You may not realize it but the mantles on gas camping laterns – fabric-like items that glow incredibly brightly with a relatively small amount of fuel – are radioactive. They contain thorium, enough to the point that there are warning labels on these lanterns.

Turns out there’s thorium under what will probably become a parking lot for a new shopping center in Manchester, reports the Union-Leader.  The element was used as part of manufacturing at the former Osram/Sylvania lightbulb factory, which “was licensed by the then-Atomic Energy Commission in 1965 to use thorium-dioxide to coat electrodes in high-intensity light bulbs. The process was discontinued in February 1986. ”

Some of the radioactive material leaked into the soil and was left behind when the plant shut – as companies are wont to do with messes that are expensive to clean up.

The soil contamination was discovered in 1986 when GTE Sylvania hired General Dynamics to decommission the site, said Michael Dumond, chief of Public Health Protection for the state, in an email.  “During this task, it was determined that encapsulation would be a necessary option due to discovery of soil contamination.”