File: US authorities said last month that there had been 47 deaths this year from a lung illness tied to vaping.
PARIS - Vaping devices and the chemicals they deliver - increasingly popular among teens - may damage the cardiovascular system, a study said Thursday, adding to a growing chorus of concern over injury and deaths related to e-cigarettes.
The latest findings, published in the journal Cardiovascular Research, come after the US Centers for Disease Control and Prevention last month declared an "outbreak of lung injuries" linked to vaping.
"E-cigarettes contain nicotine, particulate matter, metal and flavourings, not just harmless water vapour," senior author Loren Wold of Ohio State University wrote in Thursday's study.
"Air pollution studies show that fine particles enter the circulation and have direct effects on the heart - data for e-cigarettes are pointing in that direction."
Nicotine, also found in tobacco, is known to increase blood pressure and the heart rate.
But other ingredients inhaled through the vaping may lead to inflammation, oxidative stress and unstable blood flow, Wold said.
Ultrafine particulate, for example, has been linked to thrombosis, coronary heart disease and hypertension, among other conditions.
E-cigarettes also contain formaldehyde, which has been classified as a cancer-causing agent and associated with heart damage in experiments with rats.
Moreover, almost nothing is known about the potential health hazards of flavouring agents that mimic the taste of mint, candy or fruits such as mango or cherry, the study noted.
"While most are deemed safe when ingested orally, little is known of their systemic effects following inhalation," the researchers wrote.
To assess possible impacts on the heart and vascular system, Wold and colleagues undertook a systematic review of medical literature, which remains thin due to the newness of e-cigarette use.