Science Inventory



Breckenridge, C., D. Sargent, J. Evans, K. R. Solomon, V Zartarian, D. Vogel, W. D. Shade, J. Driver, M. Pandian, A. J. Goetz, S. Pettit, G. J. Mihlan, D. Miller, AND J. Zabik. HESI EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT. Presented at Society for Risk Analysis Conference 2003, Baltimore, MD, December 7-10, 2003.


The primary objective of this research is to produce a documented version of the aggregate SHEDS-Pesticides model for conducting reliable probabilistic population assessments of human exposure and dose to environmental pollutants. SHEDS is being developed to help answer the following questions:

(1) What is the population distribution of exposure for a given cohort for existing scenarios or for proposed exposure reduction scenarios?

(2) What is the intensity, duration, frequency, and timing of exposures from different routes?

(3) What are the most critical media, routes, pathways, and factors contributing to exposures?

(4) What is the uncertainty associated with predictions of exposure for a population?

(5) How do modeled estimates compare to real-world data?

(6) What additional human exposure measurements are needed to reduce uncertainty in population estimates?


In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of input variables in the overall estimation of total exposure and risk to an individual person with demographic, geographic and temporal specificity. However, a risk assessor's ability to evaluate the validity of a model outcome is predicated on a clear understanding of the quality and variability associated with these input variables. As such, the ILSI Health and Environmental Sciences Institute's (HESI) Risk Assessment Methodologies Technical Committee (RAM Committee) identified the need for better characterization and electronic availability of public, non-chemical specific data sets for use in state-of-the-science aggregate residential exposure models. As a first step, the RAM Committee, in conjunction with, Inc., has reviewed public data on micro- and macro-activity activity factors (e.g., mouthing behavior event frequencies, time spent on a residential lawn), and mass-transfer-related factors (e.g., surface-to-skin/clothing mass transfer, biological monitoring measurements following choreographed dermal exposure events, dermal transfer coefficients, and transfer removal efficiencies). These data were evaluated both qualitatively and quantitatively and organized in an electronic database with their associated meta information. Additional data, meta information, and guidance can be added to this database in the future. Further, this effort provides important opportunities for collaboration and synergy with the EPA's Exposure Factors Handbook (general and child-specific) and regulatory agency exposure assessment methods development (e.g., EPA, Office of Pesticide Programs, Standard Operating Procedures for Residential Exposure Assessment). This database will be made publicly available and will assist risk assessors responsible for deterministic and probabilistic aggregate/cumulative residential risk analyses. The HESI RAM Technical Committee is composed of scientists from academia, industry, and government.

This work has been funded in part by the United States Protection Agency. It has been subjected to Agency review and approved for publication.

Record Details:

Product Published Date: 12/09/2003
Record Last Revised: 06/21/2006
Record ID: 63081