We live in the age of aluminum. However, this shiny lightweight metal has a frightening dark side that is critically examined for the first time in this book. A hundred years ago, hardly anyone knew what to do with the most abundant metal in the Earth's crust. Today, aluminum is ubiquitous. Bioactive aluminum compounds are particularly popular in the cosmetics industry: in sunscreen, aluminum promotes even distribution. In deodorants, it reacts with skin cells, preventing them from sweating. Medications for heartburn often contain excessive amounts of aluminum. Two-thirds of all vaccines contain aluminum as an adjuvant. Many water treatment plants use aluminum compounds for clarification, delivering drinking water - with inevitable aluminum residues - to households. This stands in stark contrast to the careless use of aluminum in sensitive areas.