(Photo : Image by rolandmey from Pixabay)

Researchers from Harvard T.H. Chan School of Public Health carried out a new study published online in Environmental Health Perspectives discovered that the popular electronic cigarette, e-cigarette, products sold all over the U.S. were contaminated with bacterial and fungal toxins.

The research examined 75 popular e-cigarette products, e-liquids, refillable material and cartridges, single use, and they found out that 27 percent contained traces of endotoxin, a microbial agent found on Gram-negative bacteria, and that 81 percent contained traces of glucan which is located in the cell walls of most fungi. Contact with these microbial toxins has been connected with myriads health problems in humans, including asthma, reduced lung function, and inflammation.

Elkan Blout Professor of Environmental Genetics and senior author of the research, David Christiani said that airborne Gram-negative bacterial endotoxin and fungal-derived glucans had been shown to cause acute and chronic respiratory effects in occupational and environmental settings. And for them to find these toxins in e-cigarette products adds to the growing concerns about the potential for adverse respiratory effects in users.

There has been an increase in the use of e-cigarettes in recent years, particularly among high school and middle school students. In 2018, it was estimated that more than three million high school students used e-cigarettes, up from 220,000 in 2011. Harvard Chan School made the previous study which showed that chemicals linked with severe respiratory disease are found in favorite e-cigarette flavors. Furthermore, after several investigations conducted over many years, it has been demonstrated that chronic lung impairment in populations exposed to airborne biological contaminants. Even with this, the author of this study claimed that no research exists on the potential contamination of e-cigarettes with microbes or microbial toxins.

After their investigations, the findings of the researchers showed that 17 of 75 products (23 percent) contained detectable concentrations of endotoxin and that 61 of 75 products (81 percent) contained detectable concentrations of glucan. Additional analysis showed that cartridge samples had 3.2 times higher concentrations of glucan than the e-liquid samples.

Glucan concentrations were also significantly higher in tobacco- and menthol-flavored products than in fruit-flavored products which indicated that raw materials used in the product of flavors might be a source of microbial contamination.

The team pointed out that the contamination of the products could have occurred at any point during the product of the ingredients or the finished e-cigarette product. The researchers hypothesized that cotton wicks used in e-cigarette cartridges might be one potential source of contamination since both endotoxin and glucan are known contaminants of cotton fibers.

The lead author of the study and a research fellow, Mi-Sun Lee said that in addition to inhaling harmful chemicals, e-cigarette users could also be exposed to biological contaminants like endotoxin and glucan. He added that these new findings should be considered when developing regulatory policies for e-cigarettes.