Final Report: Guidance for Assessing Exposures and Health Risks at Existing and Proposed School Sites

The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency is making available the final document, "Guidance for Assessing Exposures and Health Risks at Existing and Proposed School Sites Pursuant to Health and Safety Code 901(f)."   This document was prepared to comply with California Health and Safety Code Section 901(f), which requires OEHHA to develop and publish a guidance document for use by the Department of Toxic Substances Control and other state and local environmental and public health agencies to assess exposures and health risks at existing and proposed school sites, including child-specific routes of exposure unique to the school environment, in addition to those in existing exposure models.  (This notice is also available in pdf format.)

OEHHA has followed the requirements set forth in Health and Safety Code Section 57003 for receiving public input.

  • The first draft document was released for public review on December 20, 2002.  
  • A public workshop was held in January 2003 to discuss the scientific basis and recommendations in the draft report.  
  • After considering public comments, OEHHA revised the document and released a final draft for additional public review in November 2003.  
  • The release of this final document is a culmination of this public input process.  The document includes all comments received and responses to those comments.

The algorithms and equations in the Guidelines have been incorporated into an Excel spreadsheet ("Schoolscreen") containing toxicological data for approximately 370 chemicals and physical chemical data for approximately 90 chemicals. Soil vapor and human milk exposure pathways cannot be evaluated for chemicals with incomplete databases. The user is responsible for data added to the spreadsheet. The authors believe the algorithms to be an accurate reflection of the Guidelines.

The Workbook and all sheets are protected to avoid inadvertent changes. No password is required to unprotect the sheets or the workbook. This spreadsheet is a work in progress. As significant data are added or changes made, new versions will be released.

Spreadsheet Updated [01/13/10]

Update corrected a unit error in column D, rows 8-14, in all of the age-specific worksheets except 1-2. micrograms per liter was changed to milligrams per liter. This is only a label change - the results are not affected.

In the original "Schoolscreen" spreadsheet, the annual average daily dose and the reference dose were not in the same units, resulting in error in calculating the hazard quotients. Also, the dermal absorption coefficient was not incorporated into the dermal dose calculation. This error affected both hazard quotients and cancer risk, although the affect would not affect the answer expressed to 2 significant digits. We regret any inconvenience this error may have caused. 

Spreadsheet Removed [11/01/13]

If you have questions, please contact Carmen Milanes by email at carmen.milanes@oehha.ca.gov, by phone at (916) 323-4153, or at the address below.  Written requests or comments should be addressed to:

Carmen Milanes
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-12B
1001 I Street
Sacramento, California 95812-4010
FAX: (916) 322-9705