PORTLAND, Ore., March 19 New cigarettes extolling reduced toxic exposures may be promising too much, says a U.S. study.The predicted risks of lung cancer from "potentially reduced-exposure product" cigarettes is not meaningfully lower than for the conventional cigarettes most smokers puff every day, according to the study in the journal Cancer Epidemiology Biomarkers & Prevention. Even if known toxins such as formaldehyde, arsenic and cadmium are removed from cigarette smoke by the new PREP designs, tobacco companies could not be sure the cancer risks had been lowered in any meaningful way, Dr. James F. Pankow of Oregon Health & Science University in Portland said in a statement.Such promises are "speculative and unverified," Pankow added. "Dr. Pankow's study shows simply lowering the levels of a few known harmful compounds from tobacco smoke may not significantly reduce the risks of smoking," Pamela Clark, a scientist at in Baltimore, said in a statement. Copyright 2007 by UPI