Nutrition and lead: strategies for public health.

Over the past two decades, blood lead levels among U.S. children have been reduced by approximately 80%. This decline reflects both primary interventions (removal of lead solder from food beverage cans and virtual elimination of lead additives from gasoline) and secondary prevention strategies (public health programs and nutritional intervention). Nonetheless, pediatric lead poisoning (i.e., blood lead concentrations . 10 pg/dl) continues to occur in 8.9% of 1to 5-year-old children. Currently, blood lead concentrations exceed the U.S. Centers for Disease Control's targeted value (10 jig/dl), most often among minority and low-income populations. These same subpopulations are at greatest risk of marginal nutrition status (especially for iron and calcium), which increases their susceptibility to lead toxicity. Adverse child feeding practices (e.g., irregular temporal patterns of food intake) are also of concern among the subpopulations at highest risk to excessive lead exposure. This paper describes nutrition interventions and public health strategies aimed at minimizing the transfer of lead from external or environmental dose to internal dose as reflected by blood lead concentration. Public health strategies have evolved over the past half-century to assess the risks and benefits of trace quantities of chemicals. Trace quantities typically describe substances present in sources at parts per million concentrations (ppm) or less. Virtually all of these chemicals can produce adverse effects on human health if the con-