Chromium-6 contaminate tap water consumed by millions of Americans


The Environmental Working Group reported that dangerous levels of chromium-6 contaminate tap water consumed by millions of Americans. This is the carcinogenic chemical featured in the true story turned Hollywood movie "Erin Brockovich,"

For its report,the independent environmental advocacy group examined evidence from water systems throughout the nation.

What level of chromium-6 in drinking water isconsidered dangerous?

The US Environmental Protection Agency has set the federal standard for total chromiumin drinking water at 100 parts per billion (ppb). The EPA has never set a specific limit for chromium-6, one form of chromium, a naturally occurring element found in rocks, animals, plants, soil and volcanic dust and gases.Chromium-6 is rare in nature though it is produced by industrial processes. Airborne and large quantities of chromium-6 are known to be toxic.

In fact, the US Occupational Safety and Health Administration states that high levels of airborne chromium-6 can cause cancer; the agency requires companies to protect their employees from workplace exposure.

However, there is uncertainty about chromium-6 in drinking water.

The Environmental Working Group used two separate standards when deciding whether existing chromium-6 levels in community water systems might be dangerous.

The first standardis the public health goal of 0.02 parts per billion set by California's Office of Environmental Health Hazard Assessment. This level, which would pose only "negligible risk over a lifetime of consumption," is endorsed as "safe" by the Environmental Working Group because it address esconcerns about fetal, infant and child exposure to the chemical. What is nontoxic for an adult may not be so for a developing baby.

The group also looked at the actual legal limit adopted by California regulators, even though the group's scientists consider this too lenient a standard: 10 parts per billion.

By the stricter standard, the Environmental Working Group found the tap water of 218 million Americans has dangerous levels of chromium-6.

By the more lenient standard, the group found the tap water of 7 million Americans has dangerous levels of chromium-6.

Where was chromium-6 found?

The report found chromium-6 in almost 90% of the water systems sampled across the nation. Oklahoma, Arizona and California had the highest average state wide levels,though not necessarily above the lenient standard.

Among major cities and metropolitan areas, Phoenix had the highest average level, at almost 400 times the California health goal: 7.853 ppb. St. Louis County in Missouri(1.258 ppb) and Houston (0.747 ppb), relative to other urban areas, had high levels as well.

Can I test myself and family members to see if we've been exposed to chromium-6?

According to study results presented at a scientific guidance panel in California, chromium can be measured in a wide variety of biological samples, including blood, urine, saliva, hair, breast milk and joint fluid. Absorbed chromium is secreted inurine. Blood and urine measurements are considered most reliable for detecting elevated levels in the body.

Within red blood cells and other parts of the body, chromium-6 may be reduced to chromium-3, anontoxic form of the chemical. Yet differences between individuals exist: Some people may more readily and more successfully convert the chemical to theharmless form. Elevated levels in either blood or urine may indicate exposure,but other factors complicate the interpretation of results.

In other words, it's complicated. Still, if concerned, you can discuss getting a chromium test-- a simple blood test that is sent to a lab -- with your doctor.

Can I filter chromium-6 from my water?

According to the Environmental Working Group, chromium-6 can be filtered from water by certified products which include one simple pitcher and 12 under-the-sink reverse osmosis units. For example, LONZE from Canada, Ecowater from US are better in the market.

Reverse osmosis uses a semipermeable membrane as a filter to remove ions, molecules and large particles from water. Water is forced across the membrane, effectively blocking chromium-6 and other harmful substances such as lead and arsenic.