What is chromium?
Chromium is a naturally occurring element found in rocks, soil, plants, animals, and in volcanic dust and gases. Chromium has three main forms chromium(0), chromium(III), and chromium(VI). Chromium(III) compounds are stable and occur naturally, in the environment. Chromium(0) does not occur naturally and chromium (VI) occurs only rarely. Chromium compounds have no taste or odor. Chromium(III) is an essential nutrient in our diet, but we need only a very small amount. Other forms of chromium are not needed by our bodies.
Chromium is used for making steel and other alloys, bricks in furnaces, and dyes and pigments, and for chrome plating, leather tanning, and wood preserving. Manufacturing, disposal of products or chemicals containing chromium, or burning of fossil fuels release chromium to the air, soil, and water.
What happens to chromium when it enters the environment?
- Chromium particles settle from air in less than 10 days.
- Chromium sticks strongly to soil particles.
- Most chromium in water sticks to dirt particles that fall to the bottom; only a small amount dissolves.
- Small amounts move from soil to groundwater.
- Fish don't take up or store chromium in their bodies.
How might I be exposed to chromium?
- Breathing contaminated workplace air (stainless steel welding, chromate or chrome pigment production, chrome plating, leather tanning.)
- Handling or breathing sawdust from chromium treated wood.
- Breathing contaminated air, or ingesting water, or food from soil near waste sites or industries that use chromium. Very small amounts of chromium(III) are in everyday foods.
How can chromium affect my health?
All forms of chromium can be toxic at high levels, but chromium(VI) is more toxic than chromium(III).
- Breathing very high levels of chromium(VI) in air can damage and irritate your nose, lungs, stomach, and intestines.
- People who are allergic to chromium may also have asthma attacks after breathing high levels of either chromium(VI) or (III).
- Long term exposures to high or moderate levels of chromium(VI) cause damage to the nose (bleeding, itching, sores) and lungs, and can increase your risk of non-cancer lung diseases.
- Ingesting very large amounts of chromium can cause stomach upsets and ulcers, convulsions, kidney and liver damage, and even death.
- Skin contact with liquids or solids containing chromium(VI) may lead to skin ulcers. Some people have allergic reactions including severe redness and swelling.
We don't know if chromium harms the fetus or our ability to reproduce. Mice that ingested large amounts of chromium had reproductive problems and offspring with birth defects.
How likely is chromium to cause cancer?
The Department of Health and Human Services has determined that certain chromium(VI) compounds are known carcinogens. This is based on increased lung cancer in some workers who were exposed to chromium. Animal studies also indicate chromium(VI) is a carcinogen. We do not have enough data to determine if chromium(0) or chromium(III) are carcinogens.
Is there a medical test to show whether I've been exposed to chromium?
Chromium can be measured in the hair, urine, serum, red blood cells, and whole blood. Tests for chromium exposure are most useful for people exposed to high levels. These tests cannot determine the exact levels of chromium you were exposed to or predict how the levels in your tissues will affect your health. Skin patch tests may indicate if you are allergic to chromium.