This document provides information about substance abuse, with a focus on tobacco and alcohol. It discusses the composition of tobacco and cigarette smoke, noting they contain over 4,000 chemicals including nicotine and carcinogens. The health effects of smoking include increased risk of cancer, cardiovascular and lung diseases. Smoking during pregnancy can also increase lead levels in mothers and impact fetal development. The document also discusses sheesha/hookah smoking and notes it contains high levels of nicotine, carbon monoxide and tar. A section on alcohol discusses low risk drinking guidelines and factors impacting blood alcohol levels.