What's New?
•	August Newsletter
•	August ORS
•	August Journal

Upcoming Events
•	IRPA 12 19-24 October 2008
•	HPS Midyear Meeting Recent Advances in Planning and Response to Radiation Emergencies 31 January - 3 February 2009 San Antonio, Texas
•	54th Annual Meeting of the Health Physics Society 12-16 July 2009 Minneapolis, Minnesota

23 July 2008

Answer to Question #901 Submitted to "Ask the Experts"

Category: Historical Issues/Applications

The following question was answered by an expert in the appropriate field:

Shielding containers are often referred to as "pigs." Why is that?

The origin of "lead pig," like that of many words and phrases, is uncertain. As a rule, the most likely explanation is the simplest. The term "pig" has been used for many years to refer to small crude castings of lead and iron. It is derived from the practice of pouring the molten metal into a trench—branching off from the central trench were a number of short molds. The overall appearance was that of newborn pigs suckling—the molds were the "pigs" and the central trench was the "sow." Originally, the trench was simply carved into the ground and the molds (pigs) were holes dug into the bottom of the trench. It is not known when the term "pig" was first applied to the lead shields used to carry radioactive sources. Nevertheless, it is likely that it was first used by the personnel who were asked to cast the shields.

Paul Frame, CHP, PhD

Answer posted on 14 May 2001. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.