The Hidden Radioactive Danger of Mantle Lamps

The hidden radioactive danger of mantle lamps may pose a health threat, including mantle lamp consumer action, thorium and health risks and mantle lamp comparisons.


| November/December 1982



078-058-01

Although most people are unaware of the problem, the mantles in such lamps are actually radioactive . . . possibly enough so to threaten the health of folks who depend on them.


PHOTO: MOTHER EARTH NEWS STAFF

The lantern—long a standby source of light—may pose a health threat due to radioactive danger from mantle lamps. (See the mantle lamp photos in the image gallery.)

The warm yellow glow of an open-flame kerosene lamp is comforting and—under the right circumstances—even romantic, but almost anyone who's tried to read by the light of one of the standard wick-type lanterns fully appreciates the usefulness of the mantle lamp. When the mantle (a small cylindrical hood, which—when placed over a flame—becomes white hot and gives off very bright light) was incorporated into the design of gas, kerosene, and oil lamps about 100 years ago, the light intensity of such devices jumped from about 15 watts to nearly 60. With this refinement, folks were significantly more able to continue their daytime activities after darkness fell than they'd ever been before!

Today, many campers and residents of non-electrified areas (as well as individuals who have chosen to do without electricity) rely on light provided by mantle lamps for reading, sewing, and other close work . . . and they've been pretty danged grateful for that eye-saving illumination, too. However, although most people are unaware of the hidden radioactive danger of mantle lamps. The mantles in such lamps are actually radioactive . . . possibly enough so to threaten the health of folks who depend on them.

The mantles used on modern lanterns acquire their radioactive properties during the manufacturing process. First, the fabric that will eventually form the small rayon mesh pouches is dipped into a solution of thorium and cerium nitrates. The nitrates are then precipitated into the cloth with ammonia, and—after it's dried—the mantle is coated with nitrocellulose, which fixes the ammonia salts and improves the pre-burning capability of the material. Occasionally, a manufacturer will also add a small amount of beryllium to give the ash (the residue that's left behind after the lantern's nitrocellulose-assisted initial burn) greater strength. However, it's the thorium in the mantle that incandesces and gives off the functional white light.

Unfortunately, that same element is radioactive. It is—to be more precise—an alpha-particle-emitting radioisotope which has a decay series of ten radiodaughters (a "daughter" is an element that is an immediately produced by-product of the disintegration of a radioactive element). The first radiodaughter is radium 228, a betaemitter which—in time—produces subsequent alpha-emitting radiodaughters.

The difference between alpha and beta particles is an important one for lantern users to understand. Both types of emissions are referred to as short-range radiation: Alpha particles are large and slow-moving, and can easily be stopped by such a barrier as a piece of paper or the glass chimney of a lantern . . . while beta particles are smaller and faster, and can penetrate body tissue. Either type can pose a health risk to the body if its emitters (in this particular case, thorium and radium) are inhaled or ingested . . . with the alpha particle being the more dangerous.

oinc
6/14/2015 7:00:55 PM

Yeah, growing up I used to care spare mantles in my field jacket, then in high school on a friends shrimp boat. We used these lanterns. Many a time I changed one, on a boat the lanterns get knocked around, hands would have the mantle ash. Never thought about washing hands off, hey, we were on a working boat. Years later in my 30s saw the huge shipping box a store had sitting on the floor for a restock. There in big letters, radioactive Logo was the warning. Loved, just lovely.


mike zajchenko
11/7/2011 12:01:48 AM

Aladdin lamp mantels have been non-radioactive since 1990, I live and own an organic estate in england, my home is off grid compleatly and my farms organic. I have many aladdin lamps and you can call and speak to the director if u dont believe me. I have 12 couples living on my estate off grid and I always buy them a aladdin when they move in. I would hate the misinformation about radioactive mantels to put people off a very green burning lamp, that can heat a room and give off light and can use synthetic "green" fule. Prof.M.zajchenko.






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