EPA air ‘screening level’ iffy for W.Va. MCHM cleanup
Nearly four months after the Elk River leak from Freedom Industries, federal regulators are working on an air-quality screening level for the toxic chemical MCHM. It’s not clear, though, that the standard and a new MCHM air sampling method will be ready in time to monitor chemical levels during the cleanup of the Freedom site.
The U.S. Environmental Protection Agency is devising the “inhalation screening level” and a new sampling method, with both expected to be completed in the next few months, said EPA press secretary Liz Purchia.
State officials say the EPA is responding, at least in part, to a request West Virginia made for assistance in responding to the sorts of licorice-odor complaints that came in from local public schools in the weeks after the Jan. 9 leak of the coal-cleaning chemical Crude MCHM from the Freedom operation.
However, the EPA also is acting based on a previous West Virginia Department of Environmental Protection request that federal officials come up with a more comprehensive way of monitoring air quality for MCHM during the dismantling of Freedom’s chemical storage tanks, and the cleanup of the Elk River site where the leak occurred, state officials said.
Kelley Gillenwater, spokeswoman for the DEP, said that whatever the EPA comes up with might be something the DEP can use in the future.
“Depending on what their recommendations are, we could, potentially, use the standard and the monitoring methods during the spill site cleanup,” Gillenwater said Thursday.
DEP officials and investigators from the U.S. Chemical Safety Board have cautioned that the demolition of MCHM storage tanks at the Freedom site could prompt the release of more of the chemical into the air and bring back the licorice-like odors residents became familiar with after the leak.
Purchia said the EPA is developing “a health protective inhalation screening level” that may be used, along with information on monitored air concentrations of MCHM, during the site cleanup process “to advise the public when exposure to MCHM is not anticipated to be harmful.
“This shot-term inhalation screening level for MCHM is not a standard or a regulation,” Purchia said. “This level represents a concentration of MCHM in air where it is not anticipated that health effects would occur if someone were exposed to air concentrations below this level.”
Demolition of the tanks, though, is scheduled to start as early as May 12, and the EPA has said only that it would complete its screening level and sampling method in the “next few months.”
Gillenwater said it’s possible the EPA work won’t be completed in time for the DEP to use the screening level or the sampling method during the site cleanup, or at least during the dismantling of the tanks that contained MCHM. Also, Gillenwater said, the state needs to see what the EPA comes up with before deciding if the DEP will use it.
“We haven’t yet seen the MCHM screening level standards and methodology from the EPA and, therefore, can’t say with any certainty how we would use these standards,” Gillenwater said. “The screening and monitoring methods could, potentially, be used to monitor air during the spill site cleanup or in the future to respond to MCHM odor issues if our agency has the adequate training, equipment and any other resources that might be necessary.”
In the hours after the leak, the U.S. Centers for Disease Control and Prevention rushed to set a 1-part-per-million public health “screening level” for MCHM. However, agency officials considered only exposure through drinking contaminated water — not other exposure routes, such as inhalation or skin contact — and the CDC’s figure continues to be strongly criticized by outside public-health experts.
Gov. Earl Ray Tomblin and state public-health officials, along with West Virginia American Water, advised residents that they could resume using water that met the CDC’s drinking-water standard, despite increasing evidence after the leak of adverse reactions from skin contact or breathing MCHM fumes.
On its official chemical-safety data sheets, MCHM-maker Eastman Chemical warned that vapors from MCHM “may cause irritation of the eyes and respiratory tract” and that the chemical “causes skin and eye irritation.” While that information was available to the CDC and other public-health officials the day of the leak, the screening level used by government officials and the water company assumed that residents would be exposed only through drinking the water, not also through skin contact and inhalation of fumes.
Last month, the Tomblin administration’s independent West Virginia Testing Assessment Project said risks from inhalation and skin exposure should have been considered by the CDC. WVTAP tried to account for those risks and, in doing so, came up with a screening level of 120 parts per billion, about eight times more stringent than the CDC figure.
Also, while MCHM concentrations in residential tap water tested by WVTAP were far below that 120-parts-per-billion level, WVTAP leader Andrew Whelton has been careful to emphasize that no testing of home taps was done in the immediate aftermath of the leak. Without such data, Whelton said, no one knows for sure what levels of MCHM residents were exposed to both before and immediately after the water company issued a “do not use” order.
Richard Denison, a scientist with the Environmental Defense Fund, said it seems a little bit late for federal officials to be coming up with a screening level for MCHM inhalation.
“Ideally, you would have all of this in place before the problem,” Denison said. “It very much seems like the horse has left the barn.”
Denison said, if it’s done in time, the screening level could be helpful during the site cleanup, especially to monitor worker exposures, or perhaps could even be used to look back to estimate the risks of the exposures residents experienced during the leak.
“But it’s going to be highly speculative,” Denison said. “It sounds like it’s going to be of limited utility.”
Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.