One of the most toxic metals on our planet is cadmium. It is one of the metals that is very common in the industrial workplace. Because of the low permissible exposure limits, overexposure from cadmium can occur for a long time. Cadmium occurs naturally in the environment. However, for industrial use, it is refined during the production of zinc. Unfortunately, once cadmium has been used in the industry, it is often discarded into the environment where it contaminates the soil, water, and air.

And is found in food Rice in Japan and … Those that eat a high carbohydrate diet are also at risk

Where is cadmium used?

Cadmium is heavily utilized in the electroplating industry, construction, painting, and shipyard industry. The highest risk of exposure occurs when paints containing cadmium are sprayed. Cadmium exposure may also occur when cadmium paint is removed by scraping or blasting. In addition, cadmium is also found in some batteries which if not properly disposed, the cadmium may leach into the soil and enter the food chain cycle.

Batteries; Nickel Cadmium and Cigarettes and near smelting plants AND Chemtails

History of cadmium

Nearly 50 years ago, there were no regulations on metals in the workplace. Thus, industrial exposure to cadmium was very high. Soon cadmium toxicity was reported all over the nation and by the 70s and 80s, limits on cadmium exposure were set in many industries. However, in developing countries, cadmium exposure still occurs because of lack of governmental policies. In the US, cadmium exposure occurs because some industries continue to disregard rules on safety and illegally dumping hazardous waste.

When cadmium is released into the environment it often forms aerosolized particles, which can be, transmitted long distances by the wind and rain. This cadmium may be inhaled or it may move into the soil and enter the food chain by being taken up by plants

Cadmium Concerns

Cadmium concentrations in drinking water are usually less than 1 ppb but in areas where cadmium has been dumped levels may be ten to fifty times higher. It is important to understand that there is no safe level of cadmium. Even very low levels of cadmium can and will slowly accumulate in the body and cause toxicity.

Today random sampling of the soil, air, and water in many parts of the country has shown much higher levels of cadmium than previously thought. Even outside the USA, cadmium exposure is a major concern. In Japan, people have been exposed to cadmium from contaminated water that was used to irrigate the rice fields.

For the average American, the most common source of cadmium exposure is food. Many studies show that cadmium is found in plants food. Further animals consume these foods and cadmium levels now appear in the liver and kidney of cattle, sheep, and swine. The daily intake of cadmium in the US does vary depending on where one lives but ranges anywhere from 8-30 micrograms. In the Orient, levels of 60-114 micrograms have been reported.

One other major source of cadmium that is always minimized is tobacco. Even though the actual amount of cadmium is low in tobacco; the important thing is that the cadmium goes directly into the lungs, from where it can easily be distributed to the blood stream.

Others at risk for cadmium toxicity include people who live near industrial waste sites or near factories that release cadmium into the air.

Another group that is also exposed to cadmium are artists and painters; many of the bright paints often contain high levels of cadmium. Artists also have a notorious habit of holding the paintbrush in their mouth and this way they can easily ingest cadmium particles.

Phosphate fertilizers 

In the last decade, it has come to attention that some phosphate fertilizers have also a high concentration of cadmium. 

In the USA, there are state and federal agencies that regularly monitor cadmium concentration in the air but sometimes these agencies become lax in their monitoring. Today, OSHA ensures that all industries follow the set permissible level of exposure rules to prevent toxicity.

Symptoms of acute exposure

Acute exposure to cadmium may lead to the following symptoms:

- Flu like symptoms

- Chills

- Muscle ache

- Anorexia

- Headache

- Weakness

- Fever

- Dizziness

These symptoms are often referred to as ‘cadmium blues’ and usually, occur within a few hours after the exposure. These symptoms resolve in 7-14 days as long as there is no damage to the airways. However, if the acute exposure is severe, then it may lead to pneumonitis, tracheobronchitis, and even pulmonary edema. This may result in vague chest pain, shortness of breath and decreased exercise tolerance.

If cadmium exposure continues then it can quickly lead to renal failure and severe damage to the liver.

Chronic exposure to cadmium

Cadmium can negatively affect every organ system in the body, including the central nervous system. Some of the effects of cadmium include the following:

1.     Elevation in blood pressure, which often requires medical therapy.

2.     Causes enlargement of the prostate gland and may lead to urinary incontinence.

3.     Lowers levels of testosterone and decreases libido.

4.     Cadmium has been linked to pancreatic cancer

5.     It may damage the kidney

Cadmium Effect on the Brain

Cadmium effects on the brain are very detrimental. Not only does it affect neurological function but it also impairs cognitive function at many levels. Cadmium causes neuronal death and alters the transmission of information. Individuals with cadmium toxicity may develop changes in behavior, loss of memory, poor concentration, difficulties in gait and muscle movement.

Prenatal Toxicity

Cadmium, when ingested by the pregnant mother can also harm the fetus. Since cadmium can cross the placenta is may lead to underweight babies and poor growth of the nervous system.

Cancer and Cadmium

There is now ample evidence showing that long-term exposure to cadmium can lead to cancers.

Cadmium and bone

Chronic exposure to cadmium can cause osteoporosis (bone thinning) and soft bones (osteomalacia). Fractures and bone pain eventually occur. In extreme cases of cadmium poisoning, just the mere body weight can lead to bone fractures.

Cadmium and the kidneys

The kidneys start to malfunction and are not able to remove waste material. The kidney dysfunction leads to muscle weakness, mental status changes, and extreme lethargy. Gouty attacks become common because of the accumulation of uric acid into the joints.

In addition, there are electrolyte imbalances that can occur with real failure such as high potassium levels that in turn can cause irregular rhythms of the heart. Cadmium exposure is also associated with development of kidney stones

People exposed to cadmium often lose their ability to smell and taste.

How does cadmium act?

It is believed that cadmium acts as a catalyst for the formation of reactive oxygen species. It enhances lipid peroxidation and damage to cell membranes. The metal also causes depletion of antioxidants like glutathione and other protein-bound sulfhydryl groups. Laboratory research also reveals that cadmium promotes the inflammatory reaction by production of cytokines

Measuring cadmium

Today there are several methods of measuring cadmium in the body. While levels of cadmium can be measured, not many laboratories have the right equipment. Other means to assess cadmium exposure is by measurement of biochemical markers like urinary beta 2 microglobulin, which is a good indicator of kidney damage.

In some industries, there is regular measurement of blood or urine cadmium to ensure that the worker is not getting over exposed to this metal

In general, a healthy person should not have cadmium levels of more than 1 microgram/L in either urine or blood. If the levels of cadmium are more than 5 micrograms/L, than exposure to cadmium has occurred. Levels of 25-50 micrograms/liter are often associated with kidney damage and less more than 1,000 micrograms/liter are associated with acute poisoning and can be fatal.

Protection against cadmium

The best way to protect the body is to frequently get cadmium levels measured. If you suspect cadmium in your air, water or food, you need to get the levels measured by a registered laboratory. Thoroughly wash all your vegetables and fruits before consumption and only buy your meat and seafood from reputable grocery stores. If the levels in your body are high, you may need long term detox program.

When working with cadmium it is important to wear a mask as one of the chief method of  exposure occurs is via inhalation of aerosolized particles.

References: 

Nemmiche S. Oxidative Signaling Response to Cadmium Exposure.  Toxicol Sci. 2016 Nov 1.

Nigra AE, Ruiz-Hernandez A, Redon J, Navas-Acien A, Tellez-Plaza M.  Environmental Metals and Cardiovascular Disease in Adults: A Systematic  Review Beyond Lead and Cadmium .  Curr Environ Health Rep. 2016 Dec;3(4):416-433.

Chunhabundit R. Cadmium Exposure and Potential Health Risk from Foods in Contaminated Area, Thailand.  Toxicol Res. 2016 Jan;32(1):65-72.