For a number of smokers, e-cigarettes are a saving grace — a way to stub the butt without going cold turkey. While vaping devices are a healthier alternative to traditional cigarettes, they still come with their own health risks.

A new study conducted by the Johns Hopkins Bloomberg School of Public Health identified that some e-cigarettes released toxic substances into the vapors being inhaled by users. After examining devices used by 56 daily vapers, scientists discovered that a number of them generated aerosols that contained unsafe amounts of lead, chromium, manganese and zinc and nickel.

Published in Environmental Health Perspectives, the research was based on tests conducted on the e-liquid from the refilling dispenser (before contact with the device and the heating coil), e-liquid in the device itself (in contact with the heating coil), and the generated aerosol (inhaled by the user).

Previous studies on metals in e-cigarettes were focused on cigalikes, early devices that contained a disposable cartomizer with a coil and preloaded e-liquid. Newer versions however, allow daily users opt for reusable modified devices that allow them to refill the e-liquid from a dispenser. They offer different levels of voltage and coil composition and can be manipulated by the user based on his requirements. Scientists specifically choose to study samples from e-cigarette consumers rather than purchasing e-cigarettes from a store or company in order to assess typically used devices.

Typically, e-liquid in the dispensers has an insignificant amount of metal in it. However, once exposed to the heating coil, the concentration increased noticeably. For example, the median lead concentration in the aerosols was more than 25 times greater than the median level in the refill dispensers. Close to 50% of the cases showed lead concentrations higher than health-based limits defined by the Environmental Protection Agency.

“These were median levels only. The actual levels of these metals varied greatly from sample to sample, and often were much higher than safe limits,” said the study’s senior author Ana María Rule, an assistant scientist in the Bloomberg School’s Department of Environmental Health and Engineering.

Regular inhalation of these toxic metals is known to cause lung, liver, immune, heart and brain damage and has been linked to cancer.
While heating coils typically contain nickel and chromium, Rule said the team was still unable to identify how the metals were transferred into the liquid. “We don’t know yet whether metals are chemically leaching from the coil or vaporizing when it’s heated,” she added.

The investigation also revealed that metal concentrations in the vapors were higher for e-cigarettes in which the coils were changed more often. This suggest that fresher coils release a higher amount of metals.

“It’s important for the Food and Drug Administration (FDA), the e-cigarette companies and vapers themselves to know that these heating coils, as currently made, seem to be leaking toxic metals—which then get into the aerosols that vapers inhale,” warned Rule.
The release of the Bloomberg study happened to coincide with a statement by the American Cancer Society supporting the use of e-cigarettes for people considering quitting traditional cigarettes.

“Many smokers choose to quit smoking without the assistance of a clinician and some opt to use e-cigarettes to accomplish this goal,” the organization mentioned. “The ACS recommends that clinicians support all attempts to quit the use of combustible tobacco and work with smokers to eventually stop using any tobacco product, including e-cigarettes. Switching to the exclusive use of e-cigarettes is preferable to continuing to smoke combustible products.”

In 2015, an expert independent evidence review published by Public Health England (PHE) concluded that e-cigarettes are 95% less harmful that tobacco burning varieties and had the potential of helping people quit smoking.

However, considering the nascent stage of research into these electronic devices, most organizations continue to stress the need for more research.

“The ACS encourages the FDA to regulate all tobacco products, including e-cigarettes, to the full extent of its authority, and to determine the absolute and relative harms of each product. The FDA should assess whether e-cigarettes help to reduce tobacco-related morbidity and mortality, and the impact of marketing of e-cigarettes on consumer perceptions and behavior,” the ACS added in its statement.