The recently published study in Environmental Health Perspectives investigated the possible contribution of heating coil to metal exposure in e-cigarette users wherein scientists examined 56 e-cigarette sample devices obtained from daily e-cigarette users to identify the transfer of metals from the heating coil to the e-liquid and the generated aerosol. But in over half of the e-cigs, the liquid inside the dispenser and the aerosol contained significant levels of chromium, nickel, and lead. Study authors pointed out that chronic inhalation of these metals has been linked to lung, liver, immune, cardiovascular and brain damage, and even cancers.
The amount of lead found in the aerosols produced by the devices was, in some cases, more than 25 times greater than in the refill dispensers.
The researchers called on the US Food and Drugs Administration (FDA) to regulate the devices.
E-cigarettes have increasingly been seen as a possible savior for many who struggle to kick their cigarette addiction, as the vapor is deemed much less risky than the tar caused by regular smoking.
The research was carried out at John Hopkins University, where the researchers conducted a study in which participated 56 users of electronic cigarettes. The researchers then asked to test the levels of toxic metals in the users' e-liquid before it had been put into the device, the e-liquid in the storage tank of the device, and in the vapor that came out of the device. Four metals were excluded because of low levels: arsenic, titanium, uranium and tungsten.
'These were median levels only, ' says senior study author Dr Ana María Rule.
The question is whether exposure to those toxic metals, at the level found in normal, everyday e-cigarette use, is risky. They found highly toxic arsenic in 10 samples, according to USA Today. Nickel, chromium and manganese approached or exceeded safe limits, the researchers report.
E-cigarette heating coils are normally made of nickel, chromium and a few other elements.
"We don't know yet whether metals are chemically leaching from the coil or vaporizing when it's heated", Rule said.
Test results also showed that aerosol metal concentrations were highest for e-cigarettes with more frequently changed coils.
The FDA does not now regulate e-cigarettes but has the authority to do so, the study authors noted. The heat generates aerosol, which is a mix of vapors and tiny droplets formed from the e-liquid. Rule's team plans further studies. "We've established with this study that there are exposures to these metals, which is the first step, but we need also to determine the actual health effects", she says. An earlier study had indicated that the flavorings in e-cigarettes could damage heart muscle.