The U.S. Environmental Protection Agency (EPA) has been considering a more stringent regulation of arsenic in water. A significant reduction in the maximum contaminant level (MCL) could increase compliance costs for water utilities. This book discusses the adequacy of the current EPA MCL for protecting human health in the context of stated EPA policy and provides an unbiased scientific basis for deriving the arsenic standard for drinking water and surface water.

Arsenic in Drinking Water evaluates epidemiological data on the carcinogenic and noncarcinogenic health effects of arsenic exposure of Taiwanese populations and compares those effects with the effects of arsenic exposure demonstrated in other countries—including the United States.

The book also reviews data on toxicokinetics, metabolism, and mechanism and mode of action of arsenic to ascertain how these data could assist in assessing human health risks from arsenic exposures. This volume recommends specific changes to improve the toxicity analyses and risk characterization. The implications of the changes for EPA’s current MCL for arsenic are also described.

Contents

• Subcommittee on Arsenic in Drinking Water
• Committee on Toxicology
• Board on Environmental Studies and Toxicology
• Commission on Life Sciences
• Other Reports of the Board on Environmental Studies and Toxicology
• Preface
• Executive Summary
• 1. Introduction
  • Background
  • Scientific Controversies
  • Organization Of This Report
  • References
• 2. The U.S. Environmental Protection Agency's 1988 Risk Assessment for Arsenic
  • Overview Of The EPA 1988 Special Report
  • EPA's 1988 Risk Assessment: 10 Years Later
  • Summary
  • References
• 3. Chemistry and Analysis of Arsenic Species in Water, Food, Urine, Blood, Hair, and Nails
  • Summary Of Arsenic Compounds In Water And Food
  • Relevant Chemical Considerations
  • Analysis Of Arsenic Compounds
  • Arsenic In Water
  • Arsenic In Food
  • Arsenic In Urine, Blood, Hair, And Nails
  • Summary And Conclusions
  • Recommendations
  • References
• 4. Health Effects of Arsenic
  • Cancer Effects
  • Noncancer Effects
  • Summary And Conclusions
  • Recommendations
  • References
• 5. Disposition of Inorganic Arsenic
  • Absorption
  • Biotransformation
  • Transportation, Distribution, And Elimination
  • Kinetic Model
  • Summary And Conclusions
  • Recommendations
  • References
• 6. Biomarkers of Arsenic Exposure
  • Arsenic In Urine
  • Arsenic In Blood
  • Arsenic In Hair And Nails
  • Summary And Conclusions
  • Recommendations
  • References
• 7. Mechanisms of Toxicity
  • Cancer Effects
  • Noncancer Effects
  • Summary And Conclusions
  • Recommendations
  • References
• 8. Variation in Human Sensitivity
  • Variation In Arsenic Metabolism
  • Nutritional Status
  • Summary and Conclusions
  • Recommendations
  • References
• 9. Essentiality and Therapeutic Uses
  • Definition Of Essentiality
  • Evidence For Essentiality
  • Therapeutic Uses of Arsenic
  • Summary And Conclusions
  • Recommendations
  • References
• 10. Statistical Issues
  • A Review of Dose-Response Modeling and Risk Assessment
  • The EPA 1988 Analysis
  • Problems With Risk Assessment Based On Ecological Data
  • Internal-Cancer Data From Taiwan
  • Other Issues
  • Discussion
  • Summary and Conclusions
  • Recommendations
  • References
• 11. Risk Characterization
• Addendum to Chapter 9. Experimental Conditions for Nutritional Studies with Arsenic
  • Rats and Chicks
  • References
• Addendum to Chapter 10. Table A10-1 Internal Cancer Data From Arsenic-exposure Studies Conducted In Taiwan Region Endemic To Blackfoot Disease

This project was supported by Cooperative Agreement No. CX825107-01-0 between the National Academy of Sciences and the U.S. Environmental Protection Agency. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and vice chairman, respectively, of the National Research Council.