Recent Additions for 1999

December 8, 1999
Summary Of The U.S. EPA Colloquium On a Framework for Human Health Risk Assessment
EPA/600/R-99/001 and EPA/600/R-98/155
The U.S. Environmental Protection Agency (EPA) has recognized the need to develop a framework for human health risk assessment that puts a perspective on the approaches in practice throughout the Agency. The framework will be a communication piece that will lay out the scientific basis, principles, and policy choices underlying past and current risk assessment approaches and will provide recommendations for integrating/harmonizing risk assessment methodologies for all human health endpoints.

November 17, 1999
Sociodemographic Data Used For Identifying Potentially Highly Exposed Populations EPA/600/R-99/060
The document entitled Sociodemographic Data Used for Identifying Potentially Highly Exposed Populations (also referred to as the Highly Exposed Populations document), assists assessors in identifying and enumerating potentially highly exposed populations. This document presents data relating to factors which potentially impact an individual or group's exposure to environmental contaminants based on activity patterns (how time is spent), microenvironments (locations where time is spent), and other socio-demographic data such as age, gender, race and economic status.

November 17, 1999
Mercury Research Strategy (Workshop Review Draft)
NCEA-I-0710, November 1999
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.

November 15, 1999
Health Assessment Document for Diesel Emissions, SAB Review Draft EPA/600/8-90/057D
This revised draft assessment of the possible health hazards from human exposure to diesel engine exhaust emissions updates two earlier drafts (1998 and 1994) that were reviewed by the Agency's Science Advisory Board (SAB) Clean Air Scientific Advisory Committee (CASAC).

October 22, 1999
Air Quality Criteria for Particulate Matter EPA 600/P-99/002a, b, c - External Review Draft
This external review draft document is an updated revision of the Air Quality Criteria for Particulate Matter. The present external review draft critically assesses the latest scientific information relative to determining the health and welfare effects associated with exposure to various concentrations of PM in ambient air.

October 19, 1999
Annotated Bibliography Developed for the Graduate Level Introductory GIS Classes Taught at EPA EPA/R-99/088
This document represents a compilation of the bibliographies submitted by the students. The abstracts are presented in alphabetical order, by author, and have only been edited for style, not content. References that were cited by more than one student will appear as duplicates in this document. Each duplicate contains a different student's abstract.

October 15, 1999
National Ambient Air Quality Standards for Carbon Monoxide (Second External Review Draft)
EPA is now issuing a second external review draft of Air Quality Criteria for Carbon Monoxide for a 30-day public comment period and for review before the Clean Air Scientific Advisory Committee (CASAC) later in 1999. This draft contains revisions made in response to public and CASAC review comments on the February 1999 external review draft.

October 12, 1999
Strategy for Research on Environmental Risks to Children (External Peer Review Draft)
The Draft Strategy for Research on Environmental Risks to Children describes the research directions that EPA's Office of Research and Development (ORD) will follow over the next five years in its Children's Health Program.

September 30, 1999
Summary of the U.S. EPA Workshop on the Relationship Between Exposure Duration and Toxicity EPA/600/R-99/081
Current risk assessment procedures are based on overall daily exposure levels, and tend to emphasize effects resulting from continuous exposure over a lifetime. The U.S. Environmental Protection Agency's Risk Assessment Forum is beginning to examine how dose-duration relationships are or can be incorporated into the risk assessment process for less-than-lifetime exposures.

September 29, 1999
The Second National Conference on Scientific and Technical Data
Conference Announcement and Call for Papers
In conjunction with several federal science agencies, the U.S. National Committee for CODATA is organizing the second national data conference to address important multidisciplinary issues in managing and using scientific and technical (S&T) data, and to improve the visibility of those issues nationally. The main focus will be to promote the availability and usefulness of S&T data to all users, both in research and in the broader society, using examples of ground-breaking and innovative applications and highly creative partnerships.
Note: This web site is no longer available.

August 19, 1999
Toxicological Review of Chloroethane CAS No. 75-00-3
In Support of Summary Information on the Integrated Risk Information System (IRIS)
Chloroethane (CE) is a gaseous halohydrocarbon under ambient conditions. Its uses include: a topical analgesic, an anesthetic when mixed with nitrous dioxide or trichloroethane, a degreasing agent, and an agent to blow styrene in foaming operations. Anecdotal human reports indicate that recreational CE sniffing causes neurological disturbances. Nothing is known about chronic oral toxicology in animals or humans.

May 20, 1999
Toxicological Review of Vinyl Chloride, External Review Draft
The purpose of this Toxicological Review is to provide scientific support and rationale for the hazard and dose-response assessment in IRIS pertaining to chronic exposure to vinyl chloride. It is not intended to be a comprehensive treatise on the chemical or toxicological nature of vinyl chloride.

May 12, 1999
Extrapolation of the Benzene Inhalation Unit Risk Estimate to the Oral Route of Exposure
The National Center for Environmental Assessment-Washington Division, Office of Research and Development, prepared this document on the Extrapolation of the Benzene Inhalation Unit Risk Estimate to the Oral Route of Exposure. This document will serve as a source for updating the oral cancer unit risk estimate for benzene in the Integrated Risk Information System (IRIS). Given the absence of oral dose-response information, the authors propose a simple method for extrapolating benzene-induced cancer risk from the inhalation to the oral route. The method is based on the relative efficiency of benzene absorption across pulmonary and gastrointestinal barriers. Substantial literature on pulmonary absorption in humans and a few laboratory animal species exists. Data on oral absorption in humans are lacking; hence extrapolation is based on gastrointestinal absorption studies in several experimental animal species. A review of the relevant literature suggests absorption efficiencies of 50% and 100% for inhalation and oral routes of exposure, respectively. Application of these absorption factors to the current inhalation unit risk range of 2.2 X 10-6 to 7.8 X 10-6 per ug/m3 results in a proposed range for the oral unit risk of 4.4 X 10-7 to 1.6 X 10-6/5g/L.

April 30, 1999
Guidance for Conducting Health Risk Assessment of Chemical Mixtures, External Scientific Peer Review Draft
This guidance document is intended to reflect the evolution of scientific developments in the area of chemical mixtures risk assessment. Information is organized according to the type of data available to the risk assessor, ranging from data rich to data poor situations. Procedures are described for assessment using data on the mixture of concern, data on a toxicologically related mixture, as well as data on the mixture component chemicals. As new information relevant to health risk from exposure to chemical mixtures becomes available, additional guidance documents will be published.

April 5, 1999
Report of the Workshop on Selecting Input Distributions For Probabilistic Assessments
This policy establishes the Agency's position that such probabilistic analysis techniques as Monte Carlo Analysis, given adequate supporting data and credible assumptions, can be viable statistical tools for analyzing variability and uncertainty in risk assessments. The policy also identifies several implementation activities designed to assist Agency assessors with their review and preparation of probabilistic assessments.

March 19, 1999
Request for Applications for a Cooperative Agreement to Provide Assistance in Cosponsoring a National Conference on Biological Variability within and Between Children from Different U.S. Racial/Ethnicity Groups: Implications for Environmental Risk Assessment CLOSED
The National Center for Environmental Assessment - Washington Office (NCEA-W), within the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD), is issuing this "Request for Applications" (RFA) for a cooperative agreement to provide assistance in cosponsoring a national conference that will examine the scientific evidence on the question of the "Biological Variability Within and Between Children From Different U.S. Racial/Ethnicity Groups: Implications for Environmental Risk Assessment."
Note: This web site is no longer available.

March 18, 1999
Cadmium and Compounds External Review Draft
The four documents on this site are the drafts of the IRIS cadmium assessments that will undergo external peer review at a date to be announced at this site and in the Federal Register. The draft documents are: the cancer assessment, the inhalation RfC, the oral RfD, and the Toxicological Review, the latter document supporting the derivation of the former three assessments.

March 18, 1999
Air Quality Criteria for Carbon Monoxide External Review Draft
This document has been superseded by the Second External Review Draft
Recent air quality analyses show that ambient CO concentrations measured at central, fixed-site monitors in metropolitan areas of the United States have decreased significantly since the late 1980s when the last scientific review was completed. The decline in ambient CO follows approximately the decline in motor vehicle emissions. A significantly larger portion of an individual's total CO exposure may come from uncontrolled indoor and outdoor sources. Health assessment provided in this document supports and substantiates the conclusions drawn in the previous document. The greater concern has focused on subpopulations who are particularly susceptible to CO, especially the subpopulation with coronary artery disease.

March 15, 1999
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.

March 5, 1999
Call for Papers: Conference on Topics in Toxicology and Risk Assessment, April 12-15 1999 UPDATEDCLOSED
Note: This web site is no longer available.

February 18, 1999
Comparative Risk Framework Methodology and Case Study
The U.S. EPA traditionally uses a four step approach, known as the risk assessment paradigm, to assess risks posed by pollutants, whose presence is generally considered not to be beneficial to human health (NAS, 1983). This document's primary goal is to advance a methodology capable of evaluating the interdependent and disparate health outcomes and financial costs of alternative treatment systems. The secondary goal is to highlight the usefulness of the methodology through a case study presented within.

January 29, 1999
Benchmark Dose Software
The source code has been made available in C for programmers for the Benchmark Dose Software. Registration is required.

January 26, 1999
Oxygenates in Water: Critical Information and Research Needs
Identify key issues related to assessing and managing the potential health and environmental risks of oxygenate contamination of water. Oxygenates are chemicals added to fuels ("oxyfuels") to increase the oxygen content and thereby reduce emissions from use of the fuel. This document builds on and extends an earlier report, Oxyfuels Information Needs (U.S. Environmental Protection Agency, 1996), which included water issues but tended to focus more on inhalation health risk issues.

January 21, 1999
Environmental Risk Assessments of Oil and Gas Activities Using National Security and Civilian Data Sources
The national security systems (NSS) of Russia and the United States have been used for more than three decades to monitor each other's military and economic infrastructure. These high-resolution imaging systems can provide unique data for assessing a wide range of environmental issues. In 1993, Vice President Albert Gore (USA) and Prime Minister Viktor Chernomyrdin (Russia) held talks on the environmental utility of both nations' classified imagery data. As a result of these meetings, the Environmental Working Group (EWG) was formed in 1995.

January 15, 1999
Perchlorate Environmental Contamination: Toxicological Review and Risk Characterization Based on Emerging Information External Review Draft
The external peer review draft (ERD) of the document entitled Perchlorate Environmental Contamination: Toxicological Review and Risk Characterization Based on Emerging Information has been released to the expert peer review panel and the public. The ERD presents an updated human health risk assessment as well as an ecological assessment of newly performed studies on the toxicity of perchlorate. The human and ecological assessments may be used in the future to support development of a health advisory or a National Primary Drinking Water Regulation (NPDWR) and cleanup decisions at hazardous waste sites.

January 11, 1999
First Announcement for Dioxin'99: CLOSED
19th International Symposium on Halogenated Environmental Organic Pollutants and Persistent Organic Pollutants (POPs)
Note: This web site is no longer available.

January 4, 1999
Dioxin Exposure Initiative Update
Two of the articles available for downloading from our Dioxin Exposure Initiative web site were "in press" until recently. The papers are now made available though the NCEA web site at One is in the trends section and deals with modeling of 2,3,7,8-TCDD body burden, and the other one is in incinerator impacts.