Site Mitigation & Restoration Program

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Human and Ecological Risk Office


A tool for evaluating exposure and the potential for adverse health effects resulting from exposure to lead in the environment

LeadSpread was created to run on Microsoft Excel®

LeadSpread 7 is the DTSC Lead Risk Assessment Spreadsheet. LeadSpread 7 was last updated in January 2009.

Please note that an updated version of LeadSpread has been developed (LeadSpread 8; 2011) to incorporate the updated CalEPA incremental lead toxicity criterion of 1 ug/dL (OEHHA, 2007) as well as ensure that the model is adequately protective of women of child-bearing age. LeadSpread 7 is maintained on this web page for sites outside California being evaluated based on the 10 ug/dL total blood lead criterion. For California sites, LeadSpread 8 and the LeadSpread 8 “User’s Guide and Recommendations for Evaluation of Lead Exposures in Adults” document should be consulted.      Go to the LeadSpread-8 Page

Background: LeadSpread is a tool that can be used to estimate blood lead concentrations resulting from exposure to lead via dietary intake, drinking water, soil and dust ingestion, inhalation, and dermal contact. Each of these pathways is represented by an equation relating incremental blood lead increase to a concentration in an environmental medium, using contact rates and empirically determined ratios. The contributions via the five pathways are added to arrive at an estimate of median blood lead concentration resulting from the multi-pathway exposure. Ninetieth, ninety-fifth, ninety-eighth, and ninety-ninth percentile concentrations are estimated from the median by assuming a log-normal distribution with a geometric standard deviation (GSD) of 1.6.

Documentation on LeadSpread is contained as notes within the spreadsheet.

Improvements incorporated in version 7 are described in two posters presented on 20 March 2000 at the Annual Meeting of the Society of Toxicology in Philadelphia. These posters require Adobe Acrobat Reader to view and can be downloaded by clicking on the following links:

Updated Version of the California EPA Lead Risk Assessment Spreadsheet Model for Predicting Blood lead in Children and Adults
James Carlisle, John Christopher, Brian Davis, Kimiko Klein, Barbara Renzi, and Michael Wade. Society of Toxicology – March, 2000

Comparison of Updated LeadSpread to Integrated Exposure, Uptake, and Biokinetic Model (IEUBK) for Predicting Blood Lead in Children
John Christopher, James Carlisle, Brian Davis, Kimiko Klein, Barbara Renzi, and Michael Wade.  Society of Toxicology – March, 2000

NOTE: If you have comments on LeadSpread 7, please include them in an e-mail message to Kimberly Gettmann at

Page updated April 9, 2019