Environmental Health

Hexavalent Chromium in Drinking Water? APHL Responds

By Jennifer Pierson, MPH, Senior Specialist, Environmental Health, APHL

APHL member laboratories work to protect the public’s health every day. Part of this work includes ensuring the nation’s drinking water is safe for consumption by conducting tests in accordance with the Environmental Protection Agency’s (EPA) standards and that are in compliance with the Safe Drinking Water Act (SDWA.)

On Monday, the Environmental Working Group (EWG) released a new report stating they found Chromium-6 (hexavalent Chromium) in the drinking water of 35 cities across the country. In 2000, the movie Erin Brockovich made hexavalent Chromium a familiar carcinogen. Currently the EPA does not have a maximum containment level for Chromium-6 in drinking water but they do have a maximum of 100 ppb for total Chromium in drinking water, which includes several Chromium compounds as well as Chromium-6. APHL member laboratories test drinking water for total Chromium per EPA and SDWA standards and no cities are above EPA’s limit of 100 ppb. Some of these laboratories even go above and beyond to test for emerging contaminants and other pollutants to ensure the drinking water is safe.

The EWG report made a splash in the media on Monday because of the fear of hexavalent Chromium. However, the findings indicated most cities only have about 0.18 ppb or less, a fraction of the 580 ppb found during Brockovich’s investigation and a fraction of the EPA’s limit for all Chromium compounds. Many public health departments and drinking water programs responded to the findings and restored calm to rising public’s fears.

It is our scientific understanding that some of the quality controls and analytical procedures used to test for Chromium-6 by EWG’s contracted commercial laboratory may be questionable. Scientists are also concerned that the method interferences and sensitivities may produce false results. APHL member laboratories believe alternative methods using ICP-MS instrumentation are far more sensitive and may be the better method to detect Chromium-6 in drinking water.

EPA is already reviewing the findings of the EWG report and has been working on this issue for months. This past September, EPA released a draft scientific review to assess Chromium-6 in drinking water. This draft if still out for comment and should be finalized some time in 2011. EPA will then consider the results and will determine if a new standard for Chromium-6 is necessary.


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