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THE NATIONAL EXPOSURE RESEARCH LABORATORY'S CONSOLIDATED HUMAN ACTIVITY DATABASE
McCurdy, T R., G. Glenn, L. Smith, AND Y. Lakkadi. THE NATIONAL EXPOSURE RESEARCH LABORATORY'S CONSOLIDATED HUMAN ACTIVITY DATABASE. INTERNATIONAL JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 10(6):566-578, (2000).
The two main objectives of this research are (1) to improve and update and (2) to analyze the CHAD database.
For objective 1, we will
* Reconfigure the CHAD program into a completely modularized Oracle database.
* Redesign User Interface for effcient utilization of the program's capability.
* Obtain dates for those surveys that did not provide them to us, so that we can obtain associated meteorological/climatic inputs for the person-days of information without them.
* Revise the upper and lower bound delimiters in the energy expenditure distributions used for activity-specific estimates.
For objective 2, we will
* Evaluate data quality.
* Evaluate trends and activities for various subgroups.
* Identify temporal patterns for longitudinal data.
* Characterize resolution required for output for exposure and dose models.
EPA's National Exposure Research Laboratory (NERL) has combined data from 12 U.S. studies related to human activities into one comprehensive data system that can be accessed via the Internet. The data system is called the Consolidated Human Activity Database (CHAD), and it is available at http://www.epa.gov/nerl. CHAD contains 22,968 person-days of activity and is designed to assist exposure assessors and modelers in constructing population "cohorts" of people with specified characteristics that are suitable for subsequent analysis or modeling.
This paper describes the studies comprising CHAD and the various intellectual foundations that underlay the gathering of human activity pattern data. Next, it provides a brief overview of the Internet version of CHAD, and discusses how the program was formulated. Emphasis is placed on how activity-specific energy expenditure estimates were developed. Finally, the paper recommends steps that should be taken to improve the collection of activity data that would improve energy expenditure estimates and related information needed for physiologically-based exposure-dose modeling efforts.
The U.S. Environmental Protection Agency, through its Office of Research and Development, funded the development of the research described in this article under contract no. 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.