Health Effects of Cadmium

Health Effects of Cadmium

 

Cadmium is a metal found on the Earth's surface and is usually found with zinc, lead, and copper. This metal is silver-white, soft, and toxic. Cadmium is used as a coating material to prevent corrosion and is also used in batteries and pigments. However, cadmium mainly comes as a by-product from the production of zinc, lead, and copper. Cadmium and its compounds are known to be carcinogenic, meaning they can cause cancer. The International Agency for Research on Cancer (IARC), which is part of the World Health Organization, classifies these substances as Group 1, indicating they can cause cancer in humans.

< Overview of exposure sources, pathways and health effects associated with cadmium (1)>

 

■  Cadmium Exposure in the Workplace

Cadmium is primarily used in batteries, especially nickel-cadmium batteries. It is also used in paints, plastics, ceramics, glass as pigments and in plastics as stabilizers, as well as in plating and alloys. Occupational exposure to cadmium can occur in zinc or lead mines, during the production or handling of cadmium powder, or while welding or alloying metals treated with cadmium. Additionally, exposure can occur in the workplace if someone handles materials containing cadmium and then eats food or smokes cigarettes without washing their hands properly.

 

■   Cadmium Exposure in the Environment

In general population, people are exposed to cadmium through their diet. In particular, cadmium tends to accumulate in plants and aquatic life such as fish that have grown in soil or water contaminated near metal mines, smelters, or areas affected by industrial wastewater. Smoking is also a significant source of chronic cadmium exposure. "Itai-itai disease" is one of the most well-known pollution-related diseases, caused by cadmium from a zinc mine in Japan. This led to chronic cadmium poisoning among local residents, causing weak bones and symptoms like proteinuria and diabetes.

 

■   Itai-itai disease

Since the late 1910s, residents of Toyama Prefecture in Japan began visiting hospitals with complaints of pain in the joints of their backs, arms, and legs, but the cause remained unidentified for 50 years. On May 8, 1968, the Japanese government officially announced that the issue was due to cadmium poisoning, which caused calcium in the bones to dissolve, leading to kidney problems and softening of the bones, a condition known as Itai-itai disease. Investigations revealed that from 1945, cadmium contained in waste ore discharged from the Mitsui Mining & Smelting Company in the upper reaches of the Jinzu River contaminated the river, affecting crops, shellfish, and water sources. This led to the outbreak of Itai-itai disease. The primary symptoms of the disease manifest in the bones, as cadmium is absorbed into the bones, inhibiting calcium absorption and thus weakening the bones. Patients primarily complained of severe pain in the spine and legs (2).

 

■   Health Effects of Cadmium Exposure

The toxicity caused by cadmium is differentiated into acute and chronic types.

 

(1) Acute toxicity

Inhaling high concentrations of cadmium fumes can lead to symptoms similar to metal fume fever. These include inflammation of the nose and throat, coughing, headaches, dizziness, weakness, chills, fever, chest pain, and difficulty breathing. A few days later, this can develop into acute pneumonitis accompanied by pulmonary edema, which can progress to respiratory failure and even death. Consuming large amounts of cadmium compounds can cause symptoms such as nausea, vomiting, headaches, abdominal pain, liver damage, and acute kidney failure.

 

(2) Chronic toxicity

Long-term exposure to cadmium can lead to chronic respiratory diseases, kidney disorders, and bone issues, and it can also affect the cardiovascular system. The symptoms of chronic toxicity vary depending on the route of exposure. For example, occupational exposure to cadmium more commonly results in respiratory and kidney problems, while exposure through diet is more likely to cause kidney and bone issues. Chronic respiratory conditions caused by cadmium include chronic bronchitis and chronic obstructive pulmonary disease (COPD). Chronic kidney disease manifests as a decline in tubule and glomerular function, which can progress to Fanconi syndrome. Bone issues may include osteomalacia, kidney stones, and pathological fractures. Additionally, cadmium can increase the risk of developing lung and prostate cancer.

 

 

■   Reference values (Urinary Cadmium)

HBM I : 0.5 µg/L (Children and adolescents), 1 µg/L(Adults) (3)

HBM II : 2 µg/L (Children and adolescents), 4 µg/L(Adults) (3)

 

 

 

■   References

The content is primarily based on Casarett and Doull’s Toxicology 9th edition and Cadmium -Policy Brief (https://www.hbm4eu.eu/wp-content/uploads/2022/07/HBM4EU_Policy-Brief-Cadmium.pdf).

(1)   Cadmium -Policy Brief. https://www.hbm4eu.eu/wp-content/uploads/2022/07/HBM4EU_Policy-Brief-Cadmium.pdf. Access date: 2024-03-01

(2)   Itai-itai disease: https://en.wikipedia.org/wiki/Itai-itai_disease. Access date: 2024-03-01

(3)   Human biomonitoring (HBM) values derived by the Human Biomonitoring Commission of the German Environment Agency, status june 2023: https://www.umweltbundesamt.de/sites/default/files/medien/4031/bilder/dateien/kopie_von_hbm-werte_engl._stand_sept._2023.pdf. Access date: 2024-03-01