Plugging the SGV void – the new LQM/CIEH GAC

1. Plugging the SGV void – the new LQM/CIEH GAC Caroline McCaffrey Land Quality Management Ltd Brownfield Briefing Contaminated land Risk Assessment London, 23rd September 2009

2. Consultancy – investigation, assessment & management of land contamination Desk studies & conceptual site models Site investigation & characterisation Risk estimation & evaluation Risk management Options appraisal Expert Witness Peer Review Services Research site characterisation risk assessment remediation decision support brownfield regeneration Training Short Courses Bespoke courses MRes Contaminated Land Management LQM Activities

3. Generic Assessment Criteria for use in human health risk assessment Result of collaborative working LQM & Chartered Institute of Environmental Health (CIEH) 82 workshop participants What are the LQM/CIEH GAC?

4. 2nd edition LQM/CIEH GAC • Replaces 1st edition published in November 2006 • Revision due to changes in the technical guidance for human health risk assessment • Publication of SR2, SR3, SR4 & CLEA v1.04 software

5. Pre-Workshop • 82 Practitioners – regulators, consultants and land owners • 77 substances • Pre-workshop – each delegate assigned up to 3 substances • Derive toxicological benchmarks & physical-chemical data • Each substance researched by at least 3 delegates

6. During the workshop Substance specific pre-workshop reports available to delegates For each substance – delegates were working in groups of 3 or 4 Discussed and agreed data inputs – informed by pre-workshop reports

7. Using CLEA v1.04 • All group members derived GAC using CLEA v1.04 • All generic land uses

8. After the Workshop LQM review of workshop outputs Data inputs Consistency Revision of input parameters, where required Check of compliance with latest guidance Check of GAC calculations Prepare for publication

9. LQM/CIEH GAC Are intervention levels for use in Generic Quantitative Risk Assessment (GQRA) Adopt a cautious approach e.g. for some substances if no background data assumed in deriving the toxicological inputs for a threshold effect assumed that background exposure is 50% of Tolerable Daily Intake

10. SSAC ‘new’ LQM/CIEH GAC ‘new’ SGVs? ‘old’ LQM/CIEH GAC ‘old’ SGVs

11. LQM/CIEH GAC are • Robust • Defensible • Transparent • All inputs provided to allow the user to make their own evaluation • Scientifically derived • Used CLEA v1.04 • Inputs derived from Environment Agency documents, where available • Intervention values

12. Metals Beryllium boron Cadmium Chromium (III & VI) Copper Vanadium zinc Petroleum Hydrocarbons 16 fractions Polyaromatic Hydrocarbons USEPA 16 GAC published for …

13. Chloroalkanes & alkenes 1,2-Dichloroethane 1,1,1-Trichloroethane 1,1,2,2- and 1,1,1,2- Tetrachloroethanes Tetrachloromethane Trichloroethene Trichloromethane Chloroethene Explosives 2,4,6-Trinitrotoluene RDX & HMX Pesticides Aldrin & Dieldrin Atrazine Dichlorovos Endosulfans Hexachlorocyclohexanes GAC published for …

14. Chlorobenzenes Chlorobenzene Dichlorobenzenes (3) Trichlorobenzenes (3) Tetrachlorobenzenes (3) Pentachlorobenzenes Hexachlorobenzene Phenol & Chlorophenols Phenol Chlorophenols (4) Pentachlorophenol Other Carbon disulphide Hexachlorobutadiene GAC published for …

15. Underpinning conceptual site model • SR3 landuses • Residential with homegrown produce • Allotments • Commercial/industrial • 1%, 2.5% and 6% Soil Organic Matter • Sandy Loam soil

16. Cadmium • SGV published on 21st July 2009 Residential with homegrown produce 6% SOM, Sandy loam soil

17. Why the difference? • Different inhalation TOX data • SGV – lifetime exposure • SGV – systemic effects • LQM/CIEH GAC – considers localised lung effects

18. Phenol • SGV published on 21st July 2009 Residential with homegrown produce 6% SOM, Sandy loam soil *exceeds saturation limits; # based on a threshold protective of direct skin contact

19. Why the difference? • Same oral TOX, different MDI • SGV lower inhalation TOX – based on limited occupational epidemiology data • Higher dermal absorption factor • SGV – systemic effects - dermal exposure compared with inhalation TOX data

20. Collaboration • Collaborative workshops of regulators and practitioners may be a way to … – accelerate the production of screening levels – establish common ground (rather than harmonisation sensu stricto) – reduce inconsistency – share knowledge and expertise – develop confidence and mutual respect among risk assessors and regulators

21. Why use the LQM/CIEH GAC? • Cost effectiveness • Simplify decision making • Easy to understand & interpret • Provide a common platform • Consistency • Transparent

22. How do I use the LQM/CIEH GAC? • Read the accompanying chapter • Detailed explanation of toxicological and physical-chemical data inputs • If appropriate for use at your site – use as ‘intervention values’

23. Using the LQM/CIEH GAC • Be clear on the purpose of the GAC • Go back to basics – are the GAC suitable for use at this particular site? • Check conceptual site model carefully • Be aware of the assumptions • GAC are not SPOSH or clean-up levels

24. Remember • All risk assessments are site specific even when using GAC • Look at lines of evidence • Interrogate data (e.g. laboratory results & borehole logs) • Not all GAC are derived using the same assumptions as LQM/CIEH GAC • Guidance is open to interpretation

25. Making decisions • Robust • Transparent • Scientifically valid • Consistent • Reasonable • Appropriate to the legislative framework • You may be challenged

26. Frequently Asked Questions • Is the document available electronically? • Is there a spreadsheet of the data inputs? • Why do I get a slightly different GAC to that presented? • Available at www.lqm.co.uk

27. Dissemination to date • Over 400 copies have been issued • 60:40 Consultancy/Local Authority spilt

28. Order your copy • Order form available at www.lqm.co.uk • £195 including p&p • Fax back on 0115 9678798 • Email to administrator@lqm.co.uk

29. Contact Details Caroline McCaffrey Tel: 0115 9518030 Fax: 0115 9678798 E: caroline.mccaffrey@lqm.co.uk