Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations

COMMITTEE ON MEASURING LEAD IN CRITICAL POPULATIONS

BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY

COMMISSION ON LIFE SCIENCES

NATIONAL ACADEMY PRESS
WASHINGTON, D.C.
1993



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations COMMITTEE ON MEASURING LEAD IN CRITICAL POPULATIONS BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY COMMISSION ON LIFE SCIENCES NATIONAL ACADEMY PRESS WASHINGTON, D.C. 1993

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations NATIONAL ACADEMY PRESS 2101 Constitution Ave., N.W.  Washington, D.C. 20418 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 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 competencies and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, non-profit, 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 M. 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. Robert M. White 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. Robert M. White are chairman and vice chairman, respectively, of the National Research Council. The project was supported by the Comprehensive Environmental Response, Compensation, and Liability Act Trust Fund through cooperative agreement with the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service, Department of Health and Human Services. Library of Congress Catalog Card No. 93-84436 International Standard Book No. 0-309-04927-X B-152 Copyright 1993 by the National Academy of Sciences. All rights reserved. Printed in the United States of America

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Committee on Measuring Lead in Critical Populations BRUCE A. FOWLER (Chairman), University of Maryland School of Medicine, Baltimore, Md. DAVID C. BELLINGER, Children's Hospital, Boston, Mass. ROBERT L. BORNSCHEIN, University of Cincinnati Medical Center, Cincinnati, Ohio J. JULIAN CHISOLM, The Kennedy Institute, Baltimore, Md. HENRY FALK, Centers for Disease Control, Atlanta, Ga. A. RUSSELL FLEGAL, University of California, Santa Cruz, Calif. KATHRYN R. MAHAFFEY, National Institute of Environmental Health Sciences and University of Cincinnati Medical School, Cincinnati, Ohio PAUL MUSHAK, University of North Carolina, Durham, N. Car. JOHN F. ROSEN, Montefiore Medical Center, Bronx, N.Y. JOEL SCHWARTZ, U.S. Environmental Protection Agency, Washington, D.C., and Harvard School of Public Health, Cambridge, Mass. RODNEY K. SKOGERBOE (retired), Colorado State University, Loveland, Colo. Technical Advisers GEORGE PROVENZANO, University of Maryland, Baltimore, Md. JOEL POUNDS, Institute of Chemical Toxicology, Wayne State University, Detroit, Mich.

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Staff RICHARD D. THOMAS, Program Director CAROLYN E. FULCO, Staff Officer (until June 1990) MARY B. PAXTON, Staff Officer (until April 1991) NORMAN G. GROSSBLATT, Editor RUTH E. CROSSGROVE, Information Specialist and Copy Editor SHELLEY A. NURSE, Senior Project Assistant RUTH P. DANOFF, Project Assistant Sponsor: Agency for Toxic Substances and Disease Registry

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Board on Environmental Studies and Toxicology PAUL G. RISSER (Chair), University of Miami, Oxford, Ohio FREDERICK R. ANDERSON, Cadwalader, Wickersham & Taft, Washington, D.C. MICHAEL J. BEAN, Environmental Defense Fund, Washington, D.C. EULA BINGHAM, University of Cincinnati, Cincinnati, Ohio EDWIN H. CLARK, Department of Natural Resources and Environmental Control, State of Delaware, Dover, Del. ALLAN H. CONNEY, Rutgers University, N.J. JOHN L. EMMERSON, Eli Lilly & Company, Greenfield, Ind. ROBERT C. FORNEY, Unionville, Pa. ROBERT A. FROSCH, Harvard University, Cambridge, Mass. ALFRED G. KNUDSON, Fox Chase Cancer Center, Philadelphia, Pa. KAI LEE, Williams College, Williamstown, Mass. JANE LUBCHENCO, Oregon State University, Corvallis, Ore. HAROLD A. MOONEY, Stanford University, Stanford, Calif. GORDON ORIANS, University of Washington, Seattle, Wash. FRANK L. PARKER, Vanderbilt University, Nashville, Tenn., and Clemson University, Anderson, S. Car. GEOFFREY PLACE, Hilton Head, S. Car. DAVID P. RALL, Washington, D.C. LESLIE A. REAL, Indiana University, Bloomington, Ind. KRISTIN SHRADER-FRECHETTE, University of South Florida, Tampa, Fla. BAILUS WALKER, JR., University of Oklahoma, Oklahoma City, Okla. GERHARDT ZBINDEN, Eidgenossische Technisiche Hochschule Zurich, Schwerzenbach, Switzerland

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Staff JAMES J. REISA, Director DAVID J. POLICANSKY, Associate Director and Program Director for Natural Resources and Applied Ecology RICHARD D. THOMAS, Associate Director and Program Director for Human Toxicology and Risk Assessment LEE R. PAULSON, Program Director for Information Systems and Statistics RAYMOND A. WASSEL, Program Director for Environmental Sciences and Engineering

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Commission on Life Sciences THOMAS D. POLLARD (Chair), Johns Hopkins Medical School, Baltimore, Md. BRUCE M. ALBERTS, University of California, Berkeley, Calif. BRUCE N. AMES, University of California, Berkeley, Calif. J. MICHAEL BISHOP, Hooper Research Foundation, University of California Medical Center, San Francisco, Calif. DAVID BOTSTEIN, Stanford University School of Medicine, Stanford, Calif. MICHAEL T. CLEGG, University of California, Riverside, Calif. GLENN A. CROSBY, Washington State University, Pullman, Wash. LEROY E. HOOD, University of Washington, Seattle, Wash. MARIAN E. KOSHLAND, University of California, Berkeley, Calif. RICHARD E. LENSKI, University of Oxford, Oxford, United Kingdom STEVEN P. PAKES, Southwestern Medical Center, Dallas, Tex. EMIL A. PFITZER, Hoffmann-La Roche Inc., Nutley, N.J. MALCOLM C. PIKE, University of Southern California School of Medicine, Los Angeles, Calif. PAUL G. RISSER, Miami University, Oxford, Ohio JOHNATHAN M. SAMET, University of New Mexico School of Medicine, Albuquerque, N.Mex. HAROLD M. SCHMECK, JR., Armonk, N.Y. CARLA J. SHATZ, University of California, Berkeley, Calif. SUSAN S. TAYLOR, University of California at San Diego, La Jolla, Calif. P. ROY VAGELOS, Merck and Company, Inc., Whitehouse Station, N.J. TORSTEN N. WIESEL, Rockefeller University, New York, N.Y. PAUL GILMAN, Executive Director

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations This page in the original is blank.

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Other Recent Reports of the Board on Environmental Studies and Toxicology Pesticides in the Diets of Infants and Children (1993) Issues in Risk Assessment (1993) Setting Priorities for Land Conservation (1993) Protecting Visibility in National Parks and Wilderness Areas (1993) Biologic Markers in Immunotoxicology (1992) Dolphins and the Tuna Industry (1992) Environmental Neurotoxicology (1992) Hazardous Materials on the Public Lands (1992) Science and the National Parks (1992) Animals as Sentinels of Environmental Health Hazards (1991) Assessment of the U.S. Outer Continental Shelf Environmental Studies Program, Volumes I-IV (1991–1993) Human Exposure Assessment for Airborne Pollutants (1991) Monitoring Human Tissues for Toxic Substances (1991) Rethinking the Ozone Problem in Urban and Regional Air Pollution (1991) Decline of the Sea Turtles (1990) Tracking Toxic Substances at Industrial Facilities (1990) Biologic Markers in Pulmonary Toxicology (1989) Biologic Markers in Reproductive Toxicology (1989) Copies of these reports may be ordered from the National Academy Press (800) 624-6242 (202) 334-3313

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations This page in the original is blank.

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Preface Lead is a ubiquitous toxicant. It is especially toxic to young children and the fetus. Evidence gathered recently has shown that lead concentrations of less than half the previous Centers for Disease Control (CDC) guideline (30 µg/dL) can impair cognitive and physical development in children and increase blood pressure in adults. In response to that evidence, the U.S. Environmental Protection Agency has proposed setting 10 µg/dL as a maximal blood lead concentration. On the basis of the same evidence of toxic effects at 10 µg/dL, CDC has recently reduced its 1985 intervention or action concentration from 25 µg/dL to 10 µg/dL and proposed a concentration for clinical management of 20 µg/dL. Persons exposed to lead and with blood lead concentrations above 10 µg/dL are likely to number in the millions. It was estimated that in 1984 about 6 million children and 400,000 fetuses in the United States were exposed to lead at concentrations that placed them at risk of adverse health effects (i.e., blood lead concentrations of at least 10 µg/dL). Because of the potential for toxic exposures to lead of a large segment of the population, especially sensitive populations (infants, children, and pregnant women), there is a need to develop and refine methods for measuring lead in blood at the revised lower concentrations (10 µg/dL). In addition, new reliable and reproducible techniques for measuring lead in other tissues, such as bone, will also need to be developed. Methods for detecting and measuring biologic markers of low-dose exposure to lead are also needed, because the erythrocyte protoporphyrin test lacks sensitivity at blood lead concentrations below 25 µg/dL. The U.S. Agency for Toxic Substances and Disease Registry (ATSDR)

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations requested that the National Research Council (NRC) provide information on measuring environmental exposure of sensitive populations to lead. In response, the Board on Environmental Studies and Toxicology in the NRC Commission on Life Sciences formed the Committee on Measuring Lead Exposure in Critical Populations, which produced this report. Committee members have expertise in toxicology, epidemiology, medicine, and chemistry. From the beginning, the committee decided to take a broad view of its charge and to produce a report that would not only consider a variety of technical methods for measuring lead and biologic markers of lead exposure in human populations at special risk for lead toxicity, but would consider related issues, such as sources of exposures and toxicity in sensitive populations. We hope that this document meets the goals of ATSDR, which took the initiative in sponsoring this study, and the needs of the wide array of readers and regulators concerned with the impact of lead toxicity in human populations at special risk. It is clear that public-health problems associated with the misuse of lead have plagued society for several thousand years. Modern humans are estimated to have total body burdens of lead approximately 300–500 times those of our prehistoric ancestors, because lead is extensively mobilized from the earth's crust by our activities. This committee believes that the state of scientific knowledge and technical tools to deal with the lead problem are sufficiently developed to begin the process of changing these public health risks. We hope that this report will be a useful tool to those charged with shaping effective approaches for dealing with lead toxicity and thus improving the public health. The committee gratefully acknowledges the interest and support of Barry Johnson of ATSDR. We also thank George Provenzano, University of Maryland, Baltimore, and Joel Pounds, Institute of Chemical Toxicology, Wayne State University, who provided information for the committee. Finally, the committee was concerned about the extent to which societal resources are necessary to implement various environmental lead control options that are associated with the analytical methods described in this report. The committee requested that one of its members, Joel Schwartz, prepare a detailed benefit analysis of lead exposure prevention. His analysis will appear in the Journal of Environmental Research. The committee is grateful for his independent analysis of this important policy issue. This report could not have been produced without the untiring efforts of Shelley Nurse, senior project assistant. Norman Grossblatt edited the

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations report. Finally, the committee gratefully acknowledges the persistence, patience, and expertise of Carolyn E. Fulco, project director for the study until June 1990; Mary B. Paxton, project director until April 1991; and Richard D. Thomas, project director from May 1991. Dr. Thomas, an expert in toxicology and public health, provided us the guidance, perspective, and judgmental interventions necessary to bring this report to its final form. Bruce A. Fowler Chairman Committee on Measuring Lead in Critical Populations

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations This page in the original is blank.

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Contents     EXECUTIVE SUMMARY   1 1   INTRODUCTION   13     Perspective on Issues   14     Historical Background   22     Scope and Organization of the Committee Report   29 2   ADVERSE HEALTH EFFECTS OF EXPOSURE TO LEAD   31     Clinical Intoxication in Children   32     Intoxication in Adults   34     Reproductive and Developmental Effects   35     Cardiovascular Effects   72     Mechanisms of Toxicity   77     Summary   93 3   LEAD EXPOSURE OF SENSITIVE POPULATIONS   99     Historical Overview of Anthropogenic Lead Contamination   100     Source-Specific Lead Exposure of Sensitive Populations   109     Summary   139 4   BIOLOGIC MARKERS OF LEAD TOXICITY   143     Biologic Markers of Exposure   143     Biologic Markers of Effect   167

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations     Biologic Markers of Susceptibility   183     Summary   187 5   METHODS FOR ASSESSING EXPOSURE TO LEAD   191     Introduction   191     Sampling and Sample Handling   196     Measurement of Lead in Specific Tissues   197     Mass Spectrometry   205     Atomic-Absorption Spectrometry   218     Anodic-Stripping Voltammetry and Other Electrochemical Methods   223     Nuclear Magnetic Resonance Spectroscopy   224     The Calcium-Disodium EDTA Provocation Test   226     X-Ray Fluorescence Measurement   227     Quality Assurance and Quality Control   244     Summary   247 6   SUMMARY AND RECOMMENDATIONS   253     Sources of Lead Exposure   253     Adverse Health Effects of Lead   254     Markers of Lead Exposure and Effect   256     Techniques to Measure Lead Exposure and Early Toxic Effects   257     REFERENCES   263

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations

OCR for page R1
Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations This page in the original is blank.