The Bureau of Mines evaluated the technology and capital investment and annual operating costs of emission control for further reductions of lead in ambient air at the Glover, Herculaneum, and Buick Smelter-Refineries in Missouri and the East Helena, Montana, smelter. This study seeks to analyze the technology available to the domestic primary lead industry for attempting to further reduce lead emissions below 1985 levels. Through enclosure of concentrate unloading and handling areas and all lead processing buildings, followed by venting these enclosures to the atmosphere through baghouses and the application of appropriate local controls, lead inventories can theoretically be reduced by 2,424 pounds per day from 1985 levels. Using conventional technology, aggregated additional capital costs of $250,014,000 and annual operating costs of $18,507,800 are estimated for the four operations, resulting in a total cost of $0.063 Per pound of refined lead. Continuous drossing techniques would assist in meeting osha standards in process areas. Continuous drossing would increase capital and operating costs to $258,344,800 and $16,104,700, respectively, for a total cost of $0.062 Per pound of refined lead. The open market price for refined lead for the first quarter of 1986 was $0.184 Per pound.