Secondhand smoke may be a substantial contributor to lead levels found in children and adolescents, new study finds Passive smoking (secondhand smoke) is extremely harmful to children, especially infants. Because infants breathe faster than adults, they inhale more smoke toxins per minute. This exposes them to dangerous chemicals like nicotine, E Cigs and Second Hand Vaping: Dangers and Protections Experts Warn About the Lifetime Effects of Secondhand Smoke in Children CardioSmart American College of Cardiology