nbv marlea wagelmans
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Marlea Wagelmans, Wageningen, 1 December 2011.
Risk assessment at work and challanges for the future
Contents
• Risk Assessment in the Netherlands
• Examples
• Bottlenecks
• Conclusions
Risk assessment in the Netherlands
Step 2: Model (Sanscrit): total concentrations
Step 3: Site specific risk assessment (ecology=Triad)
Step 1: Soil research
> Intervention values
Volume > I
Example: River Bank
• Tidal river, banks uncovered during low tide
• Important natural values, reed vegetation
• Contaminated sediment, PAH, mineral oil, metals
• Traditional dredging loss of natural values
Activities
• Chemical analyses
• Bioavailability PAH
• Biodegradation tests PAH and mineral oil (aerobic) and PCB (anaerobic)
• Triad (top)
3 rows, 3 sampling points per row (wet, tidal and dry zone), 3 depths per point Dry Tidal Wet
R3A
R2A
R1A
R3C
R2C
R1C
R3E
R1E
R2E
Details Triad
activities Tidal zone Reed zone
Chemistry
Chemical analyses sediment
Chemical analyses soil
Bioaccumulation tubifex
Toxicology
Microtox Microtox
Daphnia magna test Plant test
Chironomus riparius test Earthworm test
Ecology Nematodes Nematodes
Macrofauna Earthworm population
Results PAH availability
Results biodegradation tests
Anaerobic test Aerobic tests
Results Triad approach
activities Tidal zone Reed zone
Chemistry High concentrations metals, PAH and PCB
Moderate concentrations metals, PAH and PCB
Risks on bioaccumulation of lead, cadmium and chromium
Toxicology Negative effects bacteria No effects bacteria
No effects Daphnia magna No effects plant test
No effects Chironomus riparius test
No effects earthworm test
Ecology Negative effects nematodes Moderate effects nematodes
Negative effects macrofauna No effect on earthworms
Summary Negative effects, not acceptable
Moderate effects, acceptable
Summarizing
dry tidal wet
Remediation options
Wet and tidal zone
Remediation (dredging or enhanced bioremediation
Dry zone
Natural attenuation
Example 2: Former military airport
• PAH (volume > 2.000 m3)
• Nature area, within EHS
• Origin: possibly tar and rubber, maybe also debris
• Ecological risk (Sanscrit)
Triad
Results chemistrychemistry
toxicology ecology
parameter unit 7 8 10 13 14 16
PAH mg/kg dw 34 990 92 170 7 59
PAF total % 60 100 96 100 59 82
PAFavailable % 0 0 0 0 0 0
> Intervention value
PAF = Potentially Affected Fraction
Toxicology and ecology
• No negative effects Microtox
chemistry
toxicology ecology
Nitrification Nematodes
Summary
R= Triad risk valueD= deviation
RIVM rapport 607711003/2011
R < 0,25R > 0,25D > 0,40
BC14 BC7 BC16 BC10 BC13 BC8
Chemistry
Toxic pressure
0,06 0,34 0,48 0,57 0,71 0,95
Availability 0,0 0,0 0,0 0,0 0,0 0,0
Judgement 0,03 0,18 0,28 0,34 0,46 0,77
Risk assessment
Chemistry 0,03 0,18 0,28 0,34 0,46 0,77
Toxicology 0,0 0,0 0,0 0,0 0,0 0,0
Ecology 0,0 0,01 0,07 0,0 0,07 0,0
R 0,01 0,07 0,10 0,13 0,19 0,39
D 0,03 0,18 0,28 0,34 0,40 0,76
Summary
• High concentrations PAH
• PAH not available
• No effects toxicology
• No effects ecology
• No urgent remediation needed
Challange for the future
• detailed information about effects on functioning or system level
• detailed information about the cause of effects• efficient in acute and chronic pollution situation• micropollutants: new endpoints?
Molecular tools
Conclusions
• Effective in ecological risk assessment
• Identify management options
• Still some bottlenecks: biotechnology?
Thanks for your attention
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