In the past terrorists have left bombs in bins. The bomb is much less likely to be spotted than an unattended bag and the metal bins provide extra shrapnel that injures people nearby when it detonates. For this reason there are no bins in most railway stations, most airports and many shopping centres in the world, or if they are provided they are just a bin bag hanging from a metal hoop.
Tierney also points out that "the prices paid for scrap materials are a measure of their environmental value as recyclables. Scrap aluminum fetches a high price because recycling it consumes so much less energy than manufacturing new aluminum."
Levels of metals recycling are generally low. In 2010, the International Resource Panel, hosted by the United Nations Environment Programme (UNEP) published reports on metal stocks that exist within society and their recycling rates. The Panel reported that the increase in the use of metals during the 20th and into the 21st century has led to a substantial shift in metal stocks from below ground to use in applications within society above ground. For example, the in-use stock of copper in the USA grew from 73 to 238 kg per capita between 1932 and 1999.
The wheelie bin is a waste container on wheels designed to make it easier for users to transport heavy loads of refuse to the curb or other pick-up point. George Dempster invented the Dempster-Dumpster system in the 1930s for automatically loading the contents of standardized mobile steel containers onto the dustcart. This led to the classic Dempster Dumpmaster waste collection vehicle of the 1950s, but wheelie bins did not become commonplace until the 1970s. The term dumpster is frequently used as a generic term for a large MGB or the non-mobile variety (known as a skip in the UK or Australia) in the United States.
In the US residential wheelie bins are also generically called "Herbie Curbies." The modern bin is a German invention of the 1970s in a patent held by Schneider, and licensed to other companies outside Germany.
Economist Steven Landsburg has suggested that the sole benefit of reducing landfill space is trumped by the energy needed and resulting pollution from the recycling process. Others, however, have calculated through life cycle assessment that producing recycled paper uses less energy and water than harvesting, pulping, processing, and transporting virgin trees. When less recycled paper is used, additional energy is needed to create and maintain farmed forests until these forests are as self-sustainable as virgin forests.