Lead and Public Health : Science, Risk and Regulation

The book presents a detailed assessment of the health science of lead and the human health risk assessment models for lead’s human health impacts, followed by an account of various regulatory efforts in the United States and elsewhere to eliminate or reduce human toxic exposures to lead. The science of lead as presented here covers releases of lead into the environment, lead’s movement through the environment to reach humans who are then exposed, and the spectrum of toxic effects, particularly low-level toxic effects, on the developing central nervous system of the very young child. The section on human health risk assessment deals with quantifying not only the dose-response relationships that underlie toxic responses to lead in sensitive populations but also with the likelihood of toxic responses vis-à-vis environmental lead at some level of exposure. This section includes a treatment of computer models of lead exposure, particularly those that use lead in whole blood as a key measure. Various models convert lead intake via various body compartments into measures of body lead burden. Such measures are then directly related to severity of injury.

The final section of the book deals with past and present regulatory efforts to control lead releases into the human environment. Current control efforts present a mixed picture. The most problematic issue is the continued presence of lead paint in older housing and lead in soils of urban and mining industry communities.

• Comprehensive assessment of the three major facets of the public health problem of lead: the voluminous science, the risk assessment approaches, and approaches to controlling lead as a public health problem
• Integration of the above three elements to provide a coherent whole
• Provides a single source of information that will be extremely valuable to all professionals working in areas impacted by this toxic substance

A former U.S. Surgeon General publicly called lead the chemical contaminant posing the highest environmental health threat to young children. Lead has had a multi-millennial history as a basic commodity in widespread use during the industrial and cultural development of various peoples. The continuing universal use of lead in the face of its numerous public health hazards can be traced back to various factors. Recent decades, however, have witnessed attempts at addressing lead's adverse impacts within various health risk evaluation and regulation paradigms.

This book characterizes three components of such attempts – science, risk and regulation – in the context of multiple feedback-loop interactive and integrative processes incorporating research, risk assessment, and regulatory actions at various levels. Lead research first produces a global health science database revealing effects of lead exposure from environmental contamination. These data prompt the need to quantify risks of toxic harm from lead exposures. Research and quantified risk data then reveal to policy analysts, legislators and regulators the need for regulatory controls. Legislative and regulatory actions reveal remaining needs for more research and risk evaluations. Support for further research then occurs, repeating the feedback-loop interactive cycle.

Lead's environmental and toxicological behavior makes these interactive relationships challenging to address and implement. It is a multimedia pollutant. It produces actual, diagnosable disease and disease risks depicted probabilistically. Lead’s toxicological potency in humans is expressed empirically without threshold. Pervasive contamination by lead thwarts simple, inexpensive regulatory remedies. This book serves as a guide to these challenges and their solutions.