About 75 people signed up for the free conference, which included workshops aimed at educating participants on the problem of underage smoking and ways to stop it, said Nell F. Stewart, coordinator of the Washington County Health Department's "Stop Smoking For Life" program.
Using a slide presentation he said showed his Richmond, Va., lab, notebook excerpts and internal communications, DeNoble talked about the 1980 to 1984 stretch when he was looking for a substitute for nicotine without its harmful cardiovascular effects.
DeNoble said that his rats, trained to press levers to self-administer nicotine on demand, would take high doses - equal to 90 full-strength cigarettes - each day.
He said he found that when lower doses - replicating light cigarettes - were offered, the rats responded by increasing frequency.
During a later test, in which a minute amount of nicotine was sent directly into the brain, the rats became prostrate after initial injections but eventually stopped reacting, he said.
That led DeNoble to conclude that the nicotine had altered the rats' brain functions, which he said would classify it as a drug under the FDA's definition.
"It's clearly a drug. There's no doubt about it, and the industry has known for years that people smoke for nicotine," said DeNoble, 47, who claims the tobacco giant allowed only a watered-down version of his conclusions to be released.
Phillip Morris lawyer Michael York, contacted by telephone, said the company never silenced DeNoble.
York said that DeNoble and other researchers have never found a commercially usable substitute for nicotine, which occurs naturally in tobacco.
In reporting his research conclusions, DeNoble told both his Phillip Morris superiors and a congressional subcommittee that his studies did not show that nicotine was addictive, York said.
DeNoble said he plans to use his inside knowledge of the tobacco industry as director of the American Lung Association's tobacco education project in Delaware, a position he'll take over April 1.
The health department and the Washington County Tobacco Use Prevention Coalition co-sponsored the first-time event, funding through a grant from the Maryland Health Department's Smoking Prevention Program, Stewart said.