The Bizarre Object Scientists Say Your Stomach Acid Can Dissolve

Children are particularly prone to swallowing foreign objects like coins, rings, buttons, batteries, and toys. But because teething toddlers typically don't know any better, and because pennies look so enticing, it's easy to forgive them. However, foreign objects frequently find their way into the stomachs of adults, as well. According to a 2012 German research paper published in Deutsches Ärzteblatt International, fish bones and chicken bones are the most commonly swallowed foreign objects by adults. However, adults also commonly ingest inorganic objects, too: coins, disc batteries, and even razor blades, to name a few, though that last one is especially interesting.

Fortunately, ingested foreign objects pass "uneventfully" through the body in about 80% of cases. That means no medical intervention, like an endoscopy, is necessary. But it's nearly impossible that an object, even one made of metal, could pass through an adult's digestive tract without being affected somewhat by the digestive juices that are meant to break down actual food. That's why scientists have been exploring the effects of gastric juice on materials for decades — it's good to know if a swallowed razor blade will remain intact on its way out.

One such study discovered that many common metal objects indeed break down in stomach acid. The scientists placed button batteries, razor blades, and pennies in separate containers of simulated stomach acid and recorded the effects. (They also drew data from clinical observations of one brave individual who was willing to swallow multiple razor blades in the name of science.) The findings, published in 1997 in the journal Gastrointestinal Endoscopy, revealed that an adult's stomach acid could break down a razor blade by 37% in just 24 hours, effectively rendering it dull and brittle enough to break apart easily. Curiously, the pennies were virtually unaffected, while the button batteries didn't degrade enough to leak their toxic contents – one of the major environmental problems associated with batteries.

Humans ingest all sorts of things not intended for the dinner table, but that doesn't mean that such objects are always bad for you. After all, many metals are actually essential for biological processes. The human body contains numerous trace metal elements, including iron, copper, magnesium, zinc, chromium, and gold. There are even trees that "grow" significant quantities of gold in their leaves. Therefore, most common metal objects around the house won't make you sick, but, if they're large enough, they can cause obstructions in the digestive system. In such cases, you may need an endoscopy.

The Mütter Museum in Philadelphia contains a bizarre museum collection, called The Chevalier Jackson Collection of Swallowed Objects. Dr. Chevalier Jackson, nicknamed "the Father of Endoscopy" was a prominent otolaryngologist who developed many tools and methods for extracting swallowed foreign objects from people's stomachs in the late 19th and early 20th century. The museum's collection contains those tools — as well as hundreds of the objects that Dr. Jackson extracted from patient's stomachs. There are a shocking number of metal jacks, but also bobby pins, toy ships, nails, brass buttons, and just about every other common object of the time small enough to slip down a throat.

While Dr. Jackson's methods were undoubtedly effective in saving many lives, the modern world is full of more toxic objects that can do damage if ingested. Batteries are of particular concern: Swallowed batteries can cause fistula formation (connections between different body parts), and their electric charge can even hydrolyze tissues and eat away at the lining of the digestive tract. Worse yet, batteries often contain heavy metals, like lead, which may also be found in certain toys, jewelries, bullet casings, and fishing sinkers. Maybe it's best to only swallow food and drink.