Round 3-6c: Utilize Expert Workgroup on Lead
EPA established a workgroup of experts in lead toxicity and exposure assessment to standardize risk assessment approaches for lead-contaminated Superfund sites. The Technical Review Workgroup (TRW) is comprised of technical staff from EPA Regions, the Office of Superfund Remediation Technology Innovation (OSRTI), the Office of Research and Development (ORD), a state scientist, and other EPA programs. EPA also established the Lead Sites Workgroup (LSW), composed primarily of Regional Superfund Remedial Project Managers (RPMs), to identify and resolve key risk management issues at lead sites and to promote a nationally consistent decision making framework for lead sites across the country.
This initiative links and expands existing efforts that support lead risk assessment and policy. The TRW is responsible for collecting and distributing information, analyzing key issues, providing feedback to the Regions, and networking on lead issues. The TRW provides information and advice to Regional risk assessors and site managers on a wide range of risk assessment issues pertaining to lead contamination, but generally focuses on sites with complex or national precedent-setting lead issues. The LSW develops guidance which clarify risk management issues and provides consultation/ advice to RPMs, upon request, on unique or precedent setting issues at lead sites nationwide. Both of these groups (TRW and LSW) promote better science, share technical information, and promote national consistency across regions at contaminated lead sites.
This reforms aims to:
- Ensure that lead risk assessments are conducted consistently at sites across the country;
- Provide a national forum for discussing lead risk assessment issues, sharing the best available scientific information, and exploring the state of the science for evaluating risks due to lead contamination;
- Address site-specific concerns pertaining to the application of blood lead models and help evaluate risks to citizens (especially children) living near lead-contaminated sites; and
- Develop, review, and distribute analytical tools for lead risk assessments.
Implementation of this reform is complete.
Forthcoming products of the TRW include a directive on lead removal, additional short sheets on common issues pertaining to lead risk assessment, and a Microsoft Windows version of the IEUBK model. The TRW plans to make all of these products available on the Internet from the TRW website.
Both the TRW and the LSW attempt to hold regular conference calls and hold meetings about twice a year.
The TRW has:
- Developed a number of lead risk assessment documents, including guidance, short sheets, fact sheets, and issue papers (see Documents below);
- Posted the TRW website on the Internet, which is frequently updated with new information;
- Reviewed lead risk assessments at several sites throughout the country;
- Developed lead tools, such as the IEUBK model for predicting blood lead levels in children. In addition, the TRW has an Adult Lead Subcommittee, which developed a lead exposure risk assessment tool (spreadsheet model and guidance) for assessing risks in adult females for the protection of the fetus;
- Conducted an independent validation and verification of the IEUBK model, and produced the Validation Strategy for The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK);
- Drafted 9 issue papers and finalized 10 issue papers; and
- Held three meetings in 1997 and one in 1998, with another scheduled for January 1999. The TRW also co-sponsored a workshop on lead exposure and bioavailability in Research Triangle Park, North Carolina. In June 1999, the TRW co-sponsored a workshop on lead modeling and probabilistic risk.
- with assistance from the TRW, in August 1998, the LSW, developed an OSWER Directive entitled "Clarification to the 1994 Revised Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities" (see Documents below). This directive clarified 4 major issue areas encountered at lead sites and will result in consistent decisions in these areas at lead sites across the country; and
- is currently developing 5 issue papers which will be incorporated into additional guidance in the future.
The TRW facilitates communication of the best science pertaining to lead risk assessment. The TRW achieves this by posting its products on the Internet and staffing a technical support center. The TRW website provides the most current information pertaining to lead risk assessment, as well as tools for conducting lead risk assessments. In FY97, the TRW technical support center responded to 12 questions concerning the IEUBK model or other related issues and supplied TRW documents to 19 requestors. Since January 1998, the TRW technical support center has responded to more than 70 requests for assistance. [FY97 Success]
IRS Day Care Facility
The TRW conducted a review of the Internal Revenue Service Day Care Facility in Washington, DC. [FY97 Success]
Site-Specific Lead Risk Assessments
The TRW reviewed data on bioavailability, lead speciation in the environment, and lead ingestion inputs at several sites. TRW analysis of risk assessments influenced cleanup decisions at the following sites: the Palmerton Zinc site in Carbon County, Pennsylvania; the California Gulch site, in Leadville, Colorado; the Remington Arms site in Bridgeport, Connecticut; the Sandy Smelter site in Sandy, Utah; the Greenbay Paint Sludge site in Michigan; the Jack's Creek site in Maitland, Pennsylvania; and the Illinois Central site in McComb, Mississippi. [FY97 Success]
The TRW assisted the State of Ohio in creating the "Voluntary Action Program Support Document for the Development of General Numerical Standards and Risk Assessment Procedures;" advised the State of Georgia Voluntary Action Program on the correct methodology for applying the adult lead methodology; and provided general recommendations pertaining to soil-to-dust ratios to the State of Washington. [FY97 Success]
NOTE: Each of the links below points to the Products page of the TRW website. The documents can be downloaded from that page.
Title: Administrative Reforms for Lead Risk Assessment
Date: April 17, 1996
Document #: EPA 540-F-97-015, OSWER 9200.4-20, NTIS PB97-963226
Synopsis: This memorandum includes a request for information on residential lead risk assessments and a draft plan for achieving these goals. EPA received comments on the draft plan at the end of May, 1996.
- Download in PDF Format (37 pages, 1081K)
Date: August, 1998
Document #: EPA 540-F-98-030, OSWER 9200.4-27
Synopsis: This document clarifies the existing 1994 "Revised Interim Soil Lead (Pb) Guidance for CERCLA Sites and RCRA Corrective Action Facilities" (see below).
Title: Fact Sheet: Technical Review Workgroup for Lead of the U.S. Environmental Protection Agency
Date: June 1997
Synopsis: This fact sheet provides general information about the Technical Review Workgroup for Lead, its members, and its role within EPA.
Title: Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK)
Date: February 1994
Document #: OSWER 9285.7-15-1
Synopsis: This guidance manual describes key features of the conceptual underpinnings of the IEUBK model, its evolution and development, its capabilities, and its limitations. The manual offers guidance on the use of the model as a risk assessment tool to ensure consistent application of the model at lead-contaminated sites.
Title: Recommendations of the Technical Review Workgroup (TRW) for Lead for an Interim Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil
Date: December 1996
Synopsis: This report provides technical recommendations of the TRW for the assessment of adult lead risks using this methodology. An overriding objective in the development of this methodology was the immediate need for a scientifically defensible approach for assessing adult lead risks. The report describes the methodology for assessing risks associated with non-residential adult exposure to lead in soil.
Title: Revised Interim Soil Lead (Pb) Guidance for CERCLA Sites and RCRA Corrective Action Facilities
Date: August 1994
Document #: EPA 540-F-94-043, OSWER 9355.4-12, NTIS PB94-963282
Synopsis: This interim directive establishes a streamlined approach for determining protective levels for lead in soil at CERCLA sites and RCRA facilities. It describes how to develop site-specific preliminary remediation goals (PRGs) at CERLCA sites and media cleanup standards (MCSs) at RCRA facilities. The residential screening level for lead described in this directive was calculated using the Agency's IEUBK model.
Title: Technical Support Document for the Integrated Exposure Uptake Biokinetic Model for Lead in Children
Date: December 1994
Document #: OSWER 9285.7-15-1, NTIS PB93-963510
Synopsis: This document describes in detail the basis for the parameters used in the IEUBK model. It is a supplement to the guidance manual published in February 1994, providing an interpreted set of equations which have been simplified for clarity. The IEUBK model has been recommended as a risk assessment tool to support the implementation of the OSWER directive on revised soil lead guidance for CERCLA sites and RCRA facilities.
Title: Validation Strategy for The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK)
Date: December 1994
Document #: EPA 540-R-94-039, OSWER 9285.7-21, NTIS PB94-963504
Synopsis: This strategy document for the IEUBK model primarily addresses the comparison of model predictions of blood lead levels with those observed in epidemiological studies in which environmental lead levels were also characterized. The objective is to describe the model's performance and assist users in better understanding its strengths and limitations. The model is the recommended risk assessment tool for lead-contaminated sites.