Cadmium poisoning: causes and symptoms

Medically reviewed by Neka Miller, PhD on January 21, 2021. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Cadmium is a toxic heavy metal that serves no health-supporting function when present in the body. While cadmium intake in small amounts has negligible effects and doesn’t result in any noticeable symptoms, moderate to high amounts of cadmium—which can be revealed through heavy metal testing—can cause some severe health issues. Keep reading to discover more about the causes and symptoms of cadmium poisoning below.

What is cadmium?

Cadmium is a metal that appears soft, malleable, and bluish-white in its elemental form. While it is a relatively widespread element, it is rarely found on its own as a pure metal and more often forms complex compounds in zinc ores. It is mainly produced through the process of smelting, mining, and refining zinc, lead, and copper.

While it found initial use as a dye for producing shades of yellow, orange, and red, cadmium today is most widely used in nickel-cadmium rechargeable batteries. It is also found in:

• Plating on iron and steel products
• Plastic stabilizers
• Alloy elements for lead, copper, and tin
• Cigarette smoke

Along with its status as an industrial byproduct, cadmium is a natural component of the earth’s crust and mantle and can easily enter the atmosphere, water, and soil. This can happen through volcanic activity, weathering of sediment, and the burning of fossil fuels. This can lead to cadmium’s presence in sources of drinking water and food, including vegetables, fish, and animals.

What causes cadmium poisoning?

Cadmium poisoning is caused by high concentrations of cadmium accumulating in your body. Ingested cadmium is usually stored in the liver, kidneys, and bones. Eliminating cadmium absorption naturally is a slow process, and cadmium can last for decades in the human body.

One of the main causes of cadmium toxicity in the United States is cigarette smoke. The chemicals within cigarettes contain cadmium, and smokers are believed to ingest twice the daily amount of cadmium as non-smokers. People breathing in secondhand smoke also take in a higher amount of cadmium, as this is a form of environmental exposure.

For the majority of the non-smoking population, cadmium poisoning comes from food. Sudden high levels of cadmium in soil can cause some crops to uptake the heavy metal. The rate of cadmium absorption depends on a whole host of factors, like the crop species, the quality of the soil (pH and salinity), and the presence of other elements. Proximity to certain industrial plants, particularly those involving construction and manufacturing, can also affect soil and sources of water for crops.

Cadmium poisoning can also occur in certain workplaces where cadmium is either used in the process or generated as a byproduct. By means of occupational exposure, workers can be exposed to high cadmium levels and experience its toxic effects over time while smelting and mining for other metals. The risk of cadmium poisoning is particularly high in workplaces manufacturing batteries, plastic, coatings, and solar panels. Other jobs that are associated with the occupational exposure of cadmium include:

• Electroplating
• Welding
• Metal machining
• Landfill operations
• Recycling of electronic parts or plastics
• Composting and general waste collection (from dust or incinerating municipal waste)

Check for your body’s cadmium levels from the convenience of home with the at-home Heavy Metals Test. This test measures 4 toxic chemicals that can put your health at risk (including cadmium), and 2 trace minerals your body needs to function at its best.

Symptoms of cadmium poisoning

Cadmium toxicity can affect major aspects of one’s health, though more studies are necessary to fully assess the potential risk to humans and the environment. The general symptoms for acute cadmium poisoning include:

• Nausea and vomiting
• Diarrhea
• Abdominal pain
• Flu-like symptoms

Respiratory health

When inhaled consistently over time, cadmium may affect your lungs and breathing. Many studies associate chronic occupational inhalation of cadmium dust and cadmium fumes with an increased risk of respiratory problems, including:

• Chronic obstructive pulmonary disease (COPD), which describes a group of lung diseases that can make breathing difficult
• Emphysema, characterized by damage to air sacs within the lungs
• Bronchitis, an inflammation of the bronchial tubes that carry oxygen to the lungs
• Chronic rhinitis, an inflammation of the mucus membranes in the nose
• Damage to the olfactory epithelium

Cadmium is also classified as a probable carcinogenic (cancer-causing) agent when inhaled. This suggests that chronic cadmium exposure through inhalation may contribute to lung cancer.

Kidney damage

The kidneys bear the brunt of the damage from chronic cadmium exposure, both via ingestion and inhalation. This is because the kidneys act as a filtration system, removing waste and excess fluid from the body. It can take up to 10 years of regular and consistent exposure for cadmium levels to build up enough to result in kidney damage, but animal studies have suggested some subtle changes to renal function even after acute exposure to cadmium.

Most commonly, regular cadmium exposure has been linked to progressive renal tubular dysfunction. Some studies suggest that even at lower concentrations, cadmium intake can have some severe effects on the kidneys and general renal function. At high concentrations, chronic cadmium poisoning may even cause renal failure. Kidney stones are also more common in populations experiencing excessive cadmium exposure.

Bones and skeletal health

Cadmium compounds can also accumulate in the bones. However, bone diseases and skeletal health issues more often come as a side effect of renal issues as any damage to the kidneys may cause changes in how calcium and vitamin D are metabolized and absorbed.

Severe chronic cadmium poisoning can contribute to bone lesions in later stages. This can eventually lead to osteoporosis (brittle, porous bones) and osteomalacia (a significant softening of bones), which can contribute to certain types of fractures and other effects.

Itai-itai disease

Originally discovered in Japan’s Toyama Prefecture from 1910 to the 1960s, Itai-itai disease came about when slag from a mine contaminated the Jinzu River with high levels of cadmium. The contaminated river water heavily polluted nearby rice paddies, leading to high cadmium concentrations in the rice and surrounding soil.

Symptoms of Itai-itai disease varied and included:

• Severe renal dysfunction
• Severe osteoporosis and osteomalacia
• Low blood pressure
• Normochromic anemia (an inadequate amount of red blood cells in the body)

Diagnosing and treating cadmium poisoning

The diagnostic process for cadmium poisoning generally involves tests that determine the levels of cadmium concentration in blood, hair, nails, saliva, and/or urine. As the kidneys are the main organ affected by cadmium poisoning, urine tests play an important role in determining a diagnosis. Specific tests can determine urinary cadmium levels, as well as increased levels of protein in your urine (proteinuria), which is one of the more common heavy metal poisoning symptoms.

Once diagnosed, the dangerous effects of cadmium poisoning can be minimized by avoiding or removing the source of exposure as quickly as possible and ensuring the affected person is informed of ways to lessen the risk of exposure in the future. Additionally, some supplements—like vitamin D and/or calcium—may be helpful for symptom relief if the person is experiencing bone-related issues.

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References

1. Toxic Substances Portal: Cadmium. Centers for Disease Control and Prevention. URL. Accessed January 21, 2021.

2. Cadmium Factsheet. Centers for Disease Control and Prevention. URL. Accessed January 21, 2021.

3. Agency for Toxic Substances and Disease Registry Case Studies in Environmental Medicine (CSEM) Cadmium Toxicity. Centers for Disease Control and Prevention. URL (PDF). Accessed January 21, 2021.