Some metals – such as iron, magnesium, and copper – are required in small quantities for our bodies to function normally and remain healthy. Other metals, however, often referred to as heavy metals, are toxic to the body – even in small quantities. One of these toxic heavy metals is cadmium. Cadmium has no identified function in the human body and is known to be toxic when present at any level.

Sources of Cadmium Exposure 

Cadmium is present in the earth’s crust in very small quantities, which makes it difficult to avoid it completely, but in such small amounts it is generally harmless. Human activities such as making batteries, smelting metal, and recycling iron and steel scrap can increase cadmium levels in the local environment.

Burning fossil fuels and municipal garbage can also contribute to airborne cadmium levels. It is thus possible for environmental exposures of cadmium to occur from these localized sources. This is particularly true for populations living or working in the areas where these activities occur, potentially leading to harmful levels of exposure. 

Because the tobacco plant is especially good at accumulating cadmium from the environment, tobacco smoking can increase exposure to cadmium, which can affect both the smoker and those exposed to second-hand smoke. Smokers can have twice as much cadmium in their bodies as non-smokers.1

Much like mercury can accumulate in fish, environmental cadmium can build up in the food chain. Food is the primary source of cadmium exposure for non-smokers who don’t have occupational exposure.2

Mollusks, crustaceans, vegetables, rice, cereal grains, and starchy roots, tend to accumulate the most cadmium in the food supply. Although drinking water is not a common source of cadmium exposure, the levels in individual homes can vary depending on plumbing conditions.

Risks from Cadmium Exposure

Low background levels of naturally occurring cadmium in the environment do not tend to be harmful to humans. Cadmium will have different effects in the body depending on whether it gets into the body by breathing or by ingestion, whether the exposure amount is small or large, and whether the exposure lasts only a short time or over a long period. Most cadmium toxicity occurs from occupational exposures or tobacco smoking.

When exposure levels become toxic, the kidneys or lungs are often affected first, although many body systems can sustain damage. Cadmium exposure from the air can cause damage to the lungs, while cadmium that is ingested can cause damage in the kidneys.

Many environmental and health agencies, including the U.S. Environmental Protection Agency and the World Health Organization, have classified cadmium as a likely carcinogen.2

Testing for Cadmium 

Depending on the route of exposure, the quantity ingested, and the duration of exposure, cadmium toxicity can appear in many different organ systems, and it often resembles other diseases or disorders.

If you are concerned about possible cadmium exposure, especially if you are or were a smoker, or have occupational exposure, or live in a region with increased cadmium levels, then tests to determine cadmium’s presence in the body are available. 

Thorne’s at-home Heavy Metals Test tests for cadmium, as well as the heavy metals lead and mercury, and also the essential (good) minerals magnesium, selenium, zinc, and copper.


  1. [Accessed 4/4/18] 
  2. Exposure to cadmium: A major public health concern (WHO, 2010)
  3. [Accessed 4/4/18]