Chromium 6  least of our worries

This story appeared in the Antelope Valley Press January 14, 2001

By BRENDA ZAHN
Valley Press Staff Writer

LANCASTER - Although it has topped the news in California in recent months, chromium 6 isn't the only chemical that concerns scientists as they evaluate what's safe for public consumption in the drinking water.

Scientists have their eye on several contaminants that can be found floating in the country's water supply in varying degrees. Arsenic, for one, has caused quite a stir.

The Environmental Protection Agency recently concluded that its longtime arsenic standard of 50 parts per billion is far too high, and that in fact the standard should be lowered to something closer to 5 ppb.

"(The public) should worry about arsenic, and virtually everything else they should not," said Bruce Macler, a drinking water toxicologist with the U.S. EPA. "Arsenic is out of line in terms of public health risk at its current level of 50.

"This is human health data on arsenic. We know it causes cancer in humans," Macler said.

Here's what an arsenic standard of 5 ppb means to the public, according to the EPA's proposal for reducing the standard to that level: If a person drank 5 ppb of arsenic over a lifetime, his or her risk of getting bladder cancer would be 1 in 10,000.

Want to know more? The following is a small sampling of the more than 80 other contaminants that the public needs to be aware of:

Perchlorate - There is no federal or state standard for perchlorate, a drug used to treat thyroid problems. Some worry that small traces of perchlorate in the drinking water could affect people's thyroids.

Loma Linda University Medical Center recently began testing perchlorate's effects on 100 human volunteers in an extremely rare case of human testing.

"It's clearly not enough of a toxin to say this is an acute health hazard that has to be dealt with immediately," Macler said about the drug.

The state of California has set an "action level" of 18 ppb, but that's more of a suggestion and is not enforceable under law.

Radon - There are no federal or state standards for radon, which is a naturally occurring radioactive material.

The EPA has proposed two separate radon standards - 4,000 picoCuries per liter for states with multimedia mitigation programs to clean radon from the air, and 300 picoCuries per liter for states without such programs.

Methyl tertiary butyl ether (MTBE) - This oxygenate was added to gasoline but is being phased out in California by 2003 because of public health concerns. It has been identified as an animal carcinogen.

There is no federal standard for MTBE. The EPA may, however, issue a secondary standard that deals with taste. California has a standard of 13 ppb and a secondary standard of 5 ppb.

"It's a suggestion," Macler said about the secondary standard. "We have it for a few contaminants where the taste threshold is much lower than where it will cause harm."

Macler said MTBE isn't a health risk at the levels at which it has been found. Others disagree, including Gov. Gray Davis, who ordered the state phase-out.

Nitrates - These are regulated at the federal and state levels, mostly because they're known to cause a rare disease called methemoglobinemia.

Macler described the disease as being similar to the effects of cyanide poisoning. It's so rare that the United States gets about one case every three or four years, he said.

The federal nitrate standard is 10 milligrams per liter (measuring just the nitrogen component of nitrate). The state standard is 45 milligrams per liter (measuring both the nitrogen and oxygen components of nitrate).

Trihalomethanes - This is a class of chemicals that includes chloroform (trichloromethane), the animal carcinogen bromodichloromethane, dibromochloromethane and bromoform, also an animal carcinogen.

The federal drinking water standard for all trihalomethanes combined is 100 micrograms per liter. The state standard is the same.

Williams said these chemicals can cause miscarriages and birth defects.

Haloacetic acids - This category consists of five haloacetic acids. The federal standard is 60 micrograms per liter, but they only have good toxicological information for one of the five acids. The state is in the process of adopting standards.

Williams said that haloacetic acids cause miscarriages and birth defects.

And there are many more water contaminants that make chromium 6's recent fame a little puzzling to those in the know.

The chemical became a topic of discussion partly thanks to the Julia Roberts movie "Erin Brockovich." The film chronicled the story of how residents of the San Bernardino County town of Hinkley won a $333 million settlement from Pacific Gas & Electric Co. because the company's underground tanks leaked chromium 6 into groundwater.

But if the public wants to worry about what's in its drinking water supply, there's plenty to keep them up at night, say officials.

"The amount of chromium 6 that's in the water, is that the thing that we need to be concerned about most?" asked Greg Dluzak of the Palmdale Water District. "Or do we need to be concerned about the arsenic that's in the water, or the MTBE, or all the other myriad of contaminants in the water?"