Current issues in contaminated land risk assessment 2012
Meeting report by Kate Jones
Health and Safety Laboratory
ECG Bulletin July 2012
Health and Safety Laboratory
ECG Bulletin July 2012
A report of the Joint Meeting of the Society of Brownfield Risk Assessment (SoBRA)/RSC Toxicology Group held at the RSC’s Chemistry Centre, Burlington House, London on December 21st 2011.
I am happy to report another successful meeting, jointly hosted by SoBRA and the RSC Toxicology group. The December meeting has become established as a forum for updating delegates and exchanging views on the current issues within contaminated land risk assessment.
The day opened with the out-going Chair of SoBRA, Mary Harris, welcoming delegates to the meeting. Dr Chris Johnson (British Geological Survey) was the first speaker, outlining a project to map the background levels of soil contamination across England. This will allow interpretation of what soil contamination is considered ‘above background’, and may thus need further investigation. Of course, there is no universal ‘background’ across the country as industrial activity (past and present) and geological factors can result in local hotspots.
Mike Quint (Environmental Health Sciences Ltd) then gave a presentation on the thorny issue of defining ‘significant possibility of significant harm’. The new proposals in the consultation draft discussed by Mike have introduced categories of contaminated land. Models have been developed to help determine categories, such as LQM/CIEH dose response roadmaps and the ATSDR approach. The models are in development and caution needs to be taken, as was memorably stated by Mike ‒ all ‘blobs’ (data points) aren’t equal!
After refreshments, there were two presentations from the nuclear sector. Candida Lean gave an overview of the ReCLAIM dose assessment tool, which calculates radiation exposure doses from multiple pathways for >50 radionuclides and accounts for different depths of contamination. It can be used to generate radiation exposure scenarios with user-specified inputs to customise the model. The tool is Excel-based and free to download. The second presentation was a group effort describing the nuclear industry guidance on qualitative risk assessment. The guidance is based on existing guidelines and was developed through industry workshops and peer-review. The tool is mainly for assessing risks from land in its current state. The guidance was issued in December 2011 and is open for comment until November 2012; a revision is planned for 2013.
Next, Sue Goodman from the Environment Agency outlined the role of the Water Framework Directive, which requires all waters to achieve ‘good status’ by 2015. In the North East region, a significant number of watercourses are currently graded below ‘good’. The reasons for this are diverse but some are thought to be due to contaminated land and the Environment Agency is looking to implement an evidence-based project to identify such sites. Tristan Ibrahim then spoke about the interactions between groundwater and surface water that need to be considered in order to understand pollution movement, particularly the concept of Hyporheic Exchange Flow.
Dave Megson (University of Plymouth) and Sarah Dack (Mouchel) then reported a case study on dioxin/furan contamination at an allotment site. Using the CLEA model there was no SPOSH (Significant Possibility of Significant Harm) from the dioxin/furan contamination but many of the allotments were used to keep chickens/ducks. All eggs tested exceeded the EU guideline of 3 ng/kg fat. An example of a child living next to the site and eating eggs from the site was estimated to exceed the TDI for dioxins/furans by up to 9 times. As a result the site was deemed contaminated and remediation will be undertaken.
Finally, Tracy Braithwaite (AWE) outlined the Soil and Groundwater Technology Association’s (SAGTA) proposed actions in light of the new developments on risk assessment, particularly understanding sustainable risk assessments, the absence of supporting guidance for the national planning policy framework, the definition of land use categories and groundwater risk assessment compliance points. Anyone interested in contributing to SAGTA’s responses should get in touch. The meeting closed with a lively discussion of unresolved issues and a drinks reception that enabled the discussion to continue a little longer. Many issues remain, however, and some, at least, will be addressed at this year’s meeting (December 2012) - be sure to book your place!
KATE JONES
Principal Scientist, Health & Safety Laboratory, UK
Most presentations from this meeting are available at http://www.rsc.org/Membership/Networking/InterestGroups/Toxicology/Meetings.as. This report is reproduced in abridged form with permission from the Toxicology Group Newsletter – Spring/Summer 2012.
I am happy to report another successful meeting, jointly hosted by SoBRA and the RSC Toxicology group. The December meeting has become established as a forum for updating delegates and exchanging views on the current issues within contaminated land risk assessment.
The day opened with the out-going Chair of SoBRA, Mary Harris, welcoming delegates to the meeting. Dr Chris Johnson (British Geological Survey) was the first speaker, outlining a project to map the background levels of soil contamination across England. This will allow interpretation of what soil contamination is considered ‘above background’, and may thus need further investigation. Of course, there is no universal ‘background’ across the country as industrial activity (past and present) and geological factors can result in local hotspots.
Mike Quint (Environmental Health Sciences Ltd) then gave a presentation on the thorny issue of defining ‘significant possibility of significant harm’. The new proposals in the consultation draft discussed by Mike have introduced categories of contaminated land. Models have been developed to help determine categories, such as LQM/CIEH dose response roadmaps and the ATSDR approach. The models are in development and caution needs to be taken, as was memorably stated by Mike ‒ all ‘blobs’ (data points) aren’t equal!
After refreshments, there were two presentations from the nuclear sector. Candida Lean gave an overview of the ReCLAIM dose assessment tool, which calculates radiation exposure doses from multiple pathways for >50 radionuclides and accounts for different depths of contamination. It can be used to generate radiation exposure scenarios with user-specified inputs to customise the model. The tool is Excel-based and free to download. The second presentation was a group effort describing the nuclear industry guidance on qualitative risk assessment. The guidance is based on existing guidelines and was developed through industry workshops and peer-review. The tool is mainly for assessing risks from land in its current state. The guidance was issued in December 2011 and is open for comment until November 2012; a revision is planned for 2013.
Next, Sue Goodman from the Environment Agency outlined the role of the Water Framework Directive, which requires all waters to achieve ‘good status’ by 2015. In the North East region, a significant number of watercourses are currently graded below ‘good’. The reasons for this are diverse but some are thought to be due to contaminated land and the Environment Agency is looking to implement an evidence-based project to identify such sites. Tristan Ibrahim then spoke about the interactions between groundwater and surface water that need to be considered in order to understand pollution movement, particularly the concept of Hyporheic Exchange Flow.
Dave Megson (University of Plymouth) and Sarah Dack (Mouchel) then reported a case study on dioxin/furan contamination at an allotment site. Using the CLEA model there was no SPOSH (Significant Possibility of Significant Harm) from the dioxin/furan contamination but many of the allotments were used to keep chickens/ducks. All eggs tested exceeded the EU guideline of 3 ng/kg fat. An example of a child living next to the site and eating eggs from the site was estimated to exceed the TDI for dioxins/furans by up to 9 times. As a result the site was deemed contaminated and remediation will be undertaken.
Finally, Tracy Braithwaite (AWE) outlined the Soil and Groundwater Technology Association’s (SAGTA) proposed actions in light of the new developments on risk assessment, particularly understanding sustainable risk assessments, the absence of supporting guidance for the national planning policy framework, the definition of land use categories and groundwater risk assessment compliance points. Anyone interested in contributing to SAGTA’s responses should get in touch. The meeting closed with a lively discussion of unresolved issues and a drinks reception that enabled the discussion to continue a little longer. Many issues remain, however, and some, at least, will be addressed at this year’s meeting (December 2012) - be sure to book your place!
KATE JONES
Principal Scientist, Health & Safety Laboratory, UK
Most presentations from this meeting are available at http://www.rsc.org/Membership/Networking/InterestGroups/Toxicology/Meetings.as. This report is reproduced in abridged form with permission from the Toxicology Group Newsletter – Spring/Summer 2012.
