Amid a multitude of reports about severe lung illnesses associated with vaping, federal health agencies have urged everyone to avoid electronic cigarettes and cautioned that pointing blame at any one brand, chemical or substance in isolation is premature. But even while federal officials say the investigation is inconclusive for now, Americans are drawing their own conclusions, largely coding the outbreak as a crisis of conventional e-cigarettes like those made by Juul Labs Inc.

While 34 percent of adults believe the lung disease deaths are related to using marijuana and THC-containing vapes, 58 percent say nicotine e-cigarettes such as Juul are to blame. That’s from a new Morning Consult survey of 2,200 U.S. adults, conducted Sept. 12-14, suggesting Americans grasping for answers are attributing the outbreak to the vaping products they know better — even as experts say most affected patients were using vapes to smoke THC, the psychoactive substance in cannabis.