What is Copper Toxicity?
Copper is a mineral found in high amounts in the brain, liver, and kidney. Due to their larger size, bones and muscles contain more than half of the body’s copper. The liver attaches copper to a substance called ceruloplasmin and carries it to other parts of the body. About half of the copper in the body is gotten rid of in the bile, and the rest is removed through other digestive tract secretions. This makes the digestive system the key controller of copper levels in the body.
Copper is necessary for many proteins in the body and helps them to perform their roles. However, too much copper can damage cells. The amount of copper in the cells is determined by a balance between how much is taken in and how much is removed. Too much copper can cause not only stress to the cells but also DNA damage and hindered cell growth. Consuming more than 1 gram of a chemical compound of copper can lead to signs of toxicity.
Copper toxicity can occur due to an inherited metabolic disorder (known as primary copper toxicosis) or result from consuming too much copper, absorbing too much, or not getting rid of enough due to other diseases (known as secondary copper toxicosis). Consuming acidic foods cooked in uncoated copper cookware, or exposure to excess copper in drinking water or in the environment, can also lead to copper toxicity.
What Causes Copper Toxicity?
Copper toxicity typically happens when people unintentionally consume or expose themselves to water, topical creams, acidic foods, or other substances that contain excessive amounts of copper. This can happen in various ways, including through contaminated water, burn-treatment creams that have copper salt, acidic foods cooked in copper pots without protection, or in some extreme cases, attempted suicides. Note that a lethal dose of copper means consuming around 10 to 20 grams.
Copper sulfate, which is available in many places even without a prescription, is a commonly used chemical. It’s often used in farming as a pesticide, in the leather industry, and even in creating homemade glue. Some people burn copper sulfate for good luck and religious practices, particularly among Buddhists and Hindus.
The bright blue color of hydrated copper sulfate crystals can appeal to children, leading to accidental poisonings. There’s also a rare inherited disorder called Wilson’s disease, in which the body stores excessive amounts of copper, due to mutations in a specific gene that encodes a copper-processing enzyme.
Normally, the copper in our blood exists in two forms: the majority is bound to a protein called ceruloplasmin, and the remaining amount is “free”, loosely attached to albumin and other small molecules.
Risk Factors and Frequency for Copper Toxicity
Copper poisoning isn’t common in Western countries, but it’s more frequently seen in South Asian rural areas. Newborns and infants are at a higher risk because their bodies aren’t yet fully equipped to get rid of the excess copper. There are also specific conditions, such as Indian childhood cirrhosis, endemic Tyrolean infantile cirrhosis, and idiopathic copper toxicosis, which involve an overload of copper in the body.
- Copper poisoning is less common in Western countries.
- It is more prevalent in rural areas in South Asian countries.
- Newborns and infants are at higher risk due to immature biliary excretion systems and increased intestinal absorption.
- Conditions like Indian childhood cirrhosis, endemic Tyrolean infantile cirrhosis, and idiopathic copper toxicosis are associated with excessive copper in the body.
Signs and Symptoms of Copper Toxicity
Acute copper toxicity is a condition that can occur when too much copper is present in the body. The signs and severity of this condition can vary depending on the way the body is exposed to the copper.
Often, people who have ingested too much copper will experience stomach issues such as:
- Abdominal pain
- Blood in vomit or stool
- Dark-colored, sticky stool
- Yellowing of skin and eyes (jaundice)
- Lack of appetite
- Extreme thirst
- Diarrhea
- Vomiting linked with damage to the stomach lining
In some cases, people may also see blue-green material in their vomit or stool – this is a strong sign of copper toxicity. Other symptoms may include:
- Changes in mental state
- Headache
- Coma
- Rapid heart rate
Those who have received too much copper through intravenous methods (such as through contaminated fluids used in kidney dialysis) may experience symptoms of blood cells breaking apart inside their blood vessels. People with a certain metabolic condition (Glucose-6-phosphate deficiency) are at an increased risk of experiencing blood-related side effects due to copper toxicity.
On the other hand, neurological symptoms like depression, fatigue, irritability, hyperactivity, and difficulty focusing may also occur. In severe cases, copper toxicity can lead to serious problems like:
- Breakdown of muscle fibers (rhabdomyolysis)
- Heart and kidney failure
- An accumulation of an abnormal form of hemoglobin (methemoglobinemia)
- Breakdown of red blood cells in the blood vessels (intravascular hemolysis)
- Liver cell death (hepatic necrosis)
- Brain disease (encephalopathy)
- Death
Testing for Copper Toxicity
If your doctor suspects you might have copper toxicity, they will typically begin by testing your urine and blood copper levels, as well as serum ceruloplasmin levels. These tests are the most common ways to initially evaluate copper toxicity.
In cases of serious copper poisoning, your doctor might also check the copper levels in your stool. Additionally, they may perform lab tests to check the health of your kidneys, determine whether the cells in your blood are breaking down, or assess potential liver damage. These tests for liver function will generally include something called ASL/ALT, which is likely to be higher than normal if you have copper toxicity.
During a crisis where the red blood cells are breaking down rapidly (hemolytic crisis), you might also have tests for methemoglobinemia and other signs of red blood cell lysis. A common finding during this crisis can be a decrease in blood glutathione levels.
Treatment Options for Copper Toxicity
Treating copper poisoning focuses on implementing these four main principles: lessening the absorption, closely monitoring the patient, giving necessary help based on the patient’s needs and executing chelation therapy (a chemical technique that removes copper from the body).
In the early stages, high doses of zinc can be effective in holding off the appearance of symptoms. This is because zinc actually competes with copper for absorption in our digestive system. Zinc also triggers a natural protein in our bodies called metallothionein, which has a special skill of binding with copper more than it does with zinc, keeping copper from entering the bloodstream.
The primary drug used to tackle copper toxicity is D-Penicillamine, although other substances like EDTA (Ethylenediaminetetraacetic acid) and DMPS (dimercaptopropanesulfonic acid) may also be used to treat copper poisoning. However, about 30% of patients might not handle long-term therapy with these substances since they could produce side effects. This treatment might not be best for patients with symptoms affecting the nervous system.
For those who can’t handle D-Penicillamine, Trientine is often used as an alternate solution to help increase the release of copper through urine. In extreme cases, a liver transplant may even be necessary. But it’s not usually recommended for patients showing neurological or mental symptoms.
Another possible treatment is ammonium tetrathiomolybdate, but this hasn’t been approved in the US yet. For really severe cases, procedures like plasmapheresis (where the plasma is separated from the blood), exchange transfusion, MARS (molecular adsorbent recirculating system), or dialysis (a process to purify the blood) could be required to act as temporary solutions before a transplant is done, if it’s decided that a transplant is needed.
What else can Copper Toxicity be?
Other types of poisoning due to heavy metals can show similar symptoms, so they need to be considered as well. In children, long-term exposure to copper can cause symptoms that closely resemble a condition called Pink Disease, also known as Infantile Acrodynia.
What to expect with Copper Toxicity
If not treated quickly and effectively, a toxic ingestion could have severe consequences, with 14% to 36% of patients potentially dying within hours of intake. However, if the situation is managed promptly and appropriately, the chances of recovery significantly improve. The treatment can gradually mend neurological, psychiatric, and liver function abnormalities, which typically return to normal following treatment.
Possible Complications When Diagnosed with Copper Toxicity
Swallowing copper may cause the formation of strictures, or narrowings, throughout your digestive system. It can also potentially cause immediate liver failure due to the toxicity of copper, which causes tissue death. It’s uncertain whether patients who ingest copper have a higher risk of liver cancer, but so far, no studies have linked copper ingestion to an increase in liver cancer.
Preventing Copper Toxicity
Reducing the availability of copper sulfate in stores and restricting its sale, distribution, and use to authorized personnel could help lower the occurrence of copper toxicity. A safer alternative could be to only sell copper sulfate in the form of large crystals. This is because most cases of poisoning happen when people accidentally or intentionally dissolve the powdery form of the compound.
Copper is a component of infant formula and is also found in breast milk. However, it’s noted that using a copper intrauterine device (IUD) doesn’t increase the copper levels in breast milk. Therefore, using a copper IUD is safe and won’t affect breastfeeding. It is seen as a breastfeeding-friendly method of contraception.
