IT'S ELEMENTAL!
BARIUM LOUISA WRAY DALTON, C&EN WASHINGTON
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Y G U T R E S P O N S E TO
THE
mention of barium is resentment. "This might be a little uncomfortable," the technician told me when she said they wanted to do a test to find out what might be causing my appetite to plummet and my stomach to hurt. I don't think the word "enema" was ever brought up. But even enema is an understatement. The lower gastrointestinal exam, also known as the barium enema, entails inserting a milky suspension of barium sulfate into "the back passage," as the English say of your large
REVEALED A colored barium Xray showing a healthy large intestine (in red). intestine until it has entirely filled your colon—with more liquid than you ever thought could fit in there—and then placingyou on a coldX-ray table and askingyou to hold it... and continue to hold it... and hold it a little longer... you're doing great ... and we're getting there ... for what, under the circumstances, is a very long time. I'm sorry to get into the details, but it must be understood that "uncomfortable" just doesn't adequately describe the sensation of keeping all of that dense white fluid inside of you. Ancient reflexes well honed by evolution launch all their weight against this modern medical procedure. At least mine did, although I must grant that I was 10 years old and under a certain amount of stress already. After one bad 134
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traumatic barium enema experience, and with a surprised and unrepentant look, she said, "Gee, we order those all the time." I now grudgingly admit she has good reason. Despite my reflex resentment toward barium, it seems I owe it my
life. night two months earlier, I had been strugBarium sulfate has been entering gasgling with frequent stomachaches, a lowtrointestinal tracts for nearly 100 years begrade fever, high white blood cell count, no cause the stuff works [Science, 3 0 0 , 936 desire to eat, and general malaise. My moth(2003)]. Most of the human midsection er knew something was terribly wrong, beis invisible to X-rays, which pass right cause my appetite usually took care of all of through soft tissue, yet particles my siblings' leftovers. But I had of heavy barium sulfate block Xno sharp pain, and our family rays. The film of a barium enema doctor was perplexed: thus the shows in sharp relief all gashospital tests. The barium enetrointestinal curves and abnorma did the trick. It outlined my malities. (For the small intestine, inflamed and half-burst appenthere's a similar test, except that dix covered up with scar tissue. the barium sulfate is made into That meant that when I came a palatable "barium meal," and out from the loo, I was promptCELEBRATING it gets sent down the hatch.) C&EN'S ly told that I would now be go80TH It works so well for perhaps ing into surgery—a word that ANNIVERSARY the same reason I wanted it out scared the bejeebers out of me. of me: Barium sulfate is uncomI tliink that's when I lost it, begmonly dense. The substance is found natging my mom to not let them take me, right urally in Earth's crust as a mineral called up until they put me under. barite, which the oil industry found was I once told my doctor friend about my heavy enough to use as a "weighting agent." About 98% of the barite in the world is BARIUM AT A GLANCE put to use by petroleum firms, which grind it up and add it to drilling muds to help Name: From the Greek barys, heavy. counteract the high pressures found at oilAtomic mass: 137.33. drilling depths. History: Swedish chemist Karl Wilhelm Besides being heavy barium sulfate does Scheele distinguished baryta (a barium little else —which is yet another boon. Both alkali) from lime in 1774, but the pure doctors and oil-well diggers love it because element was discovered by British it just sits there, impeding X-rays or counchemist Sir Humphrey Davy in 1808. Occurrence: Found most often as bariteracting pressure. The compound is inum carbonate and barite. The pure soluble in water and loath to react in othform must be derived through electroler ways. Even in an intestine designed to digest, barium sulfate goes in and comes ysis of barium chloride. right back out. Appearance: Silvery white, soft metal. O t h e r barium compounds aren't so Behavior: Oxidizes quite easily and must be stored under petroleum or oil harmless. Potters like to use barium carto exclude air. Extremely toxic when bonate to lower the melting point of a soluble. Barium chloride, a soluble glaze, but are advised to wear a mask and salt, causes heart problems, but insolgloves because even the dust is soluble and uble barite is used as a tracer for Xtoxic. And the barium chlorate that makes raying the human intestinal tract begreen fireworks is rather unstable (C&EN, cause it is extremely dense and opaque July 2,2001, page 30). to X-rays. ^et barium sulfate is approachable. It Uses: Used as a "getter" in vacuum may be dense and more than uncomforttubes. The sulfate is used in paint, in Xable to have inside my colon. But give me ray imaging, and glassmaking. Barite a minute to swallow my childhood trauma, is used in drilling fluids for oil and gas and I'll raise a grateful toast to the element exploration. Barium carbonate has that lights up intestines. been used as rat poison. Barium nitrate and chlorate are used in greencolored fireworks. Barium is also used to make spark plugs.
Louisa Dalton is an assistant editor in the science, technology, and education group at C&EN. To this day, she regards eating someone else's leftovers as a sign of good health. HTTP:'//WWW.C EN-.0N LtNE.ORG,
