Small Bytes on Computer Recycling  by James Kaznosky

Did you know that waste electronic equipment is the fastest growing category of waste in the US?  In 2008, the EPA estimated 3.16 million pounds of electronic waste was designated for disposal with approximately 18% of this material recycled.  Much of the electronic waste stream contains heavy metals, such as lead, mercury, cadmium and other hazardous constituents.  One component of Columbia University’s continued commitment to environmental protection is focused on computer recycling.  For the past decade, Columbia University has been recycling computers and other electronics when they become obsolete.

Waste computers and electronics can often find another “life” through repurposing efforts, whereby this equipment is donated as-is, or is refurbished and donated, providing useful technology to those who otherwise would not have such access.  It is important to be aware that before a computer is designated for recycling or repurposing, it is the responsibility of the end user to ensure that sensitive data are cleansed from the hard drive. Deleting files or simply reformatting the hard drive will not stop someone intent on recovering private, personal or confidential data from your computer.  CUIT’s  “Data Sanitization/Disposal of Electronic Equipment Policy” outlines the procedure for cleansing electronic equipment of sensitive data.  CUIT also provides the Columbia community with DBAN, an easy to use program that erases all data from a hard drive.  Visit for more information on Columbia’s recycling programs.

Depleted Uranium (DU): Civilian and Military Use  by George Hamawy

Depleted uranium DU (mostly U-238) is the leftover material after removing most of the valuable fissionable U-235 from natural uranium. It is weakly radioactive and the radiation dose from it is about 60% of that from natural uranium.  Due to its high density, about twice that of lead, and its low radioactivity, its main civilian uses include counterweights in aircraft, radiation shields in medical radiation therapy machines and containers for transport of radioactive materials with high activity.

The military uses DU for armor plate. Due to its high density and ignitability upon impact with a target, it is also used in armor penetrating military ammunitions, (see below).  Several United Nations studies have found that radiation levels close to DU-contaminated events may exceed background levels with highly contaminated zones requiring a cleanup operation, a difficult  proposition in a war zone.

Over time following such an event, the contamination normally becomes dispersed into the wider natural environment by wind and rain. People living or working in an affected area may inhale contaminated dust or consume contaminated food and drinking water. Most of the uranium that enters the body through ingestion is naturally eliminated. Inhaling uranium however, poses a higher risk.  The kidneys and lungs are the critical organ in each case. When an individual is believed to have been exposed to high levels of uranium, urinalysis must be performed and dialysis might be needed to eliminate the uranium.   Urynal acetate used in electron microscopes at Columbia University is made up of Depleted Uranium where the weight is the same as natural uranium while the radioactivity is much lower. For some high activity sources such as molybdenum generators, depleted uranium is used as a shielding material in transportation and storage.

Depleted Uranium

Editorial Staff: Kathleen Crowley, Chris Pitoscia, Paul Rubock
Graphics, Design, Lay-out: Jean Lee

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