(Reuters Health) - Exposure to secondhand vape at home may be linked to a heightened risk for respiratory symptoms in young adults, a new study suggests.
An analysis of data from 2,090 young people who signed on for the study when they were in their late teens reveals that exposure to second hand vape was associated with a 40% increased risk of bronchitic symptoms and shortness of breath, according to the report published in Thorax.
"The take home message is that second-hand nicotine vape (SHNV) exposure should not be perceived as harmless," said coauthor Dr. Talat Islam of the University of Southern California. "The potential detrimental effect of SHNV exposure can be much greater for children who themselves are not smokers or vapers."
Although the study did not address potential mechanisms, Dr. Islam suspects that chemicals in the vape liquids may be the problem.
"Vaping devices heat the e-liquid that contains a myriad of chemical compounds including flavoring agents like diacetyl and 2,3-pentanedione," Dr. Islam said in an email. "The SHNV aerosol may contain lower levels of nicotine and larger particulate matter than cigarette smoke; but it can contain high levels of ultra-fine particles that can reach deep down the lungs, and chemicals like aldehydes and toxic metals."
"As a bystander, when we inhale this aerosol, we are exposing our lungs to the harmful effects of those substances," he added.
The U.S. Centers for Disease Control and Prevention notes on its website that in occupational settings, inhalation of diacetyl, which is a byproduct of heated buttery flavor, can cause 'flavoring-related lung disease'.
"I think similar mechanisms are at play for SHNV exposure," Dr. Islam said. "But we should not only focus on any single agent in the SHNV aerosol, as it is a pollutant mix like cigarette smoke or traffic exposure that (contains) chemical residues, particulate matter, toxic metals, and others that can cause injury to the lung tissue."
To take a closer look at the impact of SHNV, Dr. Islam and his colleagues turned to data from the Southern California Children's Health Study, which collected detailed information annually on respiratory health, active and secondhand nicotine vaping and conventional tobacco and cannabis smoke exposure households from 2014 to 2019.
The researchers considered participants to have bronchitic symptoms if they reported any of the following: bronchitis in the previous 12 months; daily cough in the morning for three consecutive months; daily cough at other times of the day for three months in a row; congestion or phlegm that was not associated with a cold. Wheeze was defined as any report of wheezing or whistling in the chest during the previous 12 months. The participants were considered to have shortness of breath if they reported having been troubled by shortness of breath when hurrying on level ground or walking up a hill.
Dr. Islam and his team found that exposure to secondhand nicotine vape increased from 11.7% to 15.6% between 2014 and 2019. The prevalence of wheeze, bronchitic symptoms and shortness of breath ranged from 12.3% to 14.9%, 19.4% to 26.0% and 16.5% to 18.1%, respectively, during the study period.
After accounting for vaping, active and passive exposure to tobacco or cannabis, and demographic characteristics such as age, gender, race/ethnicity and parental education, the researchers found associations of secondhand nicotine vape exposure with bronchitic symptoms (OR 1.40, 95% CI 1.06 to 1.84) and shortness of breath (OR 1.53, 95% CI 1.06 to 2.21). They observed no association with wheezing after adjustment for potential confounders.
The associations were strengthened when analysis was restricted to participants who were neither smokers nor vapers.
"I just wonder," Dr. Islam said, "why do we, the people, need to prove whether or not some commercially profitable exposure - with no beneficial effects - is potentially detrimental to public health? Shouldn't the burden fall more heavily on industries to clearly demonstrate and establish that their products are not harmful before they expose us to them?
While the new study does not prove that secondhand vape causes respiratory issues, "it's a hypothesis generating paper," said Dr. Panagis Galiatsatos, an assistant professor in the division of pulmonary and critical care medicine and director of the Tobacco Treatment Clinic at Johns Hopkins Medicine.
Dr. Galiatsatos hopes the paper will spur more research into what "many of us fear: what comes out of the lungs of a vaper goes into the lungs of others. I commend these researchers for generating these types of conversations. Just as with cigarettes you don't want someone else to suffer the consequences of your vaping."
A big concern, Dr. Galiatsatos said, is the rising numbers of people who never smoked but who are now vaping.
SOURCE: https://bit.ly/3FxzXYU and https://bit.ly/3nvU7wc Thorax, online January 10, 2022.
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