The chemical plume created by a spill in Charleston, West Virginia, is traveling down the Ohio River by Cincinnati today. The spill was discovered Friday; 7,500 gallons of a chemical used to clean coal called methylcyclohexane methanol—or MCHM—leaked into the Elk River, and contaminated the region’s drinking water for days.Now, communities along the Ohio River are dealing with the spill’s aftermath in different ways.The Cincinnati and Northern Kentucky water districts have elected to close water intakes until the chemical passes, just in case. But Louisville still plans to keep its intakes open. Spokeswoman Kelley Dearing-Smith said the water company believes the chemical will be so diluted by the time it gets here, it will be treated by the company’s riverbank filtration system and won’t pose any threat to human health.“This is not a health concern and we don’t believe customers are going to notice anything at all,” she said. “They certainly won’t notice any difference in the quality of their drinking water, and they shouldn’t notice any difference in the taste or odor of their drinking water.”That will probably be the case. But all of these water districts—in West Virginia, in Cincinnati, in Louisville—are basing their decisions on science which very may well be flawed: information from the Centers for Disease Control and Prevention.The CDC told communities that when levels of MCHM were below 1 part per million in drinking water (which means 1 milligram of MCHM in 1 liter of water), the water would be safe to use. The chemical will definitely be less than 1 ppm by the time the chemical plume reaches Louisville on Friday; thirty miles upstream of Cincinnati, it was detected at 14 parts per billion (ppb). By the time it reached Cincinnati, it had diluted to 5.4 ppb. It’ll be even more diluted by the time it gets here.But one of the problems with MCHM is that nobody knows very much about it, and that includes the CDC and others responsible for making sure the chemical doesn’t affect public health.Here's how a CDC official described the process of setting that 1 ppm standardto NPR's Elizabeth 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 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 . 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."Take a look at the Material Safety Data Sheet for MCHM, especially Section XI. There hasn’t been any testing to determine what long-term effects, if any, could result from MCHM exposure. That’s due to a major loophole in the country’s Toxic Substances Control Act (TSCA).MCHM has been used in this country for decades, and was grandfathered in when TSCA was passed in 1976. All those chemicals that fell under the same category were assumed to be safe—and the onus is on the Environmental Protection Agency to find evidence prove otherwise.Environmental groups have been pushing for reforms to TSCA for years. At the minimum, Kentucky Environmental Foundation director Elizabeth Crowe says there should be extensive information available about all of the chemicals used in the country.“Disclosure of the health and safety hazards associated with these chemicals, knowledge of how they can travel through the environment, knowledge of any safer alternatives, incentives for companies that actually will take the extra step and implement safer chemical alternatives,” she said. “These are the things communities definitely need and there’s no better reminder of the need for these kinds of reforms when a disaster like this happens.”And if there was an updated Material Safety Data Sheet for MCHM, regulators in West Virginia and Kentucky would have known immediately how serious the danger was to public health.
