Amid continuing concerns about the safety of e-cigarettes, new research suggests that vaping may expose users to high levels of heavy metals, which can be extremely toxic to the body. 

In a study published last week in the medical journal Environmental Health Perspectives, Johns Hopkins researchers found high levels of chromium, lead, manganese, nickel and zinc in the e-cigarette liquid. Unhealthy levels of arsenic were also found in a some of the tests.

Researchers sampled 56 e-cigarette devices from daily e-cigarette users and obtained samples from the refilling dispenser, aerosol, and remaining e-liquid in the tank. Aerosol liquid was also collected from deposited droplets on conical pipette tips.

The liquid and aerosol was analyzed for 15 metals, including aluminum, antimony, arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, titanium, tungsten, uranium and zinc.

The study suggests that the metal concentrations were higher in the tank and aerosol compared to the refill dispenser. Researchers indicate that suggests the heating coil is the source of the metal.

Tiny metal coils are used to heat e-liquid in e-cigarettes. Researchers think those coils may contaminate the vapor with lead, chromium, manganese, and nickel.

For example, measurements of nickel reached 68 mg/kg and 233 mg/kg in the tank and aerosol, but were 0.5 mg/kg in the refill dispenser. Similarly, levels of zinc reached 515 and 426 mg/kg, while reaching 13 mg/kg in the dispenser. Zinc, which is safe to humans when ingested can be rather toxic when inhaled. It is known to caused metal fume fever, which can cause fever, chills, pneumonia, chest pain, and nausea.

Prior studies have linked inhalation of metals to cancers of the lung, liver, heart and to brain damage. Chronic exposure can also affect the immune system and increase the risk for other types of cancer.

Nearly all of the metals tested for were detectable in the majority of the samples. Arsenic was detectable in about 10% of the samples.

Researchers noted that metal concentrations exceeded current health safety limits in 50% or more of the samples. This was especially the case for chromium, manganese, nickel and lead.

Toxic levels were measured higher coming from e-cigarettes which had the metal coils changed more frequently. New coils seemed to produce more toxins than older coils.

However, the presence of some metals was detected in some of the liquids even before contact with the coil. Researchers speculate that other factors could play a role, such as the voltage used to heat the coil.

The findings come as more studies indicate the potentially harmful effects the devices pose to users from the release of toxic cancer-causing chemicals during aerosolization. Research published last year even linked vaping to increased risk of heart disease.

Tags: Cancer, Electronic Cigarettes, Lead Exposure, Liquid Nicotine, Smokers, Toxicity