Yes, there are minimal amounts of carcinogens if you vape your juice at very high temperatures and use certain oil-based aromas (WHO research, Fraunhofer Instutute research, Vape-Safe Aromas list), but the levels are really low and one can almot evade all the bad stuff if one vapes on regulated equipment, at reasonablevoltages, if you use only vape-safe aromas (or none at all , like I do) and no colorings at all. Always better to mix your own juice so you know all the ingredients you inhale and stay around 5 and 8 Watts (or likee 3.7-4.2V on a 1.8-2.4Ohm coil or so, there's a good calc for all the conversions). So yeah, if you don't push it, vaping is hundreds of times better than smoking.