Subtitel

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