Metal is not something that the human body is designed to digest. Unlike food which can be broken down and absorbed, metal is inorganic and cannot be processed by the digestive system. Eating metal would be extremely harmful and dangerous.
What Happens If You Swallow Metal?
If someone was to swallow a small piece of metal like a coin, screw, staple, or jewelry, it would likely pass through the digestive tract without causing much damage. However, larger pieces of metal pose significant risks.
Metal objects can get stuck in the esophagus, stomach, or intestines, resulting in a blockage. This can cause severe pain, nausea, vomiting, perforations, infections, and even death if not treated quickly. Surgery may be required to remove the obstructing metal object.
Sharp pieces of metal like nails, needles, or razor blades can puncture or lacerate the lining of the digestive tract. This can lead to bleeding, infections, abscesses, and peritonitis. Surgery is often needed to repair perforations and stop bleeding.
Metal objects may also obstruct or tear the intestines if they have sharp edges or points. This can allow intestinal contents to leak into the abdominal cavity causing a life-threatening condition called peritonitis.
Some metals contain toxic substances like lead, arsenic, mercury, or cadmium which can leach out and be absorbed into the body. This metal poisoning can damage the kidneys, liver, and nervous system.
Swallowing magnets, like those found in magnetic building sets, are extremely dangerous. If more than one magnet is swallowed, they can attract each other while traveling through the intestines. This can pinch or twist the intestines, causing blockages, perforations, infections, and death.
Can Digestive Acids Break Down Metal?
The digestive system uses acids and enzymes to break down and digest food. However, these digestive juices have no effect on inorganic metal objects. Stomach acid and digestive enzymes cannot break metals down or make them any easier or safer to pass.
Hydrochloric acid in the stomach has a pH between 1.5 to 3.5. This is strong enough to dissolve many metals over time, such as iron, copper, zinc, and aluminum. However, the stomach emptying into the small intestine limits metal exposure to stomach acid to just a few hours.
Pancreatic enzymes like amylase, lipase, and protease work to digest carbohydrates, fats, and proteins. But these enzymes are unable to break bonds or alter the structure of indigestible inorganic metal.
So while strong acids and enzymes are excellent at processing food, they have little to no effect on metal objects that are swallowed. The metal cannot be altered or broken down to make it less harmful.
Can the Body Absorb Nutrients from Metal?
The digestive system allows the body to extract vital nutrients from food to provide energy, build and repair tissue, and regulate systems. This is done by breaking food down into molecules that can pass through the intestinal wall into the bloodstream.
Since metal cannot be broken down by the digestive process, the body is unable to absorb any nutrients from it. Ingested metal just stays in solid form as it passes through the gastrointestinal tract.
Some metals found in food or water, such as iron, zinc, and magnesium, can dissociate into ions that are small enough to be absorbed. But swallowing a piece of metal does not release any beneficial ions or nutrients.
In some rare cases, small amounts of metals can be absorbed if the object breaks down significantly. This is very rare with larger metal objects but can occur over time with metallic dusts or shavings that oxidize.
So while trace metals are vital to human health, swallowing metal objects or jewelry will not provide any nutritional benefit. The metal cannot breakdown into an absorbable form to release useful ions or compounds.
Can the Body Excrete Metal Waste?
Since metal cannot be altered or digested, anything swallowed will eventually need to be excreted from the body as solid waste. Smaller metal objects are typically passed in the feces within a few days.
The time it takes to pass depends factors like:
- Size and shape of the object
- Location it becomes stuck in
- Bowel obstructions
- Bowel motility
Larger objects may need to be surgically removed if they cause a dangerous blockage or perforation. In some cases, very small metallic objects can become lodged in intestinal tissue long-term.
Most metal that is swallowed will pass through the digestive system without being broken down or absorbed, and exit the body in the feces. However, larger objects pose serious risks and require emergency care if stuck in the intestines.
Special Cases of Metal Ingestion
Lead Poisoning from Lead Objects
Swallowing metallic lead objects is especially dangerous as lead is toxic. Lead poisoning most commonly occurs from swallowing lead paint chips, but ingesting lead bullets, fishing weights, or lead jewelry can also cause poisoning.
As the lead object passes through the stomach, small amounts of lead can dissolve from its surface. Even tiny amounts of dissolved lead can be absorbed into the bloodstream, quickly causing poisoning. Lead affects the brain, kidneys, and nervous system.
Mercury Exposure from Swallowing Liquid Mercury
Swallowing liquid mercury, sometimes called quicksilver, is extremely hazardous but rarely occurs. If liquid mercury from a broken thermometer or other device is swallowed, it can release toxic mercury fumes inside the gastrointestinal tract.
These absorbed mercury vapors affect the kidneys and brain. Emergency care is vital after swallowing any amount of metallic mercury.
Magnets Sticking Together Through Intestinal Walls
If more than one magnet is swallowed, they can attract through intestinal walls causing life-threatening damage. The pressure can destroy intestinal tissue, causing blockages, tears, or even intestinal twisting.
Surgery is often urgently needed to cut apart the magnets or remove damaged sections of intestine. Parents must keep magnet sets away from small children due to this hazard.
Heavy Metal Toxicity from Metallic Dust or Shavings
While large metal objects pass through undigested, smaller metal particles are more concerning. Metallic dust, shavings, or powders can release ions over time, especially as they contact stomach acid.
If fine particles of toxic metals like cadmium, arsenic, lead, or mercury are swallowed, significant amounts can dissolve and get absorbed into the bloodstream. This gradually leads to poisoning as small exposures accumulate.
Dangers to Specific Populations
Children are especially prone to swallowing small metal objects like coins, magnets, buttons, jewelry, or toy parts. Their natural curiosity and mouthing behaviors make this common.
Since children have smaller anatomical structures, metal objects more easily get lodged in their airways or digestive tracts. A coin or button that might pass harmlessly through an adult can obstruct a child’s esophagus.
Parents must keep small metal objects out of reach and monitor children closely. Seek immediate care if any object is swallowed to remove it before it causes damage or poisoning.
Individuals with Intestinal Disease
Those with weakened intestinal walls from disease are at high risk for perforation or rupture if they swallow metal objects. This includes individuals with:
- Inflammatory bowel diseases like Crohn’s or ulcerative colitis
- Recent intestinal surgery
- Intestinal scarring from radiation
- Intestinal adhesions
Those with narrowed intestinal openings may also have blockages from smaller objects. Individuals with intestinal conditions should always seek prompt care if they swallow metal.
Individuals with Orthopedic Devices
People with orthopedic devices like artificial hip or knee joints, screws, plates, or pins may set off metal detectors. While inconvenient, this does not indicate the metal device is breaking down.
These implanted orthopedic devices are surgical grade stainless steel or titanium, carefully designed to tolerate body fluids and pressures. The metal does not dissolve or leach out, and swallowing does not impact the stability of these medical implants.
Diagnosis of Metal Ingestion
If metal ingestion is suspected after swallowing or choking on an object, urgent medical evaluation is needed. Warning signs include:
- Difficulty breathing
- Abdominal pain
- Bloody stools
To diagnose the presence and location of ingested metal, doctors may use:
- X-rays – Visualize metallic objects lodged in the esophagus, stomach, or intestines.
- CT scans – Provide 3D images to pinpoint the location of metal objects.
- Endoscopy – A tiny camera on a flexible tube passed down the throat to view metal objects stuck in the esophagus or stomach.
- Colonoscopy – A camera passed through the rectum to see the lower colon and metal objects stuck in the large intestines.
Blood tests may reveal elevated lead levels after swallowing lead. Let your doctor know immediately if any type of metal was swallowed, even if accidental.
Treatment for Metal Ingestion
Treatment depends on the type of metal swallowed, amount, and location stuck in the intestines. Some options may include:
- Endoscopic removal – Instruments passed down the throat or up through the rectum to grasp and pull out objects lodged in the esophagus, stomach, or rectum.
- Surgical removal – Requires operating to cut open the abdomen and intestines to access swallowed objects.
- Bowel rest – Not eating or drinking to allow complete bowel rest while metal passes through. Often used for children who swallow button batteries.
- IV fluids – Provides hydration and nutrition during periods of bowel rest when not eating.
- Medications – Stool softeners or laxatives to ease the passage of small metal objects through the intestines.
- Antidotes – Medications to bind with dissolved metals, like chelators for acute lead poisoning.
Parents must keep small metal objects like coins, magnets, and batteries safely out of reach of infants and toddlers. Seek immediate medical care if your child swallows metal.
Preventing Metal Ingestion
Here are some tips to help prevent accidental metal ingestion:
- Keep batteries, bullets, jewelry, magnets, and screws safely locked away from children.
- Dispose of damaged items like rusty razor blades, broken pens, and tacks properly in sealed containers.
- Wear protective gear when working with metal dusts and shavings to prevent inhalation or hand to mouth exposure.
- Consider using bittering agents on metal objects to discourage chewing.
- Carefully isolate any liquid mercury spills on a hard surface using gloved hands and index cards. Do not vacuum.
- Supervise young children closely and teach them not to put nonfood objects in their mouths.
Swallowing metal can happen unexpectedly, especially with small children. But taking proper precautions reduces this risk. Call for help immediately if someone swallows a concerning metal object.
While trace amounts of some metals are essential nutrients, swallowing solid metal objects provides no health benefits and poses many risks. The body cannot digest or absorb nutrients from inorganic metals.
Smaller metal items may pass through uneventfully. But larger objects can obstruct intestines or puncture tissues, requiring emergency surgery. Objects that stay in the body can cause infections or poisoning over time.
Caregivers must keep dangerous metals safely out of reach of children and supervise closely. Prompt medical care can help retrieve lodged objects and treat any resulting damage. With vigilance, we can prevent unfortunate and unintended metal ingestion.