Toxicological Review of Barium and Compounds

LIST OF TABLES

1-1. 

Physical and chemical properties of barium and selected barium compounds  . . . . . . . . . 5

4-1. 

Incidence and mean severity scores for nephropathic lesions in B6C3F1 

mice exposed to barium chloride dihydrate in drinking water  . . . . . . . . . . . . . . . . . . . . 19 

5-1. 

Effects of subchronic and chronic oral barium exposure on rodents . . . . . . . . . . . . . . . . 44 

5-2. 

Nephropathy in B6C3F1 mice chronically exposed to barium in drinking water  . . . . . . 45 

5-3. 

Comparison of best fitting models fits and benchmark doses for increased risk of

nephropathy  in  mice  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

LIST OF FIGURES

B-1. 

Third degree multistage for increased incidence of nephropathy in male mice  . . . . . . B-2 

B-2. 

Output for multistage model for increased incidence of nephropathy in male mice  . . . B-3 

v 

---

FOREWORD 

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 barium 

and soluble compounds.  It is not intended to be a comprehensive treatise on the chemical or 

toxicological nature of barium. 

In Section 6, Major Conclusions in the Characterization of Hazard and Dose Response, 

EPA has characterized its overall confidence in the quantitative and qualitative aspects of hazard 

and dose response by addressing knowledge gaps, uncertainties, quality of data, and scientific 

controversies.  The discussion is intended to convey the limitations of the assessment and to aid 

and guide the risk assessor in the ensuing steps of the risk assessment process.  

For other general information about this review or other questions relating to IRIS, the 

reader is referred to EPA’s Risk Information Hotline at 202-566-1676. 

vi 

---

AUTHORS, CONTRIBUTORS, AND REVIEWERS 

CHEMICAL MANAGERS/AUTHORS

1 

Stiven Foster, M.S. (2005)

National Center for Environmental Assessment

Office of Research and Development

U.S. Environmental Protection Agency 

Washington, DC 

Harlal Choudhury, D.V.M., Ph.D., D.A.B.T. (1998) 

National Center for Environmental Assessment 

Office of Research and Development 

U.S. Environmental Protection Agency 

Cincinnati, OH 

CONTRIBUTING AUTHORS 

Joan Colman, Ph.D. (1998) 

Senior Scientist 

Syracuse Research Corporation 

Syracuse, NY 

Lisa Ingerman, Ph.D. (1998) 

Senior Scientist 

Syracuse Research Corporation 

Portland, OR 

Phillip Robbins, M.S. (1998) 

Scientist 

Syracuse Research Corporation 

Cincinnati, OH 

REVIEWERS 

This document and the accompanying IRIS Summary have been peer reviewed by EPA 

scientists and independent scientists external to EPA.  Comments from all peer reviewers were 

evaluated carefully and considered by the Agency during the finalization of this assessment. 

During the finalization process, the IRIS Program Director achieved common understanding of 

the assessment among the Office of Research and Development; Office of Air and Radiation; 

Office of Prevention, Pesticides, and Toxic Substances; Office of Solid Waste and Emergency 

Response; Office of Water; Office of Policy, Economics, and Innovation; Office of Children’s 

Health Protection; Office of Environmental Information; and EPA’s regional offices. 

1

 Dates pertain to the version of the IRIS assessment.  The oral reference dose added to 

IRIS in 1998 was revised in 2005. 

vii 

---

AUTHORS, CONTRIBUTORS, AND REVIEWERS (continued) 

INTERNAL EPA REVIEWERS 

Harlal Choudhury, D.V.M., Ph.D., D.A.B.T. (2005) 

National Center for Environmental Assessment 

Office of Research and Development 

U.S. Environmental Protection Agency 

Cincinnati, OH 

Lynn Flowers, Ph.D., D.A.B.T. (2005) 

National Center for Environmental Assessment 

Office of Research and Development 

U.S. Environmental Protection Agency 

Washington, DC 

Edward Ohanian, Ph.D.  (1998) 

Senior Health Scientist 

Health and Ecological Criteria Division 

Office of Water 

U.S. Environmental Protection Agency 

Washington, DC 

Vanessa Vu, Ph.D. (1998)

Director, Risk Assessment Division

Office of Prevention, Pesticides, and Toxic Substances

U.S. Environmental Protection Agency 

Washington, DC 

EXTERNAL PEER REVIEWERS 

Eliseo Guallar, M.D., Dr. Ph. (2005) 

Johns Hopkins Medical Institutions 

Baltimore, MD 

Y. James Kang, D.V.M., Ph.D. (2005)

University of Louisville

Louisville, KY

Lawrence Lash, Ph.D. (2005) 

Wayne State University 

Detroit, MI 

viii 

---

AUTHORS, CONTRIBUTORS, AND REVIEWERS (continued) 

Paul Mushak, Ph.D. (1998 and 2005)

PB Associates

Durham, NC

Robert G. Tardiff, Ph.D., ATS (2005)

The Sapphire Group, Inc.

Washington, DC

Marvin Goldman, Ph.D.  (1998)

University of California, Davis

Davis, CA

Arthur Gregory, Ph.D., D.A.B.T.  (1998)

Techto Enterprises

Luray, VA

Summaries of the external peer reviewers’ comments and public comments and the 

dispositions of their recommendations are in Appendices A-1 and A-2. 

ix 

---