Chronic exposure to such metals by inhalation has been linked to ailments and diseases ranging from cancer to lung and heart problems. They first tested the e-liquid in the dispenser for 15 common metals. They are a relatively new phenomenon and scientists are still learning about their long-term health effects.
Although the study was small, the authors say its findings are important and warrant evaluation by the Food and Drug Administration (FDA) due to the potential health consequences of exposure to these metals.
In the study, scientists recruited 56 daily e-cigarette smokers from vape shops and vaping conventions around Baltimore. They found low levels of metals when testing the dispenser alone, but when the liquid was heated into an aerosol, numerous samples then produced high levels of the toxins.
"These studies have also found a large variance in exposure levels among the users tested, which indicates harm can be significantly reduced with the use of quality products", Chowdhery said.
E-liquid is relatively cheap, and the vapor generally doesn't linger like smoke and bother others. Precisely how metals get from the coils into e-liquid is another mystery.More news: Twitter cracks down on bots with policy changes and mass purge
"It's important for the FDA, the e-cigarette companies and vapers themselves to know that these heating coils, as now made, seem to be leaking toxic metals, which then get into the aerosols that vapers inhale", says senior researcher Ana María Rule, assistant scientist in environmental health and engineering in Johns Hopkins University's Bloomberg School of Public Health.
From the difference, it has been concluded that the metals had come from the coils. But they nearly entirely vape now; vaping, they have said, is what allowed them to quit cigarettes.
But most worrisome were the types and quantities of metals found in the vapor that the e-cigarette-users were liberally puffing on every day.
"Metal Concentrations in e-Cigarette Liquid and Aerosol Samples: The Contribution of Metallic Coils" was written by Pablo Olmedo, Walter Goessler, Stefan Tanda, Maria Grau-Perez, Stephanie Jarmul, Angela Aherrera, Rui Chen, Markus Hilpert, Joanna E. Cohen, Ana Navas-Acien, and Ana M. Rule. Rule's team plans further studies. Among the metals present in the aerosols, lead, chromium, nickel, and manganese are the most toxic ones when inhaled.
The study appears online in the journal Environmental Health Perspectives.
"We know there are many young vapers that have never smoked", Dr. Rule said.