Minimal amounts of the metals were identified in the e-liquids, but their volumes significantly increased after the liquids were exposed to a device's heating coils.
"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. While vaping devices are a healthier alternative to traditional cigarettes, they still come with their own health risks.
The scientists in the most recent study say the median level of lead found in their sample was higher than the Environmental Protection Agency's safety standard, and that levels of other metals such as nickel, chromium and manganese "approached or exceeded safe limits". How the arsenic got into these e-liquids is yet another mystery-and another potential focus for regulators.
Although not being part of an e-cigarette coil, the scientists found that the unsafe chemical arsenic was also being produced by the heating process.
For the new study, Rule and her colleagues recruited 56 daily e-cigarette users from vaping conventions and e-cigarette shops around Baltimore during the fall of 2015.
They tested whether the e-liquids in the devices' refilling tanks and the aerosol produced contain any toxic metals.
Significant amounts of lead and other toxic metals leak from some heating coils in e-cigarettes and contaminate aerosols that the user inhales, a new study suggests.
"Several shortcomings were found in a similar study conducted by the same institute past year, including overestimating normal levels of exposure, not factoring in exposure to metals from daily activities, small sample size of products tested", Samrat Chowdhery, Director, Assocation of Vapers India (AVI), said in a statement. Nearly 50 percent of aerosol samples had lead concentrations higher than health-based limits defined by the Environmental Protection Agency.
The researchers called on the US Food and Drugs Administration (FDA) to regulate the devices.
"These were median levels only". They went on to show that the metals can then end up in the aerosols, i.e. the vapor, from the heated e-liquid.
According to a study conducted by at Johns Hopkins Bloomberg School of Public Health, significant amounts of toxic metals, including lead, leaking from e-cigarette heating coils and are present in the aerosols inhaled by users. More research must be done to determine possible health affects.