrogenic activity in the Seine River:
Marnay-sur-Seine < Bougival < Triel-sur-Seine, even if temporal variations due
to hydrologic conditions may mask the increasing gradient when the results are
averaged over the year. Indeed, the strongest mean oestrogenic activity was observed
for Bougival water sampled in July [12], corresponding to the low-flow period.
The same general pattern was shown for Triel-sur-Seine. In contrast, the lowest
oestrogenic activities were detected in winter, highlighting a dilution of water
contamination during high-flow periods. Overall, the cellular bioassay implemented
made it possible to monitor the Seine River contamination by bioactive chemicals at
the oestrogenic axis, in accordance with both seasonal and spatial expected distribution of pollution.
2.2 Comparison of In Vitro Bioassays to Chemical Analysis
in Water Contamination Monitoring
The in vitro bioassays may be used alone or in combination with chemical analysis to
monitor the aquatic contamination by endocrine disruptors. In the framework of the
1 The transcriptional activities measured using in vitro ED bioassays are generally expressed as
17β-estradiol (E2) equivalent (eq) quantity (EEQ), in ng E2-eq/L of water or in ng E2-eq/g of
sediment, by comparing them with the activity of the specific hormonal ligand E2.
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M. Bonnard et al.
waters [8] and were also implemented in the PIREN-Seine programme for the
evaluation of the Seine River quality. Only data of oestrogenic activities are
presented, given their ubiquity and levels in both the water column and sediments.
2.1 In Vitro Endocrine Disruptor Bioassays in Water
Contamination Monitoring
The oestrogenicity of the organic contamination of surface waters collected
over nine campaigns between February and November 2010 at Marnay-sur-Seine,
Bougival and Triel-sur-Seine was studied using the MELN reporter gene assay
according to [11]. Regardless of the sampling location, surface waters showed
significant oestrogenic-mimetic activities, on the order of 1 ng E2-eq/L
1 : median
EEQ
1 values of 0.27, 0.40 and 0.51 ng E2-eq/L were measured for Marnay-surSeine, Bougival and Triel-sur-Seine, respectively [12]. Similar oestrogenic activity
levels were reported under the PIREN-Seine programme for organic contamination
of rivers sampled in the Orge catchment area near Paris during September 2007
[13]. Both mean and median EEQ values were the lowest for Marnay-sur-Seine
and the highest for Triel-sur-Seine. The data tended to highlight an upstream–
downstream gradient of increasing oestrogenic activity in the Seine River:
Marnay-sur-Seine < Bougival < Triel-sur-Seine, even if temporal variations due
to hydrologic conditions may mask the increasing gradient when the results are
averaged over the year. Indeed, the strongest mean oestrogenic activity was observed
for Bougival water sampled in July [12], corresponding to the low-flow period.
The same general pattern was shown for Triel-sur-Seine. In contrast, the lowest
oestrogenic activities were detected in winter, highlighting a dilution of water
contamination during high-flow periods. Overall, the cellular bioassay implemented
made it possible to monitor the Seine River contamination by bioactive chemicals at
the oestrogenic axis, in accordance with both seasonal and spatial expected distribution of pollution.
2.2 Comparison of In Vitro Bioassays to Chemical Analysis
in Water Contamination Monitoring
The in vitro bioassays may be used alone or in combination with chemical analysis to
monitor the aquatic contamination by endocrine disruptors. In the framework of the
1 The transcriptional activities measured using in vitro ED bioassays are generally expressed as
17β-estradiol (E2) equivalent (eq) quantity (EEQ), in ng E2-eq/L of water or in ng E2-eq/g of
sediment, by comparing them with the activity of the specific hormonal ligand E2.
246
M. Bonnard et al.