By JIM SALTERHERCULANEUM, Mo. (AP) a¿¿ From the day its founder arrived here, this Mississippi River town has been tied inseparably to lead, the heavy, dull-gray metal that has been mined in southern Missouri for more than two centuries. As home to the nation's only primary lead smelter, Herculaneum processes raw ore into metal to make car batteries, X-ray shields and many other products. But the end of that long tradition is in sight for the small town 25 miles south of St. Louis that began smelting when this land was still owned by Spain. The company that runs the smelter, Doe Run Co., has decided to cease most operations at the end of the year, citing rising regulatory costs. Lead has been both kind and cruel to Herculaneum, giving it an identity and ready jobs but also creating environmental and health concerns so worrisome that the federal government designated it a Superfund site and ordered tons of contaminated dirt to be dug up and removed. Many of the town's children were found to have dangerously high lead levels in their blood. Leslie and Jack Warden won't miss the smelter. For 16 years, the couple lived less than three blocks away, literally in the shadow of the plant's 550-foot smokestack. They raised their son there. Now 29, Eric Warden still suffers from developmental delays a¿¿ a common effect of lead poisoning. "I guess living there, you became pretty complacent about the dust, the fog, the smells," Leslie Warden said. "It clung to the house. It was almost like a sticky dust." The Wardens were leaders of the effort to convince the Environmental Protection Agency to assess Herculaneum's air quality in 2001. That testing was the impetus behind the move to clean up lead in the town known by locals as "Herky."