Talking to Your Teen Who Vapes University of Rochester Medicine E cigarette flavors are toxic to white blood cells, warn scientists Vaping Harmless. Vape aerosol contains toxic chemicals like formaldehyde, arsenic, lead, chromium, and nickel. They damage lungs. They harm developing brains. They raise cancer risks. We If you vape, you inhale a lot of harmful substances. These can damage your heart and lungs.