An overview of the epidemiology of blood pressure is presented as background for the International Symposium of Blood Lead-Blood Pressure Relationships. The correlates of blood pressure distributions in populations are varied and numerous. They have to be considered as either potential confounders or modifiers of any blood pressure-blood lead relationship detected. The relation of blood pressure to cardiovascular morbidity and mortality emphasizes the importance of detecting and elucidating any possible causal association of blood lead with blood pressure at low levels. The task of this symposium is of public health importance, as relatively minor changes in the distribution and mean levels of blood pressure in populations are associated with major morbidity and mortality consequences
