This document discusses several harmful chemicals and the diseases they can cause. It explains that cancer is caused by abnormal cell growth and can affect different organs. Carcinogens like those in tobacco can cause lung cancer. Exposure to chemicals like alcohol and drugs while pregnant can harm the unborn child and cause issues like fetal alcohol syndrome. Heart disease, a leading cause of death, occurs when arteries are narrowed by chemicals like cholesterol. Kidney disease can also result from chemicals damaging the kidneys.