# Presentation: 817237

## Databases and Tools for Use in Conducting Aggregate and Cumulative Assessments 

**Databases and Tools for Use in Conducting Aggregate and Cumulative Assessments **
- Jacqueline Moya1, Carry Croghan2, Tom McCurdy2, Amina Wilkins1
- 1U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Washington DC
-  2U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, RTP, North Carolina

- What are the available exposure tools and scientific information for assessing aggregate and cumulative exposures in support of Agency’s regulations and decision- making?
- How can the Office of Research and Development (ORD) develop, organize, integrate, synthesize, and communicate important exposure information and tools to support scientifically sound integrated solutions to complex environmental problems?

**Research Goals**

**Methods/Approach**

**Impact and Outcomes**

**Results/Conclusions**

**Future Directions**

**Science Question**

- Risk Assessments are important components of the decision making process. One of ORD’s missions is to strengthen the scientific foundation of EPA’s risk assessments and risk management decisions.  In recent years, risk assessment has evolved from evaluating a single stressor in one environmental medium to evaluating aggregate and cumulative exposures. Therefore, it is critical that the up-to-date methods, models, and exposure data are available to the exposure and risk assessor to realistically estimate the potential for human and ecological exposures to environmental contaminants.  Scientific tools are needed to refine aggregate and cumulative assessments.  The Office of Research and Development has several efforts to provide human exposure data necessary for assessing exposure to multiple contaminants in the environment.

- ORD efforts to provide the most up-to-date data on exposures strengthen the scientific foundation of the EPA risk assessments and risk management decisions.

- The use of the scientific information improves Agency efforts in identifying, assessing, and mitigating risks to those populations who may be exposed to environmental chemicals from various sources.  This information also assists the Agency in identifying data gaps so that future research efforts can be targeted to fulfill those data needs.  Providing the most up-to-date data on environmental exposure and improving their access to Agency users, states, stakeholders, and the public is critical for scientists involved in conducting exposure assessments.  Integrating data and providing universal access to it via the Web is consistent with EPA’s Information Management goal of improving access to environmental data.

- Future updates of the Exposure Factors Handbook and the Child-Specific Exposure Factors Handbook will incorporate data contained in HEDS, CHAD, and the NHEXAS analysis.  Additional analysis of the data contained in CHAD is underway and will expand our knowledge of inhalation rates as a function of activities.  HEDS will be updated as more data become available.

**References**

- McCurdy T., Graham G., Smith L., Lakkadi Y.  The National Exposure Research Laboratory’s consolidated human activity database.  Journal of Exposure Analysis and Environmental Epidemiology. 10, 566-578.
- Robertson, G.L., Quackenboss, J.J., Hern, S.C., and Thompson, C.B.  The human exposure database system (HEDS)-putting the NHEXAS data on-line. Presented at: 11th Annual Meeting of the International Society of Exposure Analysis, Charleston, SC, November 4-8, 2001.U.S.
- U.S. EPA 1997. Exposure Factors Handbook. National Center for Environmental Assessment, Office of Research and Development, EPA/600/P-95/002Fa-c
- U.S. EPA 2002.  Child-Specific Exposure Factors Handbook. Interim Final.  National Center for Environmental Assessment, Office of Research and Development.  EPA/600/P-00/002B.

-   An integrated database system that contains chemical measurements, questionnaire responses, documents, and other information related to EPA research studies of the exposure of people to environmental contaminants.
-   A web-enabled data repository for human exposure studies.  Its mission is to provide data sets, documents, and metadata for human exposure studies that can be easily accessed and understood by a diverse set of users.
-   HEDS operates in conjunction with the Environmental Information Management System (EIMS), ORD's metadata repository.
-   HEDS provides only data and accompanying documentation from research studies; it does not provide interpretations.
-   It allows a user to download documents for review or data sets for analysis on their own computer system. For more information about HEDS, visit www.epa.gov/heds

-   The *Exposure Factors Program* is a comprehensive program with the primary goal of compiling, analyzing, and summarizing exposure factors data to be used in future updates of the *Exposure Factors Handbook* and the *Child-Specific Exposure Factors Handbook*.
-   The EPA *Exposure Factors Handbook* and the *Child-Specific Exposure Factors Handbook* are tools available to exposure assessors, which summarize statistical data on exposure factors necessary to conduct human health exposure assessments (e.g.,  water consumption, soil ingestion, inhalation rates, etc.)
-   The use of the Handbook has resulted in more consistency among exposure assessments conducted by the Agency and outside.
- An Agency-wide advisory group has been established to assist ORD in identifying data gaps and set priorities for exposure factor’s research.
-   For more information on the Exposure Factors Program, visit www.epa.gov/ncea

-   The *Consolidated Human Activity Database* (CHAD) is a database of almost 23,000 person-days of 24 h human activity information on an activity-by-activity basis.
-   Demographic information for each subject providing data are included in questionnaire format.  The data were obtained from pre-existing human activity studies that were collected at city, state, and national levels over a twenty-year period.
-   CHAD is intended to provide input data in a consistent format for exposure/intake dose modeling and/or statistical analysis.
-   CHAD is accessed on-line at www.epa.gov/chadnet1/.  CHAD data are used in a variety of Agency and external exposure models.

-   National Human Exposure Assessment Survey (NHEXAS) was designed to evaluate comprehensive human exposure to multiple chemicals on a community and regional scale.
-   Pilot studies have been conducted with three population-based survey and sampling programs conducted in Arizona, Maryland and EPA’s Region 5.
-   Data on exposure factors from the pilot studies are available by race, ethnicity, age, gender, education and income.
-  Analysis is underway on selected exposure factors to assist in future updates of EPA’s Exposure Factors Handbook.
-   The NHEXAS exposure factor data from the pilot studies are available on a soon to be published in a user-friendly CD format.

- Air

- Soil

- Drinking water

- Food

- NHEXAS