Public health experts are deeply divided on the perils and benefits of e-cigarettes. Some say they offer the first satisfying alternative to smoking in generations and could greatly reduce health risks, while others contend they could become a gateway to traditional cigarette smoking for young people.

The report surveyed nine major producers, though only eight responded: Altria, R. J. Reynolds Vapor Company, NJOY, Eonsmoke, Logic, VMR, Lorillard and Green Smoke. Six of them said they had sponsored events, and eight said they had given away free samples. In all, 348 events featured free giveaways and sponsorship in 2012 and 2013, “many of which appeared geared toward youth,” the report said.

A spokesman for the Smoke Free Alternatives Trade Association, the e-cigarette industry’s trade group, said, “We encourage responsible marketing directed to those over the age of 18,” and added it “does not support, and our industry does not use, youth-oriented product marketing.”

The report found that Lorillard represented the largest portion of the giveaways and sponsorships in 2012 and 2013, providing free e-cigarette samples or sponsorship at 227 of the events, which included music festivals, parties and motor sports competitions. It also sponsored Freedom Project, a national tour by a number of bands. This year, tobacco control advocates criticized ads for the company’s Blu brand e-cigarettes that ran in Sports Illustrated magazine and featured women in bikinis, calling them an attempt to appeal to teenage boys.

Robert Bannon, a spokesman for Lorillard, said in a statement that the company does not advertise to youths. “We have taken many steps to limit exposure of individuals under age 18 to our advertising and promotional activities and to prevent them from purchasing our electronic cigarette products,” he said.