Chromium: health effects
Chromium is a naturally occurring element. Some forms of chromium are essential for the human body to function while other forms are toxic to humans.
Exposure to toxic forms of chromium can occur in some work environments and sometimes in the general population due to contamination of our environment.
What is chromium?
Chromium (chemical symbol Cr) is a naturally occurring element found in rocks, soil, water, plants, and animals. Chemically, chromium can form what is known as different oxidation states (different forms) – it is these states that determine how toxic chromium is. Chromium has oxidation states ranging from chromium II to chromium VI. The most abundant forms of chromium in the environment are trivalent chromium (chromium III) and hexavalent chromium (chromium VI). The effects of exposure to humans depends on what form of chromium a person is exposed to, how much a person has been exposed to and whether it was inhaled, swallowed or contacted the skin.
What is trivalent chromium (chromium III)?
Trivalent chromium (chromium III) is the most chemically stable form of chromium and it is the most common natural form found in the earth’s crust. It is also an essential nutrient for normal function of the human body as it helps regulate how your body processes fats and sugars.
How can trivalent chromium affect my health?
What if I don’t get enough trivalent chromium?
Trivalent chromium plays a role in regulating sugar and fat metabolism, but it is not clear how it does this. Trivalent chromium deficiency is extremely rare and has only been reported in hospital patients unable to eat and who receive intravenous nutrition over a long period of time.
What if I get too much trivalent chromium?
Trivalent chromium has low toxicity, meaning it is not very harmful to your body. It does not get absorbed through the gastrointestinal tract or digestion very well and it has been shown that taking dietary supplements containing trivalent chromium is generally not associated with adverse effects.
However, poisoning with trivalent chromium can occur, although it is rare. If this occurs seek medical advice or call the Poisons Information Hotline on 13 11 26.
What is hexavalent chromium (chromium VI)?
Hexavalent chromium, (chromium VI) rarely occurs naturally, and is mostly produced and released into the environment by human activities. Hexavalent chromium can be an impurity in Portland cement and in tattoo inks. It can also be generated in industrial processes involving stainless steel (casting, welding, and cutting). Hexavalent chromium compounds are used widely in many industrial applications, including:
- pigments for textile dyes, paints, inks and plastics
- corrosion inhibitors
- wood preservatives
- metal finishing and chrome plating
- leather tanning.
How can hexavalent chromium affect my health?
It is unlikely that a person who is not involved in an industrial activity using hexavalent chromium compounds would be exposed to this form of chromium. However, if food or water was contaminated with hexavalent chromium then health effects may occur.
Workers who breathe in high concentrations of hexavalent chromium may experience health effects, such as:
- irritation to the lining of the nose
- nose ulcers
- runny nose
- breathing problems (wheeze, cough, shortness of breath).
Skin contact with some hexavalent chromium compounds may cause skin ulcers and allergic skin reactions.
If food or water is contaminated with high concentrations of hexavalent chromium irritation to the lining of the stomach and intestine, and damage to the male reproductive system may occur.
Hexavalent chromium compounds are classified as a known human carcinogen. It can cause lung cancer in workers exposed to high concentrations in the air. A higher risk of stomach tumours have been reported in studies where humans and animals have been exposed to high levels of hexavalent chromium in drinking water over a long time, however, the research is inconclusive.
How can I get exposed to chromium compounds?
Exposure to chromium may occur through inhalation (breathing it in), ingestion (eating or drinking it), and direct contact (getting it on your skin). The sources of exposure may include air, food, water, and contaminated soil and groundwater.
In food, chromium occurs in trivalent form (chromium III). It is extremely rare to find traces of hexavalent chromium in food.
Hexavalent chromium is present in tobacco smoke and smoking in enclosed spaces is the main source of exposure to airborne hexavalent chromium in the general population.
In some areas of South Australia, soil and/or groundwater (bore water) may be contaminated with chromium compounds due to past industrial activities.
Mains water is routinely tested and is safe.
How can I reduce exposure to chromium compounds?
SA Health advises that people using or intending to use groundwater (bore water) should have the water tested by an accredited laboratory to ensure that the water is suitable for its intended use. Contaminated groundwater should not be used for drinking, cooking, bathing, washing, and gardening.
Avoid smoking in enclosed spaces (for example, indoors or in cars) to limit exposure to hexavalent chromium present in cigarette smoke.
Trivalent chromium compounds may be marketed in dietary supplements as beneficial to health (for example in weight loss supplements). These claims are not supported by science. It is recommended to avoid excessive use of dietary supplements. For example, there is no scientific proof that “sugar balance” pills are effective, and their safety has been questioned by some.
You are encouraged to discuss any concerns with your regular GP. Your GP can contact Public Health Services for further advice on Chromium exposure.