CDC Rationale for West Virginia Tainted Water Explained

After a chemical spilled into the Elk River and tainted the water supply of 300,000 West Virginians, health officials’ biggest concern was determining at what levels the water would again be safe to drink.

If it was safe to drink, they believed, it would be safe to use for such things as showering and washing hands, according to a letter the director of the Centers for Disease Control and Prevention sent to U.S. Rep. Shelley Moore Capito.

Patients visiting the emergency room told a different story.

For two weeks after the Jan. 9 spill, residents showed up in the emergency room complaining of issues related to breathing and coming into contact with the water, according to ER reports analyzed by health officials and released publicly last month.

ER visits spiked on Jan. 15, two days after state and water company officials cleared some people to start flushing out their home systems. Symptoms ranged from rashes to vomiting – even though chemical levels were 250 times lower than what CDC called safe for drinking.
Capito asked the CDC about the risks of breathing chemical vapors and skin contact last month. Her office provided the agency’s response letter to The Associated Press.

“Since ingestion was considered the greatest risk, we believed it would also be protective for other routes of exposure,” CDC Director Thomas Frieden explained in the letter dated May 20.

Armed with little toxicological information on the coal-cleaning chemical crude MCHM, Frieden said the agency believed the chemical would not cause problems related to inhalation or skin contact in the long term.

That is despite the agency’s safety mark only focusing on the short term. CDC assumed people were going to be exposed to the chemical for two weeks.

The chemical’s material safety data sheet says at elevated temperatures, its vapors can cause eye and respiratory tract irritation. But CDC’s letter says there was a “data gap” about how the chemical behaves once diluted in heated water, such as in showers. Ongoing studies at Virginia Tech are looking into the showering question, the CDC said.

Federal officials still are trying to figure out how safely people can breathe in the chemical. Over the next few months, the Environmental Protection Agency will work on detecting the spilled chemical in air and creating a corresponding safety standard.

People across nine counties were banned from using their water for anything but fighting fires and flushing toilets for four to 10 days after the January spill.

Until the regional water company changes all its filters by mid-June, researchers say chemical traces will likely keep finding their way into the water distribution systems, albeit at levels thousands of times weaker than what CDC deems safe.

The CDC letter also estimates people were exposed to tainted water for several hours, or even a day or two, before they stopped using the water in January.