ENVIRONMENTAL RESEARCH 51, 1--24 (1990) REVIEW 1989 Alice Hamilton Lecture 1 Lead and Human Health: Background and Recent Findings MORTON LIPPMANN New York University Medical Center, Institute of Environmental Medicine, Tuxedo, New York 10987 Received March 22, 1989 This paper, prepared in tribute to Dr. Alice Hamilton on her 120th birthday, reviews her pioneering studies of occupational lead poisoning and its control, her largely unheeded warnings about the possible consequences of widespread lead exposure to the general public through the use of leaded fuel, and the results of recent studies of human exposure to and health effects of lead in the general environment. Evidence is presented for dose-related non-threshold effects for children with blood lead concentrations below 25 vLg/dl for a variety of effects including verbal IQ; mental development; physical size; and age at phys- ical milestones such as first steps, hearing thresholds, and posturat sway. For adults, various studies have produced associations between blood pressure and blood lead concentrations below 35 wg/dl, suggesting possible effects on cardiovascular health. While the biological mechanisms responsible for these effects remain poorly understood, recent and current efforts to reduce exposure to lead by the virtual elimination of lead in gasoline and food packaging show that we have learned one of Dr. Hamilton's important lessons, i.e., that the most effective means of reducing excessive exposures are through control of the environ- mental sources. © 1990 AcademicPress, Inc. INTRODUCTION The invitation to present the second Alice Hamilton lecture led me to reread her autobiography (Hamilton, 1943) Exploring the Dangerous Trades (Fig. 1) which, in turn, led me to select lead's effects on human health as the focus of this lecture. The systematic study of lead poisoning among industrial workers which Dr. Ham- ilton performed so well, virtually single-handedly, in Illinois in 1910 led her, and those she influenced, to new careers in occupational medicine and worker health protection. Her emphasis on exposure prevention through the application of en- gineering controls to process technology gave powerful impetus to the develop- ment of the field of industrial hygiene in this country. Dr. Hamilton was personally persuasive. She had to be. As she has written: Our procedure in the Illinois survey and in the work that I carded on later for the Federal government was completely informal. We had no authority to enter any plant, we had no instructions as to which we should visit, we simply explored the state. When we found a place which seemed to belong in our field, we asked permission to enter it. Never were we refused, never did I, at least, meet with anything but courtesy in those very early days. Presentation: National Institute for Occupational Safety and Health, Cincinnati, Ohio, February 27, 1989. 0013-9351/90 $3.00 Copyright© 1990 by Academic Press, Inc. All fightsof reproduction in any formreserved.