Land contamination can affect the health of people living, working, visiting or otherwise present on a site. The risk assessment process is used to establish whether there is an unacceptable risk to humans.

Contaminated Land Exposure Assessment (CLEA)

• Human health toxicological assessment of contaminants in soil (Science Report Final SC050021/SR2) (PDF, 718KB)
  This report describes the technical principles and framework the EA use to derive Health Criteria Values.
• Updated technical background to the CLEA model (Science Report Final SC050021/SR3) (PDF, 1.60MB)
  This report describes the technical background to the CLEA model. It also sets out the underlying assumptions that the EA have made to predict exposure for three standard land use scenarios (residential, allotments and commercial).
• Environment Agency Science Reports relevant to CLEA

CLEA Software and Handbook

• CLEA software v 1.071
• CLEA software v 1.06
• CLEA Licence Agreement
• CLEA handbook v 1.05

  The CLEA software version 1.05 handbook is still relevant to version 1.06 and 1.071 and has not been changed.

Toxicological Reports (TOX) (INFO-RA2-2d)

• TOX Reports for SGV derivation

Soil Guideline Values (SGVs) (INFO-RA2-2e)

• Soil Guideline Values
• Published SGVs

Category 4 Screening Levels (C4SL)

• Category 4Screening Levels (C4SLs)

Generic Screening Values (GAC)

• EIC/AGS/CL:AIRE Generic Assessment Criteria (GAC)
• LQM/CIEH S4UL 
• SoBRA: Development of Generic Assessment Criteria for Assessing Vapour Risks to Human Health from Volatile Contaminants in Groundwater

Bioaccessibility

• Measurement of Bioaccessibility of Arsenic in UK Soils, P5-062/TR02, EA, 2002.(PDF, 72KB) (INFO-RA2-2f)
• International workshop on the potential use of bioaccessibility testing in risk assessment of land contamination, Science Report SC040054, 2005
• In-vitro Bioaccessisbility Testing: Current Science and Way Forward. Environment Agency Science Update 2, 2007
• Environment Agency views on using in vitro bioaccessibility data in land contamination risk assessments for human health, June 2007
• Additional bioaccessibility references are available from Science Reports relevant to CLEA

General Information 

• Method for Deriving Site-specific Human Health Assessment Criteria for Contaminants in Soils, LQ01, SNIFFER, SEPA, EA, 2003. (INFO-RA2-2g)
• Human Health Risk Assessment – Detailed Quantitative Risk Assessment, EA (No report produced). (INFO-RA2-2h)
• The UK Approach for Evaluating the Human Health Risks from Petroleum Hydrocarbons in Soils EA, 2005 (PDF, 536KB)

 TPH Working Group Series (TPHCWG)

• Petroleum Hydrocarbon Analysis of Soil and Water in the Environment, Volume 1, TPHCWG, 1998. (INFO-RA2-2i)
• Composition of Petroleum Mixtures, Volume 2, TPHCWG, 1998. (INFO-RA2-2j)
• Selection of Representative TPH Fractions Based on Fate and Transport Considerations, Volume 3, TPHCWG, 1997. (INFO-RA2-2k)
• Development of Fraction-specific Reference Doses (RfDs) and Reference Concentrations (RfCs) for TPHs, Volume 4, TPHCWG, 1997. (INFO-RA2-2l)
• Human Health Risk-based Evaluation of Petroleum Release Sites: Implementing the Working Group’s Approach, Volume 5, TPHCWG, 1999. (INFO-RA2-2m)

Contaminated Land Reports (CLR) - All withdrawn

• CLR7 Overview of the Development of Guideline Values and Related Research, DEFRA/EA, 2002. (INFO-RA2-2a) Withdrawn.
• CLR8 Priority Contaminants Report, DEFRA/EA, 2020.Withdrawn.
• CLR9 Contaminants in Soils: Collation of Toxicological Data and Intake Values for Humans. Consolidated Main Report, CLR 9 DEFRA/EA, 2002. (INFO-RA2-2b). The Environment Agency completely re-wrote the old CLR9 report (now called the Human health toxicological assessment of contaminants in soil (Science Report Final SC050021/SR2)) to take account of Defra's ‘Way Forward’ exercise on Soil Guideline Values and other changes to the underlying science.
• CLR 10 The Contaminated Land Exposure Assessment Model (CLEA): Technical Basis and Algorithms. DEFRA/EA, 2002. (INFO-RA2-2c). This has been withdrawn and rewritten as CLEA.