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7:53 pm
Mon January 13, 2014

The Big Impact Of A Little-Known Chemical In W.Va. Spill

Originally published on Tue January 14, 2014 9:06 am

The chemical that was found last week to be contaminating the drinking water of hundreds of thousands of West Virginians is used to clean coal. But very little is known about how toxic it is to people or to the environment when it spills.

The chemical is called 4-methyl-cyclohexane-methanol, or MCHM. If you've never heard of it, you're in good company. Most chemists and toxicologists hadn't either — nor had the water company, nor emergency responders in West Virginia who had to deal with thousands of gallons of it spilling from a tank into the Elk River, just a mile and a half upstream from the intake for the region's drinking-water plant.

State officials say they looked to the Centers for Disease Control and Prevention to give them advice about when they could tell people the water was safe to drink again.

"There are unknowns," acknowledges Karen Bowling, West Virginia's secretary of health and human resources. "So we have to rely on what's already known about [it] and what's [been] tested about this particular chemical."

At the time of the accident, the CDC didn't have a standard for how much of this chemical in water is safe to drink.

So the agency had to come up with one.

The agency relied on the little research that had been done on the chemical — an animal study that established the lethal dose for rats.

"And from that you would decrease the proposed level down further and further, taking into account all the uncertainties," says Vikas Kapil, chief medical officer at the CDC's National Center for Environmental Health.

For instance, the CDC built a safety factor into the limits it set because health officials were uncertain whether people are more sensitive than rats to the chemical. And they added an additional margin of safety to account for certain populations — such as infants and the elderly — that might be especially vulnerable.

Kapil acknowledges that there was very little information to go on. Still, he says, drinking water that meets the CDC guideline of one part per million is "generally not likely to be associated with any adverse health effects."

West Virginia officials say they also turned to safety information companies, which are required to provide information on the chemicals they possess. But that so-called material safety data sheet included very little data in this case.

"The entries were largely 'data not available' for this particular compound," says Sharon Meyer, a toxicologist from the University of Louisiana, Monroe.

Meyer looked at the one published study she could find on the chemical and analyzed 4-methyl-cyclohexane-methanol's chemical structure. She says she saw nothing obvious that should present a concern to people who drank the water.

"I really think they were not exposed to extreme levels that would cause serious problems. But I don't have the data to definitively say this," Meyer says.

Experts weren't surprised that the scientific literature had so little information about MCHM, because there is very little toxicological research about many chemicals. Priority for testing is given to chemicals used by consumers or in food preparation.

"There are 85,000 chemicals in commerce right now in the United States, and we cannot possibly test all the chemicals for all their different properties," says Rolf Halden, an engineering professor at Arizona State University who researches how chemicals move through the environment and people.

Halden used a computer model from the Environmental Protection Agency to calculate how this chemical would behave in the environment.

He says it likely would not persist for long; half of it would be gone from water within two weeks, and half of it from soil within a month. That's because microbes in the soil will likely break it down.

"I would not be terribly concerned about long-term contamination of the environment with this chemical," Halden says.

Still, the spill shed light on how little is known about many chemicals. Members of Congress have been debating for years whether to update the 1976 law that governs these chemicals, the Toxic Substances Control Act.

Lynn Bergeson, a lawyer who specializes in the regulation of toxic chemicals, says she hopes the West Virginia accident will convince lawmakers that it is urgent for them to act.

"These incidents are very painful for the local residents there in West Virginia," Bergeson says, and "are embarrassing to federal and state governments" that don't have the information residents want.

Copyright 2014 NPR. To see more, visit http://www.npr.org/.

Transcript

AUDIE CORNISH, HOST:

We're going to focus on the chemical that's caused all this trouble in West Virginia. It's commonly used to clean coal. But as NPR's Elizabeth Shogren reports, it's also something of a mystery.

ELIZABETH SHOGREN, BYLINE: The chemical is called 4-methylcyclohexane methanol, or MCHM. If you've never heard of it, you're in good company. Most chemists and toxicologists haven't either, nor had the water company or emergency responders in West Virginia who had to deal with thousands of gallons of the stuff spilling from a tank and contaminating drinking water.

West Virginia's Secretary of Health and Human Resources, Karen Bowling, says the state relied on advice from the Centers for Disease Control and Prevention.

KAREN BOWLING: There are unknowns, so we have to rely on what is already known about and what's been tested about this particular chemical.

SHOGREN: At the time of the accident, the CDC didn't have a standard for how much of this chemical in water is safe to drink, so they had to come up with one. The agency relied on an animal study that established what was lethal for rats. Vik Kapil is the chief medical officer at the CDC's National Center for Environmental Health.

VIKAS KAPIL: And from that, you would decrease the proposed levels down further and further, taking into account all the uncertainties.

SHOGREN: Kapil acknowledged that there was very little data to go on. West Virginia officials say they also turned to safety information companies must provide on chemicals they possess. Toxicologist Sharon Meyer says it didn't say much.

SHARON MEYER: And the entries were largely data not available, data not available for this particular compound.

SHOGREN: Meyer is an associate professor at University of Louisiana at Monroe. She says she analyzed the compound's structure and saw nothing obvious that should present a concern to people who drank it.

MEYER: I really think that they were not exposed to extreme levels that would cause serious problems. But I don't have the data to definitively say this.

SHOGREN: Arizona State University professor Rolf Halden wasn't surprised that the scientific literature had so little information about MCHM.

ROLF HALDEN: There's 85,000 chemicals in commerce right now in the United States, and we cannot possibly test all the chemicals for all the different properties.

SHOGREN: Halden researches how chemicals move through the environment and people. He used a computer model from the Environmental Protection Agency to calculate how this chemical would behave in the environment. He says it likely would not persist. Half of it would be gone from the water in two weeks and half from the soil in a month. That's because microbes in the soil will likely eat it.

HALDEN: I would not be terribly concerned about long-term contamination of the environment with this chemical.

SHOGREN: Still, the accident shed a light on how little is known about many chemicals. Lawyer Lynn Bergeson specializes in the regulation of toxic chemicals.

LYNN BERGESON: These incidents are very painful for the local residents there in West Virginia. They are embarrassing to federal and state governments that would appear to not have as much information as they would like to be able to report to local residents.

SHOGREN: Bergeson hopes this accident will spark new interest in updating the 40-year old law that governs toxic chemicals. Elizabeth Shogren, NPR News, Washington. Transcript provided by NPR, Copyright NPR.

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