Recent research, conducted by the Technische Universitat Munchen (TUM), has revealed elevated levels of arsenic in samples of beer. This is believed to have originated from the filtering process using diatomite, a method of purification through using diatomaceous.
While this material is able to remove particles of yeast and hops and to give the beer a crystal-clear appearance, research results show the use of diatomaceous earth could be a significant source of arsenic contamination.
Diatomite, also known as diatomaceous earth, consists of fossilized diatoms, a type of algae that lived millions of years ago. Diatom fossils contain lots of minute holes, for this reason they do a great job filtering liquids including beer and wine.