Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AQCD/Addendum and 1990 Supplement, with the main focus being on pertinent new
information useful in evaluating health and environmental effects of ambient air lead exposures.
This includes discussion in this document of information regarding: the nature, sources,
distribution, measurement, and concentrations of lead in the environment; multimedia lead
exposure (via air, food, water, etc.) and biokinetic modeling of contributions of such exposures
to concentrations of lead in brain, kidney, and other tissues (e.g., blood and bone concentrations,
as key indices of lead exposure).; characterization of lead health effects and associated exposureresponse
relationships; and delineation of environmental (ecological) effects of lead. This final
version of the revised Lead AQCD mainly assesses pertinent literature published or accepted for
publication through December 2005.
The First External Review Draft (dated December 2005) of the revised Lead AQCD
underwent public comment and was reviewed by the Clean Air Scientific Advisory Committee
(CASAC) at a public meeting held in Durham, NC on February 28-March 1, 2006. The public
comments and CASAC recommendations received were taken into account in making
appropriate revisions and incorporating them into a Second External Review Draft (dated May,
2006) which was released for further public comment and CASAC review at a public meeting
held June 28-29, 2006. In addition, still further revised drafts of the Integrative Synthesis
chapter and the Executive Summary were then issued and discussed during an August 15, 2006
CASAC teleconference call. Public comments and CASAC advice received on these latter
materials, as well as Second External Review Draft materials, were taken into account in making
and incorporating further revisions into this final version of this Lead AQCD, which is being
issued to meet an October 1, 2006 court-ordered deadline. Evaluations contained in the present
document provide inputs to an associated Lead Staff Paper prepared by EPA’s Office of Air
Quality Planning and Standards (OAQPS), which poses options for consideration by the EPA
Administrator with regard to proposal and, ultimately, promulgation of decisions on potential
retention or revision, as appropriate, of the current Pb NAAQS.
Preparation of this document has been coordinated by staff of EPA’s National Center for
Environmental Assessment in Research Triangle Park (NCEA-RTP). NCEA-RTP scientific
staff, together with experts from academia, contributed to writing of document chapters. Earlier
drafts of document materials were reviewed by scientists from other EPA units and by non-EPA
experts in several public peer consultation workshops held by EPA in July/August 2005.
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