Vape residue may harm unborn babies, mouse study suggests

Exposure to vape and e-cigarette residue on surfaces while pregnant could put unborn babies at risk of immune system damage, new research suggests.

Vape liquid contains propylene glycol, glycerol, and often nicotine, flavors, and other additives. When heated it can produce toxic chemicals like formaldehyde, acetaldehyde, and acrolein, a hazardous air pollutant.

“When vapes are used indoors, or in a vehicle, the vapor condenses on surfaces forming a thick, oily layer, and this residue can be absorbed through the skin,” said study co-author Distinguished Professor Brian Oliver, from the University of Technology Sydney (UTS) and the Woolcock Institute of Medical Research.

“Previous research has shown that vaping during pregnancy can cause serious harm to the baby, including increased risk of stillbirth, low birth weight and developmental problems,” he said.

In a new study, led by Dr. Chantal Donovan and Dr. Richard Kim from the UTS School of Life Sciences, pregnant mice were exposed to e-cigarette vapor residue on towels. Their offspring were then infected with flu, and their immune system response assessed.

The researchers found that in the exposed offspring, a specialized type of immune cell, called a CD8⁺ T cell, became dysregulated. CD8⁺ T cells are essential for mounting an effective immune response against infections, as well as cancer.

The study, “Maternal third hand exposure to e-cigarette vapor alters lung and bone marrow immune cell responses in offspring in the absence or presence of influenza infection,” has just been published in the American Journal of Physiology-Lung Cellular and Molecular Physiology.

Dr. Donovan said the study revealed for the first time that maternal third-hand exposure to e-vapor results in significant, long-lasting effects on lung and bone marrow immune cell responses in mice.

“The study supports the growing body of evidence of the dangers of e-cigarette exposure and highlights that even third-hand e-vapor exposure during pregnancy could have long lasting effects,” she said.

In Australia, vaping is prohibited in enclosed public spaces, including workplaces, public transportation, and restaurants, similar to smoking bans. However, there are still many areas where vulnerable people could be exposed.

“Visitors to the homes of friends or relatives who vape might not realize they’re being exposed to harmful chemicals just by touching benchtops or sitting on the couch. People who vape need to understand that this doesn’t just affect them,” Dr. Kim said.

New vaping regulations were recently introduced in Australia to restrict vape sales to pharmacies, including non-nicotine varieties, and limit flavors, to protect public health, particularly among young people.