Lead, chrome and arsenic in the vapor of e-cigarettes
Significant amounts of toxic metals, including lead, appear to emerge from some e-cigarette heating coils and are contained in the aerosols inhaled by users. These metals consumed by users can harm the lungs, liver, cardiovascular system and brain. They have also been linked to the development of cancer.
In their current study, the scientists at the Johns Hopkins Bloomberg School of Public Health found that so-called e-cigarettes often produce a significant number of aerosols with potentially unsafe levels of lead, chromium, manganese and nickel. The doctors published the results of their study in the English-language journal "Environmental Health Perspectives".
Heating coil origin of the metals?
In a sample of the e-cigarette devices from a total of 56 users, the experts found that the heating coils of the devices released aerosols with toxic metals, which the users inhaled. Chronic inhalation of these metals damages a number of organs, such as the brain and heart, and could contribute to the development of cancer.
Users must be informed about risks
"It is important for the FDA (Food and Drug Administration), the e-cigarette companies and the users themselves to know that the heating coils as they are currently being produced release toxic metals, which are then released into the aerosols, which Inhale users, ”explains study author Dr. Ana María Rule from the Department of Environmental Health and Engineering at the Johns Hopkins Bloomberg School of Public Health.
How do e-cigarettes work?
E-cigarettes typically use battery-powered electrical current that flows through a metal coil to heat so-called liquids, which creates an aerosol. The mixture contains the vaporized liquid and tiny droplets of liquid. This aerosol is inhaled like cigarette smoke. The process is called evaporation. The use of e-cigarettes is particularly popular with teenagers, young adults and former smokers.
Why are e-cigarettes so popular?
Vaping is so popular because it creates the kick of nicotine and provides the feeling of smoking, but supposedly without the extreme health risks. However, there is growing evidence that vaping is not entirely safe. For example, recent studies have already shown that the liquids in e-cigarettes contain flavors and other chemicals that damage cells in standard toxicological tests.
56 e-cigarettes from daily users were examined
In their study, the physicians examined the devices of 56 daily e-cigarette users in autumn 2015. The devices were brought into the laboratory of the researchers at the Johns Hopkins Bloomberg School of Public Health by the participants. There, the scientists tested the presence of 15 metals in the so-called e-liquids and in the aerosols generated.
Metals probably came from the heating coils
Consistent with previous studies, they found minimal amounts of metals in the liquids within the so-called refill dispensers, but much larger amounts of some metals in the liquids that were exposed to the heating coils in e-cigarettes. The difference indicated that the metals almost certainly came from the heating coils. Most importantly, the scientists were able to show that the metal contamination is transferred to the aerosols that are generated by heating the liquids.
What metals were in the steam?
Of the metals that are significantly present in the aerosols, lead, chromium, nickel and manganese were the most worrying substances, as all are toxic when inhaled, the researchers explain. The median lead concentration in the aerosols was, for example, about 15 µg / kg or more. This was 25 times more than the median in the refill dispensers. Almost 50 percent of the aerosol samples contained lead concentrations that were higher than the health limits defined by the Environmental Protection Agency. Similarly, the median aerosol concentrations of nickel, chromium and manganese reached or exceeded the safety limits.
Concentrations were often far above the safe limit values
These were just averages, says Dr. Rule. "The actual concentrations of these metals varied widely from sample to sample and were often well above the safe limits," added the expert in a press release from the Johns Hopkins Bloomberg School of Public Health.
How do metals get into the liquid from the heating coil?
E-cigarette coils are typically made of nickel, chrome, and some other elements, making them the most obvious sources of metal contamination, although the source of the lead remains a mystery. How metals get from the coil into the surrounding liquid is another mystery. "We don't yet know whether metals will emerge chemically from the coil or evaporate when heated," says Dr. Rule on. In a previous study of 56 users, the levels of nickel and chromium in their urine and saliva were comparable to those in aerosol, which confirms that e-cigarette users are exposed to these metals.
Arsenic can also be contained in the steam
The researchers also detected significant amounts of arsenic - a metal-like element that can be very toxic - in refill liquids and in the corresponding e-liquid in the tanks of the devices and in the aerosol samples in 10 of the 56 devices examined. Further studies must now be carried out to determine the actual health effects. (as)