Researchers at McGill University, Canada, exposed mice to 60 puffs a day They found rodents had signs of lung damage within one month Vaping has become an epidemic in America's youth amid glitzy adverts

Vaping for just one month leads to DNA damage that is comparable to smoking tobacco, another damning study of e-cigarettes suggests.

Researchers at McGill University in Montreal, Canada, exposed mice to the equivalent of 60 puffs of a mango-flavored Juul device per day for four weeks.

America is currently in the grips of a vaping epidemic among children that has been blamed on child-friendly flavoring and glitzy shop window displays.

Testing also revealed alterations in hundreds of genes in macrophages — another type of white blood cell involved in the immune response to infection or damage.

She added: 'We show low level chronic exposure aerosols has local immunomodulatory effects, and drastically changes protein and RNA expression in important pulmonary sites.'