The Health Effects of Low Level Exposure to Lead

Abstract

Eight years ago, the problem of low level lead exposure in children was reviewed in the Annual Review of Public Health (65). (The term "low level" refers to exposure that is below those at which clinical signs of lead poisoning are apparent. ) Since that time, knowledge about lead's health effects , bio­ chemical toxicology, and sources and routes to people has grown ex­ ponentially. Real progress in lowering environmental levels of lead has been achieved, notably through the virtual ban on leaded gasoline . In some sectors, particularly housing, efforts to abate lead have failed completely. But, despite increased recognition of the widespread distribution of lead, islands of igno­ rance about its effects at low dose persist. Many modem pediatric textbooks contain discussions of the diagnosis and treatment of frank lead poisoning, but do not mention effects of lead at lesser dose. In this review , we examine some of the newer biomedical and epidemiolog­ ical information about lead at low dose and evaluate the recent studies . We then suggest some policy actions to redress the imbalance between the broad knowledge of lead's dangers and the limited steps to eliminate them.