Dave Mistich Published

Panel Deems CDC Screening Level for MCHM 'Safe', Establishes Own 8 Times As Strict


Independent researchers working together on the taxpayer-funded WV TAP project have already released an expert odor analysis for Crude MCHM, and have delivered the findings of their 10 home testing pilot project. However, the public has repeatedly called for an understanding of potential health effects from the January spill of Crude MCHM by Freedom Industries.

On Thursday, an expert panel reviewed available health effects data on the chemicals involved in the spill, evaluated the Centers for Disease Control and Prevention’s short term drinking water screening level and also offered their own.

WV TAP’s health effects panel was chaired by Dr. Michael Dourson of Cincinnati-based nonprofit consulting firm Toxicology Excellence for Risk Assessment, or TERA. Experts reviewed the CDC’s short term drinking water screening level and also established their own for the chemicals in question. All this while not just considering those who ingested the contaminated water, but also those whose skin may have been exposed or inhaled the chemical.

The panel also expanded upon the CDC’s safety factor of exposure on a one-year old child and extended it to what they deem the most highly exposed population: a formula-fed infant.

“So, we have safe levels of exposure that are protective of all populations and these are average levels for up to 28 days because that’s the length of the study,” said Dourson referring to prior research on MCHM conducted on rats.

“Now, some people would argue that, you know, a rat 28 days is not a human 28 days.  And that’s correct. That’s probably a little bit more in humans.”

Dourson said the CDC used “traditional methods” in determining their 1 part per million short term drinking water screening level. He said the federal agency’s number is “reasonable” and should be considered “safe.”

Still yet, Dourson and WV TAP determined their own screening levels for the chemicals involved in the Freedom Industries spill. WV TAP’s review of available data on crude MCHM yielded their own screening level eight times as stringent as the CDC’s.  

“For 28 days and the average level [of daily exposure], these levels are 120 parts per billion for MCHM, which is different than the CDC number. 250 parts per billion for DiPPH, which the CDC did not give a number. We were able to see the data and feel comfortable enough to do this,” Dourson explained.

“And then 850 parts per billion for PPH. The CDC gave a number of 1,200, I believe.”

The WV TAP panel made use of a literature review compiled by Dr. Craig Adams of Utah State University, email correspondence with the CDC, as well as syndromic surveillance data provided by Dr. Rahul Gupta of the Kanawha Charleston Health Department.

Health data compiled by the Bureau for Public Health from doctors practicing in the Kanawha Valley in the wake of the spill, which is currently being reviewed by the CDC, was not available to panel.

Dourson said WV TAP researchers would like to see additional studies on MCHM and skin irritation, the effect of the chemical on pregnant animals, as well as proper organization of all available data on exposures and health effects from immediately following the spill.

“Again, I wanted to emphasize these are preliminary findings. The levels that were coming up were safe,” said Dourson. “The chemicals themselves—you know, from a look at all of the toxicity—they’re not very toxic. But, there still is a concern.”

WV TAP project manager Jeff Rosen contextualized the panel’s findings by referring to a recent expert odor analysis study by Dr. Michael McGuire, as well as the 10 home testing project overseen by Dr. Andrew Whelton.

The highest levels of MCHM from home testing came in at 6.1 parts per billion, although expert odor analysis indicated Crude MCHM can be detected as low as 0.15 parts per billion.

“Those levels that can be smelled are way below the level that Dr. Dourson just reported to you that are safe. Way below,” said Rosen.

“So, you can smell the Crude MCHM at levels that are dramatically, at least two orders of magnitude—two, maybe three, orders of magnitude—lower than the levels that are safe for your consumption, he added.”

Yet, despite WV TAP’s evaluation thus far, members of the public remain suspicious. Maya Nye of People Concerned About Chemical Safety, pressed for answers.

“I read in some of the reports that PPH was noted as being harmful to aquatic life, slightly toxic. Focal necrosis was something that was listed as a potential health risk,” Nye began in asking a question about a recent report from the Wall Street Journal, which cited a 1998 Material Safety Data Sheet on MCHM.

The document indicated potential blood disorders as a result of exposure to the chemical.

“In the 28 day study, one of the effects—that was this idea of first adverse effect, critical—was anemia and one of them was damage to the kidney,” explained Dourson in response to Nye’s question.

He said the WV TAP panel took this into consideration, as did the CDC.

WV TAP’s $760,000-plus contract ends May 15, at which time the group plans to submit a proposal for an expanded home testing program currently being designed by Rosen. No funding has yet been approved by Governor Tomblin to continue the research.

Tomblin said during a Tuesday press conference that , in order to continue the project or provide any more funding to WV TAP, the state would have to write a new contract and put it out for bidding. The process would work the same as any other contract would be required under state purchasing procedures.

The team’s initial funding was granted under executive powers that allow the governor to approve funding during a state of emergency, but that state of emergency is no longer in place.