Microbial Contaminants Found in E-Cigarettes.

Popular electronic cigarette products sold in the U.S. are contaminated with bacterial and fungal toxins, according to research from the Harvard University School of Public Health published in Environmental Health Perspectives.

The study, which examined 75 popular e-cigarette products--cartridges (single use) and e-liquids (refillable material)--found that 23% contained traces of endotoxin, a microbial agent found on Gram-negative bacteria, and 81% traces of glucan, which is found in the cell walls of most fungi. Exposure to these microbial toxins has been associated with myriad health problems in humans, including asthma, reduced lung function, and inflammation.

"Airborne Gram-negative bacterial endotoxin and fungal-derived glucans have been shown to cause acute and chronic respiratory effects in occupational and environmental settings," says senior author David Christiani, professor of environmental genetics. "Finding these toxins...