Recent Additions for 2001

The model MFFRST, short for Metal Finishing Facility Risk Screening Tool, is a user-friendly pc-based computer tool which allows an individual to evaluate the potential exposures and health risks to workers and nearby residents from emissions of contaminants into air from individual metal finishing facilities. Available for downloading at this new site are the MFFRST technical supporting document, six published articles on the development, testing, and application of MFFRST, and of course, the pc-based model itself.

FR Notice: Intent to Issue Final Revised Guidelines for Carcinogen Risk Assessment in 2002

FR Notice EPA announces its intent to proceed to issue final revised Guidelines for Carcinogen Risk Assessment in 2002. The Agency is soliciting additional scientific information and comments that could assist us in completing the final Guidelines.

This technical support document is aimed at informing decision makers, general academia, and the public on the scientific foundation and relevance to the United States of the Stockholm Convention on Persistent Organic Pollutants (POPs). Under this treaty, countries commit to reduce and/or eliminate the production, use, and release of the twelve POPs of greatest concern to the global community, and to establish a mechanism by which additional substances may be added to the treaty in the future. The Stockholm Convention was signed by Governor Whitman on behalf of the United States in May, 2001, and has been identified by President Bush as a priority for submission to the U.S. Congress for ratification. This report summarizes data available in the peer reviewed literature on the twelve POPs, and provides an overview of the risks posed to United States ecosystems and/or citizenry. The EPA is currently seeking comments from the public on this draft report. The comment period is open until Friday, January 25, 2002.

This is the report of a 1998 workshop sponsored by EPA and the U.S. Department of Interior on the application of dioxin toxicity equivalence factors (TEFs) to fish and wildlife. TEFs are tools for estimating the combined risks from exposure to complex mixtures of polychlorinated dioxins (PCDDs), furans (PCDFs), and biphenyls (PCBs). The workshop concluded that the toxicity equivalence methodology is appropriate for evaluating risks to fish, birds, and mammals.

Note: this report is not EPA's reassessment of the health risks from dioxin. For more information about the dioxin reassessment, please visit: www.epa.gov/dioxin

On October 10 and 11, the National Center for Environmental Assessment (NCEA) will host at its Washington, DC offices a review and site visit by the Office of Research and Development's (ORD) Board of Scientific Counselors (BOSC) Subcommittee for NCEA. In preparation for the Subcommittee's review, the BOSC requested that each ORD national laboratory and center respond to 18 questions. NCEA has developed a response to these questions and has submitted the responses to the NCEA-BOSC Subcommittee. NCEA's responses will help the Subcommittee to gauge the progress of the Center since its 1997 review and to evaluate science and planning activities that NCEA has developed to address the priorities and directions included in the EPA and ORD Strategic Plans.

NCEA Web Site Updated and Redesigned

The NCEA Web Site has been updated and redesigned to improve the presentation of information and make use of better and more powerful search features. The redesigned site uses EIMS (Environmental Information Management System) to store and search NCEA information and to dynamically generate web pages based on a user's request for the information. Once a user has located a document or tool of interest by drilling down to an abstract/summary page, downloads (or viewing) of the complete document/tool are accessible by clicking on the Downloads/URL Links item on the sidebar. Regular users of the site may wish to bookmark the What's New page where all additions to the site are announced, and/or the Topics/All Topics page (linking to all types of site information including publications, databases and tools, and projects), or the Publications/Topics page. We welcome comments and suggestions that will help us improve the NCEA web site to better meet the needs of its users.

This assessment presents EPA's most current evaluation of the potential health risks from exposure to trichloroethylene (TCE). TCE exposure is associated with several adverse health effects, including neurotoxicity, immunotoxicity, developmental toxicity, liver toxicity, kidney toxicity, endocrine effects, and several forms of cancer. This assessment evaluates the potential health risks of TCE in light of the available information and analyses pertinent to mode of action, uncertainty, human variation, and cumulative risks.

This report describe the sources, emission, environmental fate and exposures for Trichloroethylene (TCE), some of its metabolites, and some other chemicals known to produce identical metabolites. It is intended to be used as a resource document for risk assessors inside and outside the Agency.

EPA is providing for public information a draft Toxicological Review, and draft IRIS Summary, and to external peer reviewers for EPA's health assessment of acetone (CAS No. 67-64-1). These documents are provided for public viewing during an external scientific peer review period.

Statistical analyses of the human health effects of airborne pollutants based on aggregate population time-series data have often relied on ambient concentrations of pollutants measured at one or more central sites in a given metropolitan area. This report revisits the practice of multiple-site averaging. The results are drawn from an analysis examining simultaneous mapping of population density and ambient O₃ concentrations on the scale of a single metropolitan area. Because of the ready availability of data associated with a related research effort, the city selected for this analysis was Phoenix, AZ.

A technical panel convened under the EPA Risk Assessment Forum has been working to develop a Framework for Cumulative Risk Assessment. Building from the Agency's growing experiences, this Framework is intended to identify the basic elements of the cumulative risk assessment process. This preliminary draft of the Framework for Cumulative Risk Assessment is being made available at this time for the purpose of peer consultation. At the completion of the peer consultation process, the document will be revised and then reviewed by the Agency's Science Advisory Board (SAB). The final framework document will reflect the SAB comments and will require review and approval by the Agency's Science Policy Council.

Contaminated water can lead to the volatilization of chemicals to residential indoor air; however, previous research has focused on one source, namely showers. This report presents the results of a series of experiments conducted to determine emissions from four sources of water use in a household (showers, bathtubs, washing machines, and dishwashers). Mass transfer coefficients and chemical stripping efficiencies were determined using these four sources and five tracer chemicals (acetone, ethyl acetate, toluene, ethylbenzene, and cyclohexane).

A Request for Applications for Cooperative Agreements to Provide Assistance to State/Tribal/Other Local Environmental Protection Agencies to Conduct Location-Specific Assessments of the Impacts of Climate Change and Variability on Aquatic Ecosystems and Water Quality.

The 1986 Guidelines for the Health Risk Assessment of Chemical Mixtures represent the EPA's science policy and are a procedural guide for evaluating data on the health effects from exposures to chemical mixtures. This supplementary guidance provides additional procedures and more detail on the broad principles and procedures of the 1986 Guidelines.

This document is being developed to supplement the EPA Guidelines for Ecological Risk Assessment of 1998. It is designed to help decisionmakers work with risk assessors, stakeholders, and other analysts to plan for ecological risk assessments that will effectively inform the decisions to be made.

Effective prioritization of streams for protection or restoration relies in part on the ability to scientifically determine the causes of changes in condition. The ORD and OW have developed a process to logically gather information and present evidence for the identification of principal causes of biological impairment. The process was recently published in the Stressor Identification Guidance Document (2001). The Stressor Identification Guidance was a collaborative effort with involvement by the Office of Water's OST and OWOW, and multiple ORD laboratories and centers including the National Center of Environmental Assessment (NCEA). Workgroup chairs were Susan Cormier (ORD-NERL ) and Donna Reed-Judkins (OW-OST); authors also included Glenn Suter and Susan Norton (ORD-NCEA).

This database documents congener-specific emissions and environmental releases of polychlorinated dibenzo-para-dioxins (CDDs) and polychlorinated dibenzofurans (CDFs) from known source activities in the United States.

The Wildlife Contaminants Exposure Model (WCEM) has been released for beta-testing. The WCEM is designed to make wildlife exposure modeling more consistent, transparent and efficient. It is suitable for any screening-level risk assessment exercise requiring an estimate of wildlife exposure to organic or inorganic compounds but can also support more detailed risk characterizations.

EPA is now issuing a second external review draft of Air Quality Criteria for Particulate Matter for a 90-day public comment period and for review before the Clean Air Scientific Advisory Committee (CASAC). This draft contains revisions in response to public and CASAC review comments on the October 1999 external review draft.

This latest version of BMDS contains new continuous Polynomial (v2.1), Power (v2.1) and Hill (v2.1) models, new dichotomous Multistage (v2.1), Weibull (v2.1) and Gamma (v2.2) models, and an improved user interface. The new models are more compact and stable (will converge on BMD and BMDL solutions more often). The user interface upgrades are described in the new help manual (PDF format) for version 1.3 available from the BMDS web site and in the readme.txt file that is distributed with the upgrade.

An interagency conference sponsored by Tri-Service (Air Force, Army, Navy) Toxicology; the U.S. EPA, Office of Research and Development, National Center for Environmental Assessment; Agency for Toxic Substances and Disease Registry, the Division of Toxicology; the National Institute of Environmental Health Sciences; and the Food and Drug Administration. The conference is held with the cooperation of the National Research Council/National Academy of Sciences and the National Institute for Occupational Safety and Health.

EPA is hereby providing for public information a draft Toxicological Review, draft IRIS Summary, and charge to external peer reviewers for EPA's health assessment of Boron.

Exposure Factors Program

The development of the latest version of the Exposure Factors Handbook has brought to light the need for a more comprehensive program that addresses issues related to exposure factors. The

need for the most up-to-date and accurate data on exposure factors used in assessing exposure to contaminants in the environment is of high priority to exposure assessors throughout the U.S. The completion of the Exposure Factors Handbook has only been the first step in fulfilling this need. This web page is intended to provide a focal point where the most current information

and data on exposure factors can be found.

EPA is releasing the final report of an evaluation

of IRIS concerning documentation of data variability and uncertainty, in response to a Congressional directive contained in HR 106-379. The final report reflects EPA's Science Advisory Board review.

The Mercury Research Strategy describes a research program that provides information, methods, models, and data to address key scientific questions of greatest concern to EPA, reducing uncertainties currently limiting the Agency's ability to assess and manage mercury and methylmercury risks. The Office of Research and Development expects that the research strategy will be used to guide the development of a more detailed implementation plan. It will act as a resource for EPA managers who must make decisions about future research priorities and budgets.

Post Doctoral Positions available in ORD/National Center for Environmental Assessment

As part of the U.S. Environmental Protection Agency's (EPA's) effort through its Office of Research and Development (ORD) to recruit post-doctoral candidates to fill positions in EPA laboratories and centers, the National Center for Environmental Assessment (NCEA) is seeking post-doctoral candidates from a wide range of disciplines for its divisions in Washington, DC, Research Triangle Park,NC, and Cincinnati, OH.