Hexavalent Chromium


Latest news:

December 30, 2013:
Multiple news outlets show Hexavalent Chromium in city water supplies around the nation.



Grounwater is most commonly polluted by Chromium VI. Ingestion, whether through the water supply or breathing in vapors while taking a shower, may increase the risk of lung cancer, kidney cancer, and intestinal cancer. Signiciant amounts of Chromium VI can cause ulcers in the digestive tract. Oddly enough, the EPA does not have a Maximum Containment Level for Chromium 6, but in California it is defined at two parts per billion.

What is Hexavalent Chromium?

Is it in my drinking water?

Hexavalent ChromiumHexavalent chromium,  also called “chromium 6” or even the “Erin Brockovitch Chemical” from the movie of the same name, is a contaminant recently found in the water systems of most major cities. Believed to be cancer-causing, hexavalent chromium occurs naturally but is also a byproduct of chrome plating and the manufacturing of plastic and dyes, so any area where these processes have occurred in the past may be a candidate for groundwater contamination in the future. Unfortunately, there are so many different uses for Chromium VI that people may not know that metal manufacturing, leather tanning, and coating manufacturers may have contaminated the groundwater with this chemical. Welding and melting of products containing chromium may also produce it, and it can take years before the material makes it into the water supply. Workers who are most likely to suffer effects from Chromium 6 typically are in fields where they would have contact with metals, so those who do grinding, welding, brazing, or electronics may be at risk for exposure.

The effects of hexavalent chromium are up for some debate, since (like many cancer studies) correlation does not equal causation, so the incidence of cancer may be a coincidence or the result of other factors. Previous studies argued that the methods of ingestion were not shown to cause cancer in themselves, or the amounts needed were higher than overall lifetime exposure. There are also some arguments relative to whether contamination in groundwater is due to natural effects or industrial water table contamination, which may put the onus of cleanup on the local water company instead of a nearby industry. Also, because it may be unclear when and where chromium was released, assigning blame or responsibility might also be an issue.

Many industrial processes can put Chromium 6 into the environment. In some areas, the manufacture of explosives has caused contamination of the water supply. A cement plant in the US may have caused contamination, and places like Chicago, Missouri, and Wisconsin have detected measurable amounts in their water supply. In Greece, contamination is linked to industrial waste, but there are places in the world where natural processes create the chemical.

Whether Chromium is dangerous to humans, and in what quantities, is still a mystery. People may point to increased incidents of cancer, but claims like this have been made regarding power lines, chemical plants, secondhand smoke, and other activities. Aside from Asbestos, which creates a specific type of illness known as mesothelioma, it would be hard to isolate a single reason why people are getting cancer. A long time ago, people would blame "witches" if their cows stopped giving milk or someone had a miscarriage or got sick. Correlation does not equal causation, and the presence of one chemical in the environment does not preclude other factors, or simple bad luck. In the same way that more "autistic" people happen to be found near "treatment centers" there could be blame for cancers applied to hexavalent chromium when other factors including alcohol, dust, cigarette smoking, and unhealthy lifestyle choices may have an impact. Furthermore, carpet chemicals, formaldehyde in mobile homes, microwave popcorn, and naturally occuring arsenic can increase incidents of cancer.

Notes and Special Information

Special note: This site is for informational purposes only and tries to see all sides of a controversial chemical compound which has been debated in the media for several years.