What is Chromium Toxicity?
Chromium is a common element found in nature and is notably the seventh most plentiful element on Earth. It can exist in various forms, but the most stable ones are trivalent chromium and hexavalent chromium. Chromium can also occur as chromium metal. Interestingly, hexavalent chromium is more water-soluble than trivalent chromium and a hundred times more toxic.
The dangers of prolonged exposure to chromate, a form of chromium, have been well-recognized for over 200 years. During World War II, there was a noted increase in the risk of lung cancer among those exposed to hexavalent chromium.
During the 1980s, hexavalent chromium was a subject of concern due to its contamination of groundwater. This led to widespread public exposure and caused significant property damage, costing millions of dollars.
Because of the profound health risks it poses, chromium is strictly regulated. It’s considered a “known” or “likely” cause of cancer in humans, placing it in the same high-risk category as arsenic, cadmium, lead, and mercury.
What Causes Chromium Toxicity?
Chromium is a metal known for its shiny appearance and resistance to rusting; it’s often used in making steel. Two versions of it, known as trivalent and hexavalent chromium, are utilized in numerous industries like oil refining, metal processing, leather tanning, dye making, and concrete production. They’re also found in bullets, farming fertilizers, and wood preservatives. Everyday exposure to chromium happens mostly through eating food and drinking water that are contaminated or using tobacco products that release chromium when they’re burned.
In the past, there was worry concerning potential chromium poisoning due to the use of chromium-cobalt components in metal-on-metal hip replacements. However, the symptoms didn’t line up with the levels of chromium in the blood, and more recent findings indicate that the observed poisoning is more likely linked to exposure to cobalt. The design of these components has been improved recently, lessening worries about modern medical devices.
It’s important to note that not all contact with chromium is harmful. Since the 1950s, trivalent chromium has been considered a necessary nutrient, playing a role in the way the body manages glucose and lipids, and having a recommended daily intake of 120 micrograms. Furthermore, it’s present in several dietary supplements marketed for weight loss and blood sugar regulation. Nevertheless, recent studies have questioned the importance of trivalent chromium; there’s evidence to suggest that compounds containing it might be toxic and cause cancer.
Despite this, supplements containing chromium, especially chromium picolinate and chromium chloride, are increasingly popular. They jumped from being the fourth most sold vitamin and mineral supplements in 2016 to the second most sold in 2021.
Risk Factors and Frequency for Chromium Toxicity
Chromium is a naturally occurring element found everywhere, from volcanoes, rocks, and animals to plants, soil, and water. The amount of chromium in these natural environments can vary. For instance, uncontaminated water typically contains between 1 to 10 μg/L of chromium. Air in rural and residential areas can have chromium contents ranging from 0.2 to 9 ng/m3, and possibly higher in urban areas. Chromium is also found in many types of food, particularly meat, fish, fruits, and vegetables.
Besides natural sources, chromium is also produced through industrial processes. More than 16.4 million tons of chromium are produced each year globally, with over 170,000 tons produced in the United States. A portion of this chromium ends up being released into the environment, leading to increased levels in the air, water, and soil.
To regulate the levels of chromium, agencies like the United States Environmental Protection Agency (EPA) and the World Health Organization have set safety standards. The EPA, for example, has a water safety standard of 0.1 mg/L or 100 ppb for total chromium. The World Health Organization is stricter, recommending no more than 0.05 mg/L or 50 ppb of a type of chromium known as Cr(VI) in drinking water.
Many people are exposed to chromium in their workplaces, particularly in occupations involving welding, construction, and cement work. This exposure can be linked to health risks, including cancer. As a result, several government agencies around the world have set standards for acceptable levels of chromium exposure in the workplace.
- Naturally, chromium can be found in areas such as volcanic emissions, rocks, animals, plants, soil, and water.
- The concentration of chromium varies, with 1 to 10 μg/L in uncontaminated water and 0.2 to 9 ng/m3 in the air of rural and residential areas.
- Every year, industrial processes globally produce over 16.4 million tons of chromium.
- Some of this chromium ends up in the environment, leading to increased levels in the air, water, and soil.
- The EPA and the World Health Organization have set safety standards for chromium.
- Many workers around the world are exposed to chromium in their workplaces, which can pose health risks, including cancer.
- Due to these risks, government agencies have set standards for acceptable levels of chromium exposure in the workplace.
Signs and Symptoms of Chromium Toxicity
Acute chromium toxicity is typically seen in people who have been exposed to it at work. Therefore, understanding a person’s job history is key. People who work in industries like welding, petroleum refining, mining and ore processing, leather tanning, dye and pigment production, construction, law enforcement or military, or agriculture are particularly at risk.
During a medical evaluation, it’s helpful to know where and how the person was exposed to chromium. Information on the air ventilation in the room, the kind of respiratory protection used, the circumstances of exposure, and any cleaning up before medical attention can be important. Acute toxicity that happens due to contact with the skin might result in things like chemical burns, blisters, sores, tissue death, or skin sloughing. The severity of these symptoms can depend on factors such as the level of contamination, concentration of the compound, duration of exposure, and the level of personal protective equipment worn.
Chromium (VI) is often suspected when someone has come into contact with a brightly colored solid or reddish fluid as many Chromium (VI) compounds are pigments. A Safety Data Sheet (SDS) can help identify if certain dangerous compounds like chromic acid, sodium chromate, calcium chromate, potassium chromate, potassium dichromate, or ammonium dichromate might be present in the chemical exposure and at what concentration. Chronic skin toxicity is more likely to appear as hypersensitivity symptoms like contact dermatitis, skin ulcerations, eczema, skin thickening, and eye inflammation.
In many workplaces, inhalation toxicity might be less common due to safety controls enforced by organizations like OSHA, NIOSH, and WHO meant to limit occupational exposures. However, conditions such as lung inflammation and respiratory irritation can occur from acute exposure, and symptoms might include coughing, difficulty breathing, runny nose, wheezing, choking, and flare-ups of asthma.
Long-term or constant inhalation exposures are known to result in nasal ulcers, holes in the nasal septum, and bleeding from the nose along with occupational asthma and inflammation of the nose. This might increase the person’s risk for squamous cell lung cancer due to continued tissue damage. Non-respiratory problems associated with inhaling Chromium (VI) might include stomach ulcers, inflammation of the stomach lining or colon, dizziness, headaches, weakness, abnormal sperm count and movement. There have also been reports of vitamin B12 and folate deficiencies, although it’s not fully understood why this happens.
Ingesting Chromium (VI) may lead to symptoms like mucosal burns, water in the lungs, gastrointestinal bleeding, ulcers, inflamed stomach lining, indigestion, anemia, elevated white blood cell count, and bronchitis at larger doses due to accidental or intentional ingestion. Although, it’s more likely for someone to not show symptoms or only show mild symptoms at the lower levels of exposure typical in workplaces because of detoxification by gastric juice.
Acute toxicity due to Chromium (III) ingestion is not likely because it doesn’t get absorbed well by the body. It can however reduce iron absorption and cause symptoms of anemia and breakdown of muscle tissue at high doses. People might report taking chromium supplements for weight loss or blood sugar control; these supplements contain chromium picolinate or chromium chloride, which are forms of trivalent chromium.
Liver damage due to ingestion might result in jaundice, elevated bilirubin in the blood, increased lactate dehydrogenase, and liver inflammation. Kidney damage might result in sudden kidney failure, protein or blood in the urine, or absence of urine with both Chromium (III) and Chromium (VI) toxicity; as the kidneys are the primary organs that excrete chromium compounds. Chronic ingestion toxicity might be linked to liver and stomach cancer. Other cancers associated with chromium toxicity include those of the larynx, bladder, kidney, lymph node, blood, pancreas, thyroid, bone, and testes.
Testing for Chromium Toxicity
Whole blood, plasma, and urinary chromium levels can all be tested, but these tests might not be easily accessible and may not be as beneficial for managing acute toxicity. However, they could still be useful in identifying and managing long-term exposure to chromium in the workplace. Usual levels of chromium in blood and plasma range between 0.10 mcg/L and 0.16 mcg/L, while the average chromium level in urine is around 0.22 mcg/L.
As for detecting acute and chronic chromium poisoning, the chromium (Cr III) that has been absorbed into the body takes approximately 40 hours to decrease by half and about a week to reduce by 95%. On the other hand, chromium (Cr VI) takes about 30 days to decrease by half and around 130 days to reduce by 95%. This is because it gets stored in our red blood cells, slowly released as these cells die and are replaced.
Treatment Options for Chromium Toxicity
If a person comes into contact with a high dose of chromium, some immediate actions can help. If possible, remove the person from the source of the chromium to provide them with clean, fresh air. Other treatments can help with experiencing difficulty breathing by providing humidified supplemental oxygen, support for breathing, and medications to help open up the airways and clear mucus from the lungs.
If a person swallowed the toxic substance, it’s important not to induce vomiting or consume substances that can neutralize stomach acidity, like bicarbonate or antacids. Instead, orally taking ascorbic acid (vitamin C) or undergoing a procedure that cleans out the stomach (gastric lavage) can be helpful.
If chromium has come in contact with the skin or eyes, the area should be cleaned thoroughly. A substance called calcium disodium edetate (EDTA) can be applied, which helps bind the chromium and prevent it from entering the body.
In order to remove chromium from the body, a few treatments might be considered. This includes a process where blood is purified outside of the body (hemodialysis), as well as the use of substances like ascorbic acid (vitamin C), N-acetylcysteine, and calcium EDTA. Hemodialysis can be particularly beneficial when a person has experienced substantial chromium exposure to guarantee rapid and effective removal.
It’s also important to note that some substances might have a defensive effect against the harmful consequences of chromium exposure based on animal studies. These substances, which are primarily antioxidants, include selenium, vitamin E, zinc, and melatonin. However, there is not enough evidence from human studies to say for sure whether taking larger doses of antioxidants can reduce chromium’s adverse effects.
Despite this, people who regularly come into contact with chromium at work are encouraged to consume foods rich in vitamin C, vitamin E, vitamin B6, folic acid, selenium, and zinc to reduce oxidative stress – which is an imbalance between free radicals and antioxidants in your body – and lessen the effects of exposure to certain forms of chromium.
What else can Chromium Toxicity be?
When trying to identify chromium poisoning, it’s important to know that the patient could be exposed to it through their job. This is because chromium can impact many areas of the body, and its symptoms are quite general. In other words, a lot of other substances found in workplaces can lead to similar symptoms. Some examples include exposure to other acids which can result in burns on the skin, or exposure to ultraviolet light which can harm the eyes, especially in those who do welding. Certain conditions like eczema and asthma, which can be made worse by a wide range of triggers, might seemingly occur for no apparent reason. Symptoms like increased secretions from the respiratory tract, vomiting, diarrhea, wheezing, and narrowed airways can be a sign of cholinergic toxicity. A bloody nose and hole in the nasal septum might be caused by a number of nose irritants. Feeling dizzy, weak, or generally unwell could be due to breathing volatile substances or certain kinds of liquids. Other heavy metals like mercury, lead, cadmium, and arsenic are known to cause damage by generating harmful molecules in the body, increasing the chances of genetic mutations and cancer.
If symptoms vary throughout the day or week and especially correspond to work days, a doctor should seriously consider the possibility of chromium toxicity. Even hobbies can expose people to harmful amounts of chromium – activities that use chromium-containing materials probably should be examined more closely.
The symptoms of chronic chromium toxicity are more subtle but serious. When diagnosing any new cancer, the doctor should ask detailed questions about the patient’s job, particularly when considering common cancers that can be caused by chromium exposure like squamous cell carcinoma in the lungs, and cancers in the stomach and liver. People who take excessive chromium supplements should be considered at risk for developing stomach ulcers, liver damage, or anemia.
What to expect with Chromium Toxicity
The outlook for acute chromium poisoning is usually very good, with fatalities mainly observed after very large amount has been swallowed. However, long-term exposure to chromium can lead to undetected cancerous lesions, which might not show symptoms until the disease has advanced significantly. A study suggested the overall mortality due to lung cancer may be 6 in 1,000 workers exposed to a level of chromium at 1 mcg/m3. To catch this early, healthcare providers should maintain a high level of suspicion and meticulously look at the patient’s work history for potential exposure, which may lead to early detection and a better chance of recovery.
Possible Complications When Diagnosed with Chromium Toxicity
Long-lasting side effects of burns, whether on the skin or the mucosa (the inside lining of the body), can include scarring. Coming into contact with or breathing in toxic substances can lead to skin sensitization and asthma. Additionally, if toxic substances affect the digestive system, this can lead to reduced absorption of nutrients and vitamins. Other serious risks include developing anemia, ongoing liver or kidney disease, and an increased lifelong risk of developing cancer.
Potential Long-term Complications:
- Scarring from skin and mucosal burns
- Dermal sensitization
- Asthma due to exposure to toxic substances
- Decreased nutrient and vitamin absorption
- Increased risk of anemia
- Chronic liver disease
- Chronic kidney disease
- Lifetime increased risk of cancer
Preventing Chromium Toxicity
To prevent harmful exposure in work settings, care is taken through several steps which include:
– Installing proper ventilation systems
– Implementing rules limiting the duration of exposure
– Restricting access to areas where chromium is used
– Providing workers with protective gear like gloves, gowns, and masks.
Employees exposed to chromium should be made aware of its long-term effects and ways to spot early signs of complications. Furthermore, people who take chromium supplements should be informed about the pros and cons of such supplements. They should also be advised about possible side effects and the importance of following the instructions provided by the manufacturer to avoid taking too much.
