Earlier in January, West Virginia experienced a large chemical spill in its capital city, Charleston. A large supply tank holding nearly 10,000 gallons of a chemical called 4-methylcyclohexanemethanol (MCHM) leaked into the Elk River, forcing a state of emergency that prevented the use of water by a quarter of the entire state’s population. There has been a lot of controversy surrounding this spill, and a lot of people are disenfranchised, angry, and worried about the long-term consequences.
What are these chemicals that leaked into the Elk River? What were they for, and what were they doing in that spot?
The Chemistry of MCHM
The economy of West Virginia depends heavily on its rich coal deposits. Unfortunately, it is also one of the dirtiest means of generating electricity, important though it may be. The burning of coal releases pollutants into the air that result in contaminated water and acid rain in nearby areas. The advent of clean coal technology has provided industry a way to reduce the amount of harmful pollutants that leave coal firing electric plants. An important technique for cleaning coal is the use of frothing agents like MCHM.
MCHM is a surfactant that helps to separate molecules with different polarities. In essence, it’s like soap, which has a polar head and a non-polar tail, allowing the molecules to align themselves to interface with dirt and grease and other compounds that do not mix with water. By surrounding these nonpolar molecules, the soap provides a sort of bridge that allows everything to be carried away by water. Coal itself has a number of these nonpolar contaminants that cannot be easily separated using water. Molecules like sulfides, carbonates, and oxides are often nonpolar like coal, so companies will use surfactants like MCHM to help separate them. The reason these compounds can be separated is because the extent to which they are hydrophobic is different. Therefore, using different strengths of surfactant, we can separate the coal from the dirtier residue present in the bulk material. This is important because the impurities that come out of the ground with the coal are the major causes of pollution.
Why Is It Dangerous?
When the chemical spilled into the Elk River, there was significant concern about the toxicity of MCHM. Very little work into the toxicity of this compound had been performed in humans. The only indication of how dangerous the substance might be came from a World Health Organization study that showed the class of compounds to which MCHM belongs (alicyclic carbohydrates) has a low acute toxicity. The oral dose needed to kill 50% of rats (median lethal dose, LD50) ranges was 825 mg/kg, making it less acutely toxic than aspirin or caffeine (LD50 of 200 and 192 mg/kg).
Still, consumption of the chemical can make you sick. Some residents who consumed tap water before the “do not drink” advisory took effect experienced nausea, diarrhea, and other gastrointestinal symptoms.
What Is Being Done About It?
The MCHM spill represents a pretty big challenge to the water system. No effective means of separating s soluble chemical like this from water exists. Remember, this is like a soap molecule, and it mixes completely with water itself. As such, the only thing that can be done is flushing the plumbing systems, similar to how you remove soap from the sink. After enough flushing, it is thought that the chemical will be diluted enough that it will no longer be a problem.
Being from and living in West Virginia (Morgantown, to be exact), this event does hit close to home. In fact, this is mostly what you hear coming out of West Virginia: environmental disasters like coal mine explosions and chemical spills. My father works at a plant that works with silane compounds (materials based on silicon), and they deal with things like huge clouds of hydrochloric acid that waft over the roads. In another more recent incident, a chemical truck carrying sodium hydroxide wrecked and leaked the caustic chemical (http://news-register.net/page/content.detail/id/594946/W-Va–2-Reopens-Following-Lye-Spill.html?nav=515). That one happened about two miles from my old house in Sistersville.
To date, industry and the people of West Virginia have had a pretty shaky relationship. On the one hand, these companies bring excellent job opportunities that offer high pay, so there is resistance to enact more safeguards as they may drive businesses out of the area hurting the economy. At the same time, many average West Virginians feel exploited and endangered by this progress. Overall, it’s a complicated situation, but these types of incidents will likely lead to legislative action by the state government to help protect citizens and workers.
Written by Zach Hartman
Zach Hartman is a freelance medical writer specializing in educational writing. He received his PhD in biochemistry and molecular biology from West Virginia University in 2013, where he worked with the signaling protein SHP2 and its role in breast cancer. Now he covers a broad spectrum of topics.