This is the finding of a new study by researchers at Johns Hopkins Bloomberg School of Public Health, published yesterday in Environmental Health Perspectives.
While the study is small-evaluating devices in a random sample of 56 users-it revealed that a significant number of the devices produced aerosols with potentially dangerous levels of lead, as well as other important metals such as chromium, manganese and nickel. Chronic exposure to such metals by inhalation has been linked to wide ranging effects--including cancer--on multiple organ systems including the lungs, brain, heart, liver, as well as the immune system.
Even though the FDA has the ability to regulate e-cigarettes, there has been no firm indication if, or how, it may choose to address findings by this and previous studies regarding the toxicity of the contents of the vapor. But it's fair to say that the FDA will likely have a say by issuing future rulings on this important matter.
"It's important for the 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," said Ana Maria Rule, PhD, MHS, the senior author of the study in a press release.
In a typical e-cigarette, an electric current produced by a battery passes through a metal coil to heat nicotine-based e-liquids to create an aerosol. What's clear is that vaping has not only emerged as an alternative among former smokers, but also teens and even those in middle school. In fact, according to a 2017 survey by the National Institute on Drug Abuse (NIDA), nearly 15% of 8th, 10th and 12th grade students in public and private schools has used e-cigarettes in the past month.
Vaping is considered a form of "harm-reduction" because it reduces the risk of cancer and heart disease associated with combustion of tobacco products, but it still delivers the "hit" of nicotine along with its characteristic "look and feel". Yet, there are studies which have found that vaping does carry medical risks. In fact, there are studies which have noted that animals (mice) and animal cells grown in standard culture in laboratory settings may both be harmed by e-cigarette liquids. Rule has previously published data last year which demonstrated elevated levels of toxic metals in e-liquids exposed to the e-cigarette heating coil.
Rule's current study selected 56 daily e-cigarette users recruited from vaping conventions and e-cigarette stores in Baltimore, Maryland during late 2015. The research team analyzed their devices for 15 metals in their refilling dispensers, the e-cigarette reservoirs, as well as in the aerosols generated from their devices.
The researchers found small amounts of metals in the e-liquids inside refilling dispensers, just as in previous studies. However, there were significantly greater amounts of some metals in the e-liquids that had been exposed to the heating coils within e-cigarette reservoirs. The metals accounting for the difference had, most likely, originated from the coils. But another key finding of the researchers was that the higher metal concentrations were also evident in the aerosols that were generated by heating the e-liquids.
The levels of lead, chromium, nickel and manganese were noted to be elevated, and certainly toxic when inhaled. The median lead concentration in the aerosols was close to 15 ug/kg--25 times greater than the median level in the refill dispensers.
And nearly half of all aerosol samples had lead concentrations higher than health limits set by the Environmental Protection Agency (EPA). The median aerosol concentrations of nickel, chromium and manganese were also at risk, or exceeded safe levels set by the EPA.
"These were median levels only," said Rule. "The actual levels of these metals varied greatly from sample to sample, and often were much higher than safe limits."
The e-cigarette heating coils are generally composed of nickel, chromium and other metals, indicating them to be the clear source of metal contamination. But the source of the lead is unclear, according to Rule. "We don't know yet whether metals are chemically leaching from the coil or vaporizing when it's heated," offered Rule.
One of the key findings to emerge from this study is that aerosol metal concentrations were typically higher for e-cigarettes with coils that were changed more often, suggesting that newer coils may shed or leach metals more easily.
What's even more concerning is that the investigators also found significant levels of the toxic chemical arsenic not only in in e-liquid refills, but also in reservoir e-liquid and aerosol samples from 10 of the 56 vapers studied.
But it's the long-term effects of vaping and metal exposures which must be systematically studied. "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 concluded.
"This important study lends confirmation to the growing concern of clinicians, healthcare officials, and concerned citizens that current vaping instruments and e-cigarettes are not a safe and efficacious delivery modality for tobacco, and other loose leaf and oil based substrates," said Rich Able, a medical device marketing consultant with over 20 years of experience.
"The metal and parts composition of these devices must be stringently tested for toxic analytes and corrosive compounds," offered Able. "The FDA does not currently test any of the most popular vaping and e-cigarette instruments being manufactured at unregulated factories in Asia that source low-grade parts, batteries, and materials for the production of these devices."
Able explained that "the metals detected in this study have been associated with multiple adverse health effects under chronic conditions of exposure. Neurotoxins such as lead are linked to increased risk of cardiovascular and kidney disease. The other metals listed are even more nefarious to human organs. The strong oxidative effects of manganese can lead to necrosis (tissue death) of the mucous membrane and esophagus. Arsenic was detected in 17.9% of the aerosolized samples which can lead to significant multiple end organ damage with long term exposure."
Able believes that this and prior research is a wake-up call to the vaping industry-- in short, that it's time for things to change.
"It is critical for manufacturers of these delivery systems to design, engineer and manufacture these devices to FDA medical device quality standards. To continue manufacturing and marketing these devices to the smoking population without further diligence and clinical review is unethical and unconscionable," said Able.
Klaus Lessnau, M.D., FCCP, a pulmonologist at Lenox Hill Hospital in New York City, echoed Able's concerns.
Lessnau explained that nicotine vapor devices are used as harm reduction treatment for people who have trouble quitting tobacco products.
"It is currently believed that vapor smoking has less exposure to harmful chemical substances. However, many delivery devices use heated metal coils and aerosolize metals such as lead, chromium, manganese, nickel, arsenic and others. The vapors themselves have added chemical substances to make the smell more palatable and possible endocrine disruptor molecules are of concern," said Lessnau.
"The delivery devices and the vapors are proprietary to large companies and is currently unknown how dangerous they can be to lung health and other organs. The FDA should regulate these devices to have better knowledge about adverse effects. There is no reason to keep this information secret," added Lessnau.
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