What is an appropriate soil ingestion rate (IR) for a construction scenario (i.e., soil contact-intensive scenario)?
The TRW recommends 50 mg/day as the default ingestion rate for indoor workers. This value is cited in the ALM guidance (Recommendations of the Technical Review Workgroup for Lead for an Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil, December 1996), and the Exposure Factors Handbook (U.S. EPA, 1997). A reasonable default value that has been commonly used as a central tendency estimate for contact-intensive adult scenarios (such as an agricultural or construction worker) is 100 mg/day. There is high uncertainty in soil ingestion rates for adults due to sparse empirical data on adult soil ingestion rates. There are data available from two studies (Calabrese et al., 1990; Calabrese et al., 1997), each conducted concurrently with a study of childhood soil ingestion rates, but neither study group targeted a population expected to engage in frequent contact with soil, such as construction workers. The purpose of the studies was to verify the tracer mass balance m
The TRW recommends 50 mg/day as the default ingestion rate for indoor workers. This value is cited in the ALM guidance (Recommendations of the Technical Review Workgroup for Lead for an Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil, December 1996), and the Exposure Factors Handbook (U.S. EPA, 1997). A reasonable default value that has been commonly used as a central tendency estimate for contact-intensive adult scenarios (such as an agricultural or construction worker) is 100 mg/day.
