Correspondence: comments on "recent developments in low-level lead exposure and intellectual impairment in children"

We commend Koller et al. (2004) for their thoughtful and detailed review of recent research on childhood lead exposure and intellectual development, and we take this opportunity to clarify and respond to several of their questions regarding our study of children with blood lead concentrations 10 microg/dL) (Canfield et al. 2003).