The bilets come to have cocaine, oil, blood, traces of feces, ash and metals, among other elements. They are acquiring such substances because it passes through millions of hands and these are an indication of their licit and illicit activities.
According to an article on the web www.intereconomía.com 94% of the bills in circulation are contaminated with bacteria susceptible to cause diseases. In fact, 7% contain Staphylococcus aureus and Klebsiella pneumoniae that can cause pneumonia or blood infections.
For more information visit the following link.
http://intereconomia.com/economia/94-los-billetes-circulacion-contaminados-20140820-0000/