Urban mining is increasingly being taken seriously by industry because it gives access to materials—such as expensive metals used in electronics—that are buried in waste tips and landfills.

Multiple disasters can have a cumulative impact leading to great human and financial loss. The awareness of all possible risks is of fundamental importance.

Twenty five years ago, the German chemist Michael Braungart developed a new approach to recycling, now called "Cradle to Cradle" or "C2C" after the book, Cradle to Cradle: Remaking the Way We Make Things, which he and the American architect William McDonough published in 2002.

The amount of nitrogen that is excreted by livestock is directly proportional to the amount it is fed . This is according to Chris Reynolds a researcher in nutritional physiology of ruminants  at  the University of Reading , UK.

Non-ferrous metals are increasingly in demand because of the electronics industry. "They are used in LED’s, computers, smartphones; this is a much bigger business now," says Kate Hornsby , Waste in Social Environment manager at the Technical University Aachen , Germany.