San Francisco city supervisors will consider a ban Tuesday on the sale of electronic cigarettes in that city until the Food and Drug Administration completes its review of the devices. “Personally, I think anybody who sees the uptake of e-cigarettes amongst youth should be concerned about long-term consequences … because we just don’t know what the health risks are,” says Dr. Daniel Conklin, a University of Louisville Medical School professor and researcher studying the effects of vaping on the cardiovascular system.