Caitlin McGlade

The Republic | azcentral.com

ASU researchers are helping to develop a product that aims to make it easier for you to reduce chromium-6 exposure at home

Carbon filters found in most common home filter devices won't touch chromium-6

Consumers looking to buy products to reduce home exposure should make sure their choice is certified by the National Sanitation Foundation

Chromium-6 taints drinking water all over the United States and comes from natural and industrial sources. Ridding it from the national scene would be costly. Even reducing your exposure at home is difficult.

But as the U.S. Environmental Protection Agency decides whether to require tighter limits on the cancer-causing agent, researchers at Arizona State University are helping to develop a technology that aims to protect consumers.

ASU, Yale University, University of Texas at El Paso and Rice University have teamed with private industry to create a water filter that should be easier to use and less expensive than reverse osmosis, an ASU scientists says.

Reverse osmosis is the method often recommended to reduce exposure to chromium-6 at home, but these systems can cost hundreds of dollars and require vigilance to keep them well maintained.

And that method is at odds with region-wide efforts to conserve water amid potential shortages, wasting up to 70 percent of the water it processes.

Carbon filters found in most common home filter devices won't touch chromium-6. But the research group plans to release a revamped carbon block filter that tackles the contaminant.

The product should hit the market within about 12 to 18 months, said Paul Westerhoff, senior sustainability scientist of Arizona State University's Julie Ann Wrigley Global Institute of Sustainability. He's one of the scientists on the team.

The project is funded by a $3.5 million annual grant from the National Science Foundation and membership fees payed by industrial partners.

Report: More than 200 million Americans exposed to the carcinogen

The Environmental Working Group, an environmental health advocacy non-profit, reported this week that more than 200 million Americans drink water that contains more chromium-6 than California scientists recommend.

The authors of the report calculated that about 12,000 people are at risk of getting cancer from ingesting the pollutant.

Consumers looking to buy products to reduce home exposure should make sure their choice is certified by the National Sanitation Foundation. Westerhoff said consumers need to look for the blue "NSF" label to that the product's claim has been validated.

Environmental Working Group recommends reverse osmosis and one pour-through filter to reduce home exposure. It is unclear, however, whether the product by Zero Technologies filters chromium-6 down to the California standard — the nation's most stringent.

The company certifies the product to reduce chromium-6 levels to less than 50 parts per billion.

Consumers should also know that home test kits for chromium-6 won't tell you if you're within California limits. Such testing products tend to detect chromium-6 in parts per million. If you're worried about chromium in your well, you'll likely have to submit samples to a laboratory to find out if you're close to California's health goal, Westerhoff said.

Chromium-6 gained national attention in the 1990s when then-legal clerk Erin Brockovich helped residents in Hinkley, Calif., settle a massive case against Pacific Gas and Electric Co. The electric utility had polluted the groundwater with cancer-causing chemicals, which Brockovich linked to illnesses in the town.

The stuff is pervasive. It leaches into water either naturally or from runoff from industries such as electroplating, leather tanning and textile. Chromium is an abundant element in Earth's crust, found in rocks, plants, soil, volcanic dust, humans and animals. Chromium-6 is created when chromium oxidizes. The contaminant occurs naturally in metro Phoenix.

The EPA established the current legal limits on chromium in 2001 based on preventing skin reactions, but five years ago reported that chromium-6 is likely to be carcinogenic to humans. The agency is considering lowering the limit, which is 5,000 times the amount recommended by California scientists, but will not release a draft assessment until next year.

Other groups also calling for higher standards

The California scientists are not alone with their call to reduce the contaminant's concentration to levels below 1 part per billion. New Jersey's Drinking Water Quality Institute and North Carolina's Department of Environmental Quality determined a health-based limit just slightly higher than California's scientists had.

The California Office on Health Hazard Assessment's public health goal is .02 parts per billion. ​That means if you drink water containing that amount of chromium-6 over 70 years, you have no more than a one-in-a-million chance of getting cancer.

The office determines such goals on health alone — economic or technical feasibility not included. The state set its legal limit to 10 parts per billion, based on health, economic and technically feasibility.

Consuming chromium-6 at that rate over 70 years gives you a 500-in-a-million chance of getting cancer from it.

The Environmental Working Group singled out drinking water in Arizona as having some of the highest amounts of chromium-6. Keep in mind, though, that most utilities that tested for it in the state reported average levels of the contaminant below California's legal limit. But that limit is 500 times the health goal.

This week's report follows one released in 2010 by the same group, which found that 31 of 35 cities the authors sampled contained the compound Brockovich had made famous. The EPA responded by requiring utilities serving at least 10,000 customers to test for the compound, along with a fraction of smaller water providers.

Even still, demand for products that reduce chromium-6 exposure has been lukewarm, especially compared to the rush of demand for lead-removing products, said Doug Kellam, CEO of ZeroTechnologies.

"I don't think that people are as aware of chromium-6 as they should be," Kellam said. "It's more nebulous as to how it gets In your water (than lead) and there's also some huge disagreements on the standards."

While the U.S. EPA deciphers how to regulate chromium-6, utilities wait for guidance and brace for costs. But you don't need to panic.

Health recommendations are based on decades of exposure.

Drinking water exceeding those goals for one day or even for the next five years statistically doesn't change your cancer risk that much, ASU's Westerhoff said.