Research to Reality: Applying Findings to Practice

In 1991, the Centers for Disease Control and Prevention (CDC) defined blood lead levels above 10 g/ dL as needing to prompt public health action. However, research since that time indicates adverse effects on children’s physical, mental, and cognitive development with blood lead levels (BLL) less than 10 g/ dL. In 2005, the Advisory Committee on Childhood Lead Poisoning Prevention determined an inverse relationship between BLL and cognitive function. The studies included in this 2007 report address BLLs below the 10 g/dL threshold where this inverse relationship persists despite the lower BLL. Since 1976 there have been substantial decreases in childhood exposure to lead mainly due to regulatory policies. However, imprecision in specimen collection and analytic techniques reveals BLL variations due to an allowable error range. For instance, ‘‘an actual value of blood lead at 7 g/dL could be reported as being any value ranging from 3 g/dL to 11 g/dL and still remain within the allowable error limit’’ as established by federal regulations (p. 3). Although a rapid increase in BLL occurs after acute exposure followed by a gradual decrease in body stores, 70% of lead is stored in bone compartments that can be present for decades. Therefore, BLL levels may not indicate the pattern of exposure to lead, depending on the time of testing. Exposure to lead occurs through a variety of mechanisms. ‘‘The major sources of lead exposure among U.S. children are lead contaminated dust, deteriorated lead-based paint, and lead-contaminated soil’’ (p. 4), although water can be a problem if additives in the disinfection processes are changed. Other sources of