National Ambient Air Quality Standards for Lead

Based on its review of the air quality criteria and national ambient air quality standards (NAAQS) for lead (Pb), EPA proposes to make revisions to the primary and secondary NAAQS for Pb to provide requisite protection of public health and welfare, respectively. EPA proposes to revise various elements of the primary standard to provide increased protection for children and other at-risk populations against an array of adverse health effects, most notably including neurological effects, particularly neurocognitive and neurobehavioral effects, in children. With regard to the level and indicator of the standard, EPA proposes to revise the level to within the range of 0.10 to 0.30 [mu]g/ m\3\ in conjunction with retaining the current indicator of Pb in total suspended particles (Pb-TSP) but with allowance for the use of Pb- PM10 data, and solicits comment on alternative levels up to 0.50 [mu]g/m\3\ and down below 0.10 [mu]g/m\3\. With regard to the averaging time and form of the standard, EPA proposes two options: To retain the current averaging time of a calendar quarter and the current not-to-be-exceeded form, revised to apply across a 3-year span; and to revise the averaging time to a calendar month and the form to the second-highest monthly average across a 3-year span. EPA also solicits comment on revising the indicator to Pb-PM10 and on the same broad range of levels on which EPA is soliciting comment for the Pb-TSP indicator (up to 0.50 [mu]g/m\3\). EPA also invites comment on when, if ever, it would be appropriate to set a NAAQS for Pb at a level of zero. EPA proposes to make the secondary standard identical in all respects to the proposed primary standard.

Agency Contact: For further information in general or specifically with regard to sections I through III or VII, contact Dr. Deirdre Murphy, Health and Environmental Impacts Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Mail code C504-06, Research Triangle Park, NC 27711; telephone: 919-541-0729; fax: 919-541-0237; e-mail: Murphy.deirdre@epa.gov. With regard to Section IV, contact Mr. Mark Schmidt, Air Quality Analysis Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Mail code C304-04, Research Triangle Park, NC 27711; telephone: 919-541-2416; fax: 919-541-1903; e-mail: Schmidt.mark@epa.gov. With regard to Section V, contact Mr. Kevin Cavender, Air Quality Analysis Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Mail code C304-06, Research Triangle Park, NC 27711; telephone: 919-541-2364; fax: 919- 541-1903; e-mail: Cavender.kevin@epa.gov. With regard to Section VI, contact Mr. Larry Wallace, Ph.D., Air Quality Policy Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Mail code C539-01, Research Triangle Park, NC 27711; telephone: 919-541-0906; fax: 919-541-0824; e-mail: Wallace.larry@epa.gov.