1. Derivation of ecotoxicological quality standards for PAHs
on the basis of internal lipid concentrations
16 September 2010

2. History of EQSs derivation for PAHs
1995: DF Kalf, GH Crommentuijn, R Posthumus, EJ van de Plassche RIVM report
10 PAHs
Water, soil and sediment
(Very) limited amount of data
2005: European Union, Fact sheets priority substances Water Framework Directive
Naphtalene, Anthracene, Fluoranthene and 5 PAHs (5-6 rings)
Water and sediment
More data, in part based on early version of EU RAR
2008: European Union, (draft) final Risk Assessment Report
16 PAHs
Lot of data
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

3. This study
Performed for both generic quality standards and soil clean-up framework
Based on but not limited to EU RAR
Soil clean up framework requires more protection levels
E.g. HC20, HC50, median values
This requires thorough evaluation of all data
More than 270 references
All thoroughly evaluated
Klimisch code assigned
Analytical verification
Solubility issues
Realistic (representative) conditions
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

4. Valid acute aquatic toxicity data
Huge range of EC50s
Strong correlation with hydrophobicity
Phototoxicity apparent for anthracene, pyrene, and fluoranthene (no valid data chrysene)
100000
LC50 or EC50 [µg/L]
0.01 3 4 5 6 7
log K ow
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

5. Valid chronic aquatic toxicity data
Huge range of NOECs and EC10s
Strong correlation with hydrophobicity
Phototoxicity has little influence
100000
NOEC or EC10 [µg/L]
0.01 3 4 5 6 7
log K ow
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

6. Valid chronic terrestrial toxicity data
Much smaller range of NOECs and EC10s
No correlation with hydrophobicity
100000
NOEC or EC10 [µg/kg dw] 3 4 5 6 7
log K ow
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

7. Valid chronic benthic toxicity data
Similar to soil
Few data (five PAHs) 3 4 5 6 7
log K ow
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

8. Interim conclusions Many data Toxicity hydrophobicity dependent
Assumptions
Similar mode of toxic action
Joint action
Accumulation driven by hydrophobicity
Derive EQSs for PAHs similar to TPH (Verbruggen et al 2008)
Recalculate all toxicity data to internal residues
Organic carbon – water partition coefficients for soil and sediment
Membrane lipids – water partition coefficients for all compartments
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

9. SSD for PAHs based on internal residues
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

10. Conclusions
Toxicity of PAHs can be modelled by membrane - water partitioning
From scientific point of view: Measure free dissolved concentrations to reduce uncertainties in bioavailability
Toxicity of PAHs is very comparable to TPH
Mode of toxic action probably is narcosis
Nevertheless, QS from experimental data << QSAR based QS
Joint toxicity
Same mode of action, apply concentration addition
Toxic Unit approach
Secondary poisoning, human fish consumption not included yet
Issue with bioconcentration factor (fish versus mussels)
Carcinogenicity
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010

11. Comparison with WFD fact sheets
Substance
EQS this study HC5 with AF 5
WFD fact sheets
Naphthalene
6.0
2.4
Acenaphthylene
4.5
Acenaphthene
2.0
Fluorene
1.2
Phenanthrene
0.66
Anthracene
0.45
0.11
Pyrene
0.28
Fluoranthene
0.17
0.1
Chrysene
0.062
Benz[a]anthracene
0.054
Benzo[k]fluoranthene
0.046
0.03
Benzo[b]fluoranthene
0.045
Benzo[a]pyrene
0.05
Benzo[ghi]perylene
0.044
0.002
Dibenzo[a,h]anthracene
0.031
Indeno[1,2,3-cd]pyrene
0.029
Derivation of ecotoxicological quality standards for PAHs | 16 September 2010