1. * e-mail: antonio.diguardo@uninsubria.it
European environmental scenarios of chemical bioavailability in freshwater systems
Melissa Morselli1, Giuseppe Morabito2, Paul Van den Brink3, Frederik De Laender4, and Antonio Di Guardo1 *
1 Department of Science and High Technology, University of Insubria, Como, Italy
2 National Research Council, Institute for Ecosystem Study, Verbania-Pallanza, Italy
3 Wageningen Environmental Research (Alterra), Wageningen, The Netherlands
4 Department of Aquatic Ecology and Water Quality Management, Wageningen University, The Netherlands
5 University of Namur, Research Unit in Environmental and Evolutionary Ecology, Belgium *
SETAC Brussels, May 11th, 2017

2. Presentation outline 1. Framework and objectives
2. Exposure model: ChimERA fate
 Model background
 Improvement (phytoplankton, detritus and DOM dynamics)
3. Scenario development
4. Results
 Scenario description
 Bioavailable concentrations in the different scenarios
5. Conclusions and ongoing work

3. Models Environmental Risk Assessment
Framework and objectives (1)
Models
Environmental Risk Assessment
Many chemicals + ecosystem complexity
 simple standardized models
Exposure
 Steady-state models
 Constant chemical emissions
 Static scenarios (no environmental-ecological dynamics)
Simplicity, low amount of input data
Lack of ecological realism and relevance
Optimize this slide to drive the reader (maybe integrate slide 3 and 4)
Among the new challenges for ERA:
more dynamic and realistic models and scenarios…

4. Framework and objectives (2)
Evidences
General lack of data concerning environmental/ecological dynamics
Issues
Sampling campaigns to produce data with high temporal and spatial resolution are often expensive and difficult to carry out
Variability of exposure concentrations (environmental heterogeneity)
Importance of including temporal dynamics of biomass and organic phases in models and scenarios
5 realistic environmental scenarios for shallow water bodies representative of different European conditions
Temporal profiles of water temperature + autochthonous phytoplankton biomass, detritus and dissolved organic matter
Optimize this slide to drive the reader (maybe integrate slide 3 and 4)

5. Exposure model: ChimERA fate (1)
Chemical emission
Det
DOM
Contaminatedsediment
Background *
Model unit
Compartments/sub-compartments: water, sediment, detritus, dissolved organic matter (DOM), macrophytes
Layered sediment
Output: hourly chemical concentrations in all compartments + chemical fluxes
* Morselli et al. (2015) Sci Total Environ 526,

6. Exposure model: ChimERA fate (2)
Background *
Spatialization
Chemical emission
Simplified pond (side view)
Optional, simply shows spatialization
* Morselli et al. (2015) Sci Total Environ 526,

7. Exposure model: ChimERA fate (3)
Improvements *
Chemical emission
Det
DOM
Contaminatedsediment
Mention model evaluation for phytoplankton
Phytoplankton compartment included (exchanging chemical with water) **
Ordinary differential equations (ODEs) included to calculate temporal profiles of phytoplankton biomass, detritus and dissolved organic matter (DOM) concentrations
* Di Guardo et al. (2017) Sci Total Environ 580,
** Del Vento and Dachs (2002) Environ Toxicol Chem 21(10),

8. Exposure model: ChimERA fate (4)
Improvements *
ODEs
Phyto **
Det **
Solved simultaneously with chemical mass balance
(5th-order accurate, diagonally implicit Runge-Kutta with adaptive time stepping)
Brief overview of equations, without going into details
DOM ***
* Di Guardo et al. (2017) Sci Total Environ 580,
** De Laender et al. (2015) Environ Int 74,
*** De Laender et al. (2008) Chemosphere 71,

9. Scenario development (1)
5 realistic scenarios for meso-eutrophic, lowland, shallow water bodies located at different latitudes
Temporal (annual) profiles of water temperature, phytoplankton biomass, detritus and DOM concentration
Data from a reference water body + ODE parameterization
Scandinavia UK
Central Europe
Northern Italy
Mediterranean

10. Scenario development (2)
Ref. water body
Lake Candia
Piedmont Region, Northern Italy
Meso-eutrophic small (1.26 km2) and shallow lake (avg. depth 4.7 m)
Data available for all the parameters of interest
Measurements performed at least on a monthly basis for years

11. Results: scenario description
Temperature
Detritus 30
0.7 25
0.6
0.5 20
T (°C)
0.4 15
Detritus (mg C L-1)
0.3 10
0.2 5
0.1
Phytoplankton
DOC 8 4 7
3.5 6 3 5
2.5
Biomass (mg w.w. L-1) 4
DOC (mg C L-1) 2 3
1.5 2 1 1
0.5 J F M A M J J A S O N D J F M A M J J A S O N D
Mediterranean
Northern Italy
Central Europe UK
Scandinavia
Di Guardo et al. (2017) Sci Total Environ 580,

12. Results: bioavailable concentrations
PCB52
1.6E-02
1.2E-02
Conc. (ng L-1)
8.0E-03
4.0E-03
log KOW
PCB52
6.1
PCB153
6.9
PCB208
8.16
0.0E+00
PCB153
1.6E-02
1.2E-02
Conc. (ng L-1)
8.0E-03
4.0E-03
0.0E+00
PCB208
5.0E-03
4.0E-03
3.0E-03
Conc. (ng L-1)
2.0E-03
1.0E-03
0.0E+00 J F M A M J J A S O N D
Mediterranean
Northern Italy
Central Europe UK
Di Guardo et al. (2017) Sci Total Environ 580,
Scandinavia

13. Results: exposure variability vs. log KOW
Di Guardo et al. (2017) Sci Total Environ 580,

14. Results: depleting capacity of scenarios
% depletion
Predicted depletion (%) with respect to maximum concentrations as a function of log KOW and POC concentration (mg/L) for two scenarios
Di Guardo et al. (2017) Sci Total Environ 580,

15. Conclusions (1) Phytoplankton European scenarios Exposure variations
Graphical abstract of the paper... Speaks by itself
Di Guardo et al. (2017) Sci Total Environ 580,

16. Conclusions (2)
ChimERA fate: useful tool for predicting exposure dynamics in shallow water environments (now includes primary producers and carbon dynamics)
Dynamic realistic scenarios for meso-eutrophic shallow water bodies developed → investigation of potential exposure variations at different latitudes
Future work
Sensitivity and uncertainty analyses
Calibration and validation (literature + experiments)
Scenario improvement, e.g., considering allochthonous carbon
Related work
Coupling between ChimERA fate and effect models (TK/TD-IBM sub- models)

17. Thanks for your attention
Acknowledgements
The ChimERA project was financed by the Long-range Initiative of CEFIC ( (project code: LRI-ECO19)
Thanks for your attention