Soil Intake Rates Based on Arsenic in Urine Data

Objective/Intended Use

The purpose of this task is to conduct an analysis of soil intake rates using environmental and biological measurements of arsenic.

Abstract

The ingestion of soil is a potential source of human exposure to environmental contaminants. Several studies have been conducted to estimate the amount of soil ingested by children. The methodology used in these studies has consisted of a mass balance using measurements of certain tracers elements in the feces and urine. There are many uncertainties associated with this approach. The present study uses an innovative approach for deriving soil intake rates. The study uses data collected for children living near a copper smelter in Washington State in the town of Ruston, and from nearby Vashon and Maury Islands. The age of the children included in the study ranged from 2 to 13 years old. Distribution of soil and dust ingestion by children will be estimated based on arsenic concentrations found in urine, soil and air samples collected during three-day visits to each household in four quarters. External peer review comments did not support the use of data to predict soil intake rates due to data variability and measurement issues. The effort as originally proposed has been terminated but collected data and analysis will be used in a new project to evaluate methodologic issues associated with measurement error and variance.

Project Status

The report has been produced. An internal and external peer review was conducted during June and July 2002. Final draft report was produced in Sep 2002. In order to address some of the peer review comments, further analysis are being conducted. Final expected in Dec. 2003.

Project Start Date

07/01/2000

Project Completion Date (Actual/Projected)

03/05/2004

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