Wal-Mart signs to be used as dirty bomb?

Not that surprising. I've assumed that most products from Wal-Mart are radioactive. From Raw Story:

A little over a year ago, a routine audit at Wal-Mart reported a few missing exit signs at the company's stores and warehouses. As the audit continued, more and more signs turned up missing, and a month ago, Wal-Mart revealed that as many as 20% of the 70,000 signs at its 4500 facilities cannot be accounted for, a stunning total of 15,800 signs in all.

This would be of no particular concern -- except that the signs are radioactive. They contain tritium gas, a form of hydrogen which is used for emergency exit signs because of its ability to glow in the dark when the power goes out.

Tritium is not radioactive enough to be considered dangerous on casual contact. But if eaten or inhaled it can become absorbed into the body and may lead to cancer or reproductive abnormalities. Sean-Patrick Stensil of Greenpeace Canada told the Toronto Star, "The problem is that because it's hydrogen it can actually become part of your body. The radiation doesn't emit far, but when it actually becomes part of your cell it's right next to your DNA. So for a pregnant woman, for example, it can be really dangerous."

There are more than 2 million such signs in North America, and their use and disposal is supposed to be monitored by the U.S. Nuclear Regulatory Commission. Despite this, broken signs are often simply thrown away and wind up leaching their tritium into landfills. In February 2006, the Pennsylvania Department of Environmental Protection found that more than half of its water measurements downstream from landfills showed tritium levels that violated EPA guidelines for drinking water.

The NRC, whose records reveal a long series of event notification reports concerning Wal-Mart, has been seriously shaken up by the oversight failure. On January 16, it sent out a request for "61 organizations to check tritium exit signs in their possession against their records and to report any lost or missing signs to the agency."