Cadmium is a natural element of the earth's crust. It is usually found as an inorganic element in combination with other elements, such as oxygen (Cadmium oxide), chlorine (Cadmium chloride), or sulfur (Cadmium sulfate and sulfide). All soils, rocks, coal, and fertilizers contain Cadmium. Most Cadmium is exported while producing metals such as Zinc, Lead, Copper, and others. Cadmium is not easily oxidized and has many uses, including batteries, paints, metallic coatings, and plastics.
Exposure to Cadmium occurs mainly in the workplace, where various Cadmium products are manufactured. The general population is exposed by inhaling cigarette smoke or eating cadmium-contaminated foods. Cadmium damages the kidneys, lungs, and bones. Most of the toxic metals (Mercury, Lead, Cadmium, and Arsenic) humans encounter are natural constituents of the earth's crust. Still, the increase in air, water, and soil is mainly due to industrial demand and energy production (pollution).
How does Cadmium enter the environment?
- Cadmium enters the soil, water, and air from mining, industry, burning coal, and household waste.
- Cadmium is not degraded in the environment but can change forms.
- Cadmium particles in the air can travel long distances before falling to the ground or water.
- Some forms of Cadmium dissolve in water.
- Cadmium is firmly bonded to soil particles.
- Fish, plants, and animals take Cadmium from the environment.
How is one exposed to Cadmium?
- Eating foods containing Cadmium. All foods have low levels of Cadmium (the highest levels are in shellfish and the liver and kidneys of animals).
- By smoking cigarettes or by inhaling cigarette smoke.
- Breathing contaminated air in the workplace.
- Drinking contaminated water.
- Living near industrial installations that release Cadmium into the air.
How Can Cadmium Affect Health?
Inhalation of high concentrations of Cadmium can severely damage the lungs. Consuming food or drinking water with very high levels of Cadmium strongly irritates the stomach, leading to vomiting and diarrhea.
Long-term exposure to lower levels of Cadmium in the air, food, or water leads to the accumulation of Cadmium in the kidneys and possible kidney disease. Other long-term effects are damage to the lungs and the creation of fragile bones.
Cadmium and its compounds are known to be carcinogenic to humans.
How can the risk of exposure to Cadmium be reduced?
At home, Cadamium-containing substances and Nickel-cadmium batteries should be kept out of the reach of small children.
Cadmium is a component of cigarette smoke. Avoid smoking indoors, such as in the car, to limit exposure.
If you are exposed to Cadmium at your workplace, use all safety precautions to prevent Cadmium-containing dust from being transported home on your clothing, skin, hair, or tools.
A balanced diet can reduce the amount of Cadmium from foods and beverages.
How can one determine if one has been exposed to Cadmium?
Cadmium can be measured in blood, urine, hair, or nails. The concentration of Cadmium in urine has been shown to reflect the amount of Cadmium in the body accurately. Cadmium concentration in the blood reflects recent exposure to Cadmium, while the concentration of Cadmium in urine indicates both recent and past exposure.
We can measure Cadmium levels in the blood and most biological materials.
Determination of metals is done by ICP-MS (Inductively Coupled Plasma Mass Spectrometry), a method that enables the simultaneous detection of many metals. Its sensitivity and accuracy are significantly better than conventional atomic absorption, with the ability to measure metals at concentrations up to 1 in 1015 (1 in 1 quadrillion, ppq)!
More information on Cadmium toxicity
Cadmium concentration is 2-3 times higher in eye lenses with cataracts than in eye lenses without cataracts of the same age. This is probably because cadmium displaces zinc from the active sites of the enzymes by binding it to sulfhydryl groups, thereby deactivating protective enzymes that remove free radicals and possibly other protective/repairing mechanisms.
Heavy metals, such as Cadmium, Mercury, Gold, and Lead, are known to be nephrotoxic at high concentrations. Cadmium is of particular concern because of its extended duration in the kidneys. Therefore, in addition to urine level testing to document Cadmium toxicity, biomarkers of renal function should also be evaluated. Early markers of kidney damage due to Cadmium include laboratory evaluation of proteinuria, glucosuria, aminoaciduria, hypercalciuria, and polyuria. A sensitive marker for advanced renal tubular damage due to Cadmium is the low molecular weight beta-2-microglobulin protein in the urine. Cadmium has also been shown to increase the incidence of kidney stones significantly.
The chelating agent Ca-EDTA has been used intravenously for many years as a therapeutic agent of choice for patients with high levels of Lead in the blood. This factor also effectively increases the urinary excretion of Iron, Copper, Nickel, Cadmium, and Manganese. However, Ca-EDTA also has a high affinity for Zinc; if not used properly, it can cause Zinc deficiency.
Several toxic minerals, including Mercury, Lead, Thallium, and Cadmium, are normally or partially excreted in the bile. Therefore, under certain conditions, analyzing feces for metals without chelating agents (challenge) may provide at least qualitative information on the rate of bile excretion of metals by the body. However, contaminated foods are an important source of exposure to heavy metals, and metals not absorbed by the gastrointestinal tract can contribute a significant proportion to the total amount of metals measured in the fecal sample.
One category of toxic chemicals that can cause severe damage to health and that can mimic other disorders, especially in children, is heavy metals. Lead, Mercury, Arsenic, Aluminum, and Cadmium are well-documented examples. Long-term exposure to these metals often results in accumulation in specific organs, thereby impairing the normal functioning of the organ. Also, many toxins are now known to exert toxic activity at levels far below what was initially supposed. For example, Cadmium can mimic the effect of estrogen on tissues at deficient levels (0.00001 ppb - parts per billion).
Toxic metals act as "chemical antagonists" with trace minerals that are chemically and physically similar (e.g., Cadmium competes with Zinc, Lead competes with Calcium, and Mercury competes with Selenium). This phenomenon can lead to high rates of loss of the competing trace minerals or the inhibition (or over-activation) of trace element-dependent physiological systems, such as enzymes.
One of the most essential detoxification systems in all organisms, from bacteria to humans, depends on producing a family of four proteins known as metallothionein (MT). Metallothioneins are extremely unusual proteins comprising about 30% cysteine and are responsible for storing, transporting, and removing intracellular metal ions. The primary role of metallothionein in the absence of toxic metals is the transport and short-term storage of Zinc and Copper. Metallothioneins are known to effectively bind many toxic metals (particularly Cadmium and Mercury) and act as transporters of the toxic metal to the liver or kidneys, completed by its coupling to glutathione and subsequent metal secretion. Metallothioneins form high-affinity complexes with several metals; they can prevent toxic heavy metals from reacting with other biomolecules or acting as catalysts, weakening their toxicity.
Dietary adequacy significantly affects the absorption, retention, toxicity, and excretion of toxic metals. Lead and Cadmium absorption is increased in situations of Iron or Calcium deficiency. In addition, Iron deficiency is one of the many factors that lead to increased intestinal permeability.
Exposure of the body to heavy metals (Lead, Mercury, Cadmium, Arsenic, Nickel, and Aluminum), as well as to solvents (formaldehyde, toluene, benzene), pesticides, and herbicides, may result in the accumulation of these molecules. As a result, several psychological and neurological symptoms can occur:
- Depression
- Headaches
- Confusion
- Psychiatric diseases
- Numbness of limbs
- Abnormal reflexes
- Other signs of nervous system dysfunction
Heavy metals, such as Lead, Mercury, Cadmium, and Aluminum, can cause seizures by disrupting neural function. Heavy metal toxicity should be considered as a possible cause of all seizures.
Exposure to food additives, solvents (formaldehyde, toluene, benzene), pesticides, heavy metals (Lead, Mercury, Cadmium, Arsenic, Nickel, Aluminum), can have major effects on detoxification, a condition known as "impaired liver detoxification".
Sperm is also particularly susceptible to the harmful effects of heavy metals such as Lead, Cadmium, Arsenic, and Mercury.
Important Note
Laboratory test results are the most critical parameter for diagnosing and monitoring all pathological conditions. 70% and 80% of diagnostic decisions are based on laboratory tests. Correctly interpreting laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted solely based on the numerical result of a single analysis. They should be interpreted concerning each case, family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
