LEAD EXPOSURE AND CHILD DEVELOPMENT An International Assessment LEAD EXPOSURE AND CHILD DEVELOPMENT An International Assessment Edited by M.A. Smith Department of Child Psychiatry Institute of Child Health Hospital for Sick Children Great Ormond Street, London, UK L.D. Grant Director, Environmental Criteria and Assessment Office Office of Health and Environment Assessment US Environmental Protection Agency Research Triangle Park NC 27711, USA A.I. Sors Commission of the European Communities Directorate-General for Science, Research and Development Environment Research Programme Rue de la Loi 200 B-1049 Brussels, Belgium Published for the Commission of the European Communities and the US Environmental Protection Agency by .w. KLUWER ACADEMIC PUBLISHERS ~ DORDRECHT/BOSTON/LONDON Distributors for the United States and Canada: Kluwer Academic Publishers, PO Box 358, Accord Station, Hingham, MA 02018-0358, USA for all other countries: Kluwer Academic Publishers Group, Distribution Center, PO Box 322, 3300 AH Dordrecht, The Netherlands British Library Cataloguing in Publication Data Lead exposure and child development. 1. Healthy children. Effects of lead pollutants. Effects on health of children I. Smith, Marjorie A II. Grant, Lester D. III. Sors, AI. N. Commission of the European Communities V. United States, Environmental Protection Agency 613.1 ISBN-13:978-94-0l0-6868-0 e-ISBN-13:978-94-009-0847-5 DOl: 10.1007/978-94-009-0847-5 Library of Congress Cataloging-in-Publication Data Lead exposure and child development : an international assessment I edited by M.A Smith, L.D. Grant, and AI. Sors. p. em. "Published for the Commission of the European Communities and the US Environmental Protection Agency." Includes bibliographies and index. ISBN-13:978-94-0l0-6868-0 : £45.00 (U.K. : est.) 1. Lead-poisoning in children - Congresses. 2. Child development - Congresses. I. Smith, M.A. (Marjorie A) II. Grant, Lester D. III. Sors, AI. (Andrew I.) N. Commission of the European Communities. V. United States. Environmental Protection Agency. [DNLM: 1. Child Development Disorders - chemically induced. 2. Environmental Exposure. 3. Lead Poisoning - in infancy & childhood. QV 292 L43035] RA1231.L4W78 1988 362.1'989298 - dc19 DNLM/DLC for Library of Congress 88-37512 CIP Copyright ©ECSC-EEC-EAEC. Brussels - Luxembourg; EPA. USA; 1989 Softcover reprint of the hardcover 1st edition 1989 Legal notice Neither the Commission of the European Communities nor the Environmental Protection Agency nor any person acting on behalf of these bodies is responsible for the use which might be made of the following information. Publication No. EUR 11085 of the Commission of the European Communities Directorate-General Telecommunications, Information Industries and Innovation Scientific and Technical Communication Unit All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission from the publishers, Kluwer Academic Publishers BV, PO Box 17, 3300 AA Dordrecht. The Netherlands. Published in the United Kingdom by Kluwer Academic Publishers, PO Box 55, Lancaster, UK. Kluwer Academic Publishers BV incorporates the publishing programmes of D. Reidel. Martinus Nijhoff, Dr W. Junk and MTP Press. Contents Preface ix Section 1: STATE-OF-THE-ART REVIEWS 1.1 The effects of low-level lead exposure on children M.A. Smith 3 1.2 Effects of low-level lead exposure on paediatric neurobehavioural development: current findings and future directions L.D. Grant and ].M. Davis 49 Section 2: INTRODUCTORY PAPERS 2.1 Lead: ancient metal - modem menace? G. Kazantzis 119 2.2 Biological monitoring of lead exposure in children: overview of selected biokinetic and toxicological issues P. Mushak 129 Section 3: CROSS-SECTIONAL EPIDEMIOLOGICAL STUDIES OF CHILDREN Introduction 148 3.1 Lead exposure and children's intellectual performance: the Institute of Child Health / Southampton study S.]. Pocock, D. Ashby and M.A. Smith 149 v LEAD EXPOSURE 3.2 Child-caregiver environmental factors related to lead exposure and IQ S.R. Schroeder 166 3.3 Blood lead and other influences on mental abilities - results from the Edinburgh lead study G.M. Raab, M. Fulton, G.o.B. Thomson, D.P.H. Laxen, R. Hunter and W. Hepburn 183 3.4 The Birmingham blood lead studies P. G. Harvey, M. W. Hamlin, R. Kumar, ]. Morgan, A. Spurgeon and T. Delves 201 3.5 Psychometric intelligence deficits in lead-exposed children A. Hatzakis, A. Kokkevi, C. Maravelias, K. Katsouyanni, F. Salaminios, A. Kalandidi, A. Koutselinis, C. Stefanis and D. Trichopoulos 211 3.6 Evaluation of different biological indicators of lead exposure related to neuropsychological effects in children G. Vivoli, M. Bergomi, P. Borella, G. Fantuzzi, L. Simoni, D. Catelli, N. Sturloni, G.B. Cavazzuti, R. Montorsi, R. Campagna, A. Ta mpieri and P.L. Ta rtoni 224 3.7 Neuropsychological profile of children in relation to dentine lead level and socioeconomic group O.N. Hansen, A. Trillingsgaard, 1. Beese, T. Lyngbye and P. Grandjean 240 3.8 A regression analysis study of the Brussels lead and IQ data R.J.G. Cluydts and A. Steenhout 251 3.9 The Sydney study of health effects of lead in urban children w.G. McBride, c.]. Carter, ].R. Bratel, G. Cooney and A. Bell 255 3.10 Follow-up studies in lead-exposed children G. Winneke, W. Collet, U. Kramer, A. Brockhaus, T. Ewert and C. Krause 260 3.11 Automated assessment of attention, vigilance and learning in relation to children's lead levels W. Yule, R. Lansdown, M. Urbanowicz, D. Muddiman and J. Hunter 271 3.12 Electrophysiological assessment of sensory and cognitive function in children exposed to lead: a review D.A. Otto 279 3.13 Type II fallacies in the study of childhood exposure to lead at low dose: a critical and quantitative review H.L. Needleman and D. C. Bellinger 293 vi CONTENTS Section 4: PREGNANCY OUTCOME, NEONATAL AND PROSPECTIVE STUDIES Introduction 306 4.1 Effects of prenatal lead exposure on infant size at birth RL. Bornschein, ]. Grote, T. Mitchell, P.A. Succop, KN Dietrich, KM. Krafft and P.B. Hammond 307 4.2 Neurobehavioural effects of foetal lead exposure: the first year of life KN Dietrich, KM. Krafft, M. Bier, O. Berger, P.A. Succop and RL. Bomschein 320 4.3 The Port Pirie cohort study - cumulative lead exposure and neurodevelopmental status at age 2 years: do HOME scores and maternal IQ reduce apparent effects of lead on Bayley mental scores? G. V. Vimpani, P.A. Baghurst, NR Wigg, E.F. Robertson, A.]. McMichael and RR Roberts 332 4.4 Low-level lead exposure and early development in socioeconomically advantaged urban infants D. Bellinger, A. Leviton, C Watemaux, H. Needleman and M. Rabinowitz 345 4.5 Lead related birth defects: some methodological issues CB. Emhart, G. Brittenham, M.R Marler and R.]. Sokol 357 4.6 A prospective study of the results of changes in environmental lead exposure in children in Glasgow M.R Moore, 1. W.R Bushnell and Sir A. Goldberg 371 4.7 Environmental lead, reproduction and infant development ]. Graziano, D. Popovac, M. Murphy, A. Mehmeti, J. Kline, G. Ahmedi, P. Shrout, Z. Zvicer, G. Wasserman, E. Gashi, Z. Stein, B. Rajovic, L. Belmont, B. Colakovic, R Bozovic, R. Haxhiu, L. Radovic, R Vlaskovic, D. Nenezic and N Loiacono 379 4.8 Effects of lead on neurobehavioural development in the first thirty days of life S.]. Rothenberg, L. Schnaas, C].N Mendes and H. Hidalgo 387 Section 5: ANIMAL STUDIES AND MECHANISMS Introduction 398 5.1 The lessons of lead for behavioural toxicology D.A. Cory-Slechta 399 vii LEAD EXPOSURE 5.2 Neurobehavioural and electrophysiological effects of lead in rats and monkeys H. Lilienthal, C Munoz, G Winneke, C Lenaerts and R. Hennekes 414 5.3 Behavioural effects of low-level developmental exposure to lead in the monkey D.C Rice 427 5.4 The effects of chronic low-level lead exposure on the early structuring of the nervous system CM. Regan, GR. Cookman, G.]. Keane, W. King and S.£. Hemmens 440 5.5 Studies on lead and blood-brain barrier function in the developing rat D. Pelling, R.]. Hargreaves and S.R. Moorhouse 453 Section 6: EXTENDED ABSTRACTS OF POSTERS 6.1 Low-level lead exposure and intelligence in the early preschool years CB. Ernhart and M. Morrow- Tlucak 469 6.2 Which measures of lead burden best predict a child's two- year mental development? M. Rabinowitz, D. Bellinger and A. Leviton 475 6.3 Recent observations concerning the relationship of blood lead to erythrocytic protoporphyrin P.A. Succop, P.B. Hammond, R.L. Bornschein, S.B. Roda and RD. Greenland 477 Section 7: SUMMARY OF WORKSHOP DISCUSSIONS, AND FUTURE DIRECTIONS 485 Alphabetical list of participants 499 Index 505 viii Preface This book arises out of a workshop on lead exposure and child development which was held at the University of Edinburgh on 8th-12th September 1986. It was organized jointly by the Commission of the European Communities (CEC) and the US Environmental Protection Agency (EPA), in association with the UK Department of the Environment and the Scottish Home and Health Department. It brought together most of the internationally recognized groups working on the effects of lead exposure on child development including child psychologists, psychiatrists, neurologists, epidemiologists, toxicologists, stati- sticians, and medical practitioners. One of the unique features of the meeting was that it included workers from initially separate fields of lead research, in particular those undertaking studies in infants and in older children, and those carrying out behavioural research in animals, as well as those undertaking biochemical studies on mechanisms of lead effect. The structure of this book reflects the main elements of the meeting. As such it includes three main sections. The first consists of two major state-of- the-art reviews, and two invited introductory papers. The reviews were prepared for the organizers of the conference by two of the Editors. The objectives were to assess critically the state of current knowledge in this field and to provide a scientific basis both for policy decisions and for further research. The review prepared by Marjorie Smith for the Commission of the European Communities focusses on methodological and design issues, and summarizes our present scientific knowledge in this area. Here, the emphasis is on cross-sectional epidemiological studies primarily carried out within the countries of the European Community. The review prepared by Lester Grant of the US Environmental Protection Agency reflects considerations of environmental policy, and reviews the studies particularly from the US perspective. It is recognized that there are some areas of overlap between these two reviews; however, it was considered useful to examine some key issues from two different perspectives. The second and by far the largest part of this book includes papers containing presentations by the various invited groups on their findings. A substantial proportion of the work reported was carried out under contract to the CEC or to the EPA and other US-federal agencies, respectively. The ix LEAD EXPOSURE presentations were organized under three headings: (1) Cross-sectional Epidemiological Studies of Children, (2) Pregnancy Outcome, Neonatal and Prospective Studies, and (3) Animal Studies and Mechanisms; these headings have been maintained in the present volume. The final short section is an attempt by the Editors to synthesize the main issues which were raised during the extensive discussion sessions at the end of the meeting. Based upon this, some geheral guidelines for the directions of future research are also suggested. The organizers consider that their original objectives for the meeting and for the resulting book have been fully satisAed. The meeting provided a basis for a comprehensive assessment of the critical scientiAc issues, an extensive presentation and discussion of the latest original research findings, as well as important guidelines for policymakers. It should be noted that all three main sections of this book have been restructured as well as revised during the course of its preparation for publication. It is hoped that this final product represents a unique international assessment of the current knowledge in this Aeld. As joint organizers of this workshop, the Commission of the European Communities and the US Environmental Protection Agency are very pleased to have been able to collaborate in this important initiative. They also wish to acknowledge, with gratitude, the financial and administrative support of the UK Department of the Environment and the Scottish Home and Health Department, and the excellent local organization undertaken by Dr Mary Fulton and her colleagues of the Department of Community Medicine at the University of Edinburgh. M.A. Smith L.D. Grant A.I. Sors December 1988 X Section 1 STATE-OF-THE-ART REVIEWS