Lead Air Pollution

Table of Historical Lead (Pb) National Ambient Air Quality Standards (NAAQS)

History of the NAAQS for Pb
Final Rule/Decision Primary/Secondary Indicator1 Averaging Time Level2 Form

43 FR 46246
Oct 5, 1978
Primary and Secondary Pb-TSP Calendar Quarter 1.5 µg/m3 Not to be exceeded
1991 Agency released multimedia "Strategy for Reducing Lead Exposures"

73 FR 66964
Nov 12, 2008
Primary and Secondary Pb-TSP 3-month period 0.15 µg/m3 Not to be exceeded

81 FR 71906
Oct 18, 2016
Primary and secondary standards retained, without revision.

1. Pb-TSP = Lead in total suspended particles

2. Units of measure are micrograms per cubic meter of air (µg/m3).