Water Filter to Remove Hexavalent Chromium-6
water filter to remove chromium-6, a suspected human carcinogen, that has been detected in 31 of 35 major U.S. cities tested
The results of laboratory tests commissioned by Environmental Working Group (EWG) were released in December 2010, indicating that chromium-6 (hexavalent chromium) has been detected in the drinking water in 31 major U.S. cities - a staggering 89% of the cities tested. While chromium-6 detection was anticipated in several of the cities, the results were far more widespread than ever imagined. It is estimated by the EWG that at least 74 million Americans in 42 states drink chromium polluted water, much of it in its suspected carcinogenic hexavalent form.
While relatively unknown to most Americans, hexavalent chromium first attracted national attention when it was detected in the water supply of Hinkley, California. A popular movie starring Julia Roberts (2000) was based on the story of Erin Brockovich and her efforts to hold the utility company, Pacific Gas & Electric, responsible for the contamination and illnesses that were believed to have resulted. The case ended with PG&E paying more than $330 million in damages.
A draft toxicological review by the U.S. Environmental Protection Agency (EPA) released in September 2010 concluded that chromium-6 in drinking water is "likely to be carcinogenic to humans". Additional studies have similarly concluded that chromium-6 increases the risk of various stomach and other gastrointestinal tumors in animals and likely humans. At present, the EPA does not have a legal maximum level of chromium-6 that can be in municipal drinking water, nor does it require utilities to test for it separate from other forms of chromium. However, the State of California has proposed a public health goal of 0.06 parts per billion, a level that it feels would substantially reduce cancer risk. The EWG testing revealed that in the 31 cities where detectible levels of chromium-6 were detected, 25 had levels higher than this proposed goal level, and in one case, the results exceeded this level by more than 200 times. The average level detected in all 35 cities tested exceeded the proposed public health goal level by a factor of 3.
Chromium is found in water supplies in several forms. Most water utilities are only required to test for "total chromium", which includes the non-toxic essential mineral trivalent chromium, and, of course, the hexavalent form. The concern arises from the fact that utilities are not testing specifically for the potentially dangerous hexavalent form, and the allowable level of "total chromium" is 1,700 times higher than the level proposed as a health goal by the State of California for the hexavalent form. The EWG confirms that this concern is well founded.
What can consumers do to ensure their water is free of chromium?
Rebecca Sutton, a senior scientist with the Environmental Working Group and the lead author of the study, concluded, "Getting a water filter is a great way to protect yourself and your family. It's a step you can take yourself; you don't have to wait for government action." The infrastructure required to treat chromium-6 on a municipal level takes, in many cases, years to implement, whereas homeowners can acquire relatively inexpensive but very effective treatment systems for their own home and have them installed in a matter a days. At the same time, the same home water filtration equipment will provide protection against other common water contaminants, including pharmaceuticals, which have also raised considerable concerns over the past year after being detected on a widespread basis in the U.S. municipal water supply.
Traditional activated carbon filters cannot remove chromium. We strongly recommend the use of an under sink reverse osmosis (RO) system for chromium reduction. Reverse osmosis offers the highest contaminant reduction rates for chromium of any current residential water treatment technology. Moreover, it also offers excellent protection against other potential contaminants, is relatively easy to install, and is inexpensive.
To ensure that you are getting the protection you are expecting, we recommend that homeowners select an RO system with NSF/ANSI Standard 58 validation for chromium-6 (hexavalent chromium). We recommend the following unit (click on the picture for more details):