Kanawha Valley residents likely breathed in levels of the chemical crude MCHM that exceeded a federal inhalation advisory level while they were "flushing" their home plumbing systems following the January 2014 spill that contaminated the region's drinking water supply, according to a little-noticed study made public earlier this year.
The study, co-authored by an engineer hired by the Tomblin administration to investigate the spill's effects, used computer modeling to estimate the potential concentrations of chemicals released into the air during the flushing process. The study emphasized that, because federal, state and local agencies coordinating the response to the spill did not take indoor air quality measurements, "the extent of this incident is still unknown."
In the study, modeling by researchers at Colorado State University and Purdue University found levels of MCHM in indoor air during the "flushing" advised by state officials and West Virginia American Water was greater than concentrations considered acceptable under a U.S. Environmental Protection Agency "screening level" that EPA developed months after the spill.
The modeling used the highest level of MCHM found in the region's drinking water distribution system and also lower MCHM concentrations from later tap water sampling that was done in later January 2014, after the "do not use" order was lifted.
In some instances, such as flushing of a kitchen sink, the modeling found that air concentrations of MCHM were only higher than the EPA inhalation guidance when those air concentrations were based on the highest levels of MCHM found in the region's water. In other instances, such as flushing of bathroom sinks and half-bathroom sinks, the MCHM levels in the air were modeled to have been greater than the EPA exposure guidance when the modeling used the lower levels of chemicals found in tap water weeks after the spill.
While far from definitive, the study at least seeks to address one of the key issues left unexamined in any meaningful way by federal government scientists when they earlier this month issued a final report asserting that the spilled chemicals were found to have no adverse health effects at the doses residents would have been exposed to by drinking contaminated water.
"I am not aware of any organization that conducted indoor air chemical monitoring during the spill and there is some uncertainty in modeling," said study co-author Andrew Whelton, a Purdue engineer whose previous work on the spill included an investigation for Gov. Earl Ray Tomblin. "As a result, we cannot be 100 percent certain what the exposures were, but modeling results indicate it is plausible residents were exposed to levels above EPA's inhalation screening level."
Whelton noted that other research has provided evidence of a connection between adverse health effects and inhalation exposures to MCHM.
One study found that half of the residents surveyed by the researchers involved reported that at least one member of their household became sick because of exposure. One-third of households surveyed by the Kanawha-Charleston Health Department and one-fifth of households surveyed by the U.S. Centers for Disease Control and Prevention experienced health issues they thought were attributable to the spill, that study also reported.
That study also reported that there were two "peak" times when residents reported health problems, one that corresponded with the Jan. 9 "do not use" order and another that matched the plumbing system flushing activities. Another study reported that "the large number of individuals with symptoms does raise the question of how to handle the situation more effectively in future incidents."
Whelton said the study results indicated that flushing hot contaminated water would result in greater chemical exposures than if hot water had been shut off and water had cooled. The new results also indicated that ventilation could help limit chemical levels in the indoor air from accumulating.
"The worst-case exposures seem to have been inside a room where little or no ventilation occurred, hot water was flushed, and chemicals accumulated in the indoor air," Whelton said.
State Public Health Commissioner Rahul Gupta, who was Kanawha County's top public health official during the water crisis, said that the new study "seems to be a fairly well-done paper with scientific findings applicable to future events."
"Inhalation risk of volatile substances should be kept in mind whenever dealing with such situations," Gupta said.
The Jan. 9, 2014, spill at Freedom Industries occurred just 1.5 miles upstream from West Virginia America's regional water intake, which provides drinking water to hundreds of thousands of people in Charleston and surrounding communities. The water company did not close its intake, and after contaminated water entered the treatment plant and the distribution system, authorities issued a "do not use" order that advised residents not to drink, cook with or bathe in their tap water.
Over the course of the next week, state officials and the water company lifted the water advisory as sampling from portions of the distribution system - taken from hydrants, not from people's homes - showed the chemical levels had dropped below a highly controversial emergency drinking water guideline put together by the CDC in the hours after the spill.
Residents were then advised that they could clear any remaining chemicals from their home plumbing systems by running hot and then cold water faucets throughout their homes for specific periods of time.
Whelton co-authored a previous study that criticized the specific flushing guidance, and co-authored another paper that reported that no scientific basis could be found for the flushing protocol residents were advised to use. Before issuing the flushing protocol, state officials rejected a recommendation from federal public health officials that residents be advised to flush their home plumbing systems until they could no longer smell the licorice-like odor of MCHM, the main ingredient in the Freedom spill.
Whelton said that changes to the flushing guidance - such as shutting off water heaters, opening windows and doors, or turning on window fans - likely reduced indoor air contamination levels for homes where he and a team of graduate students assisted residents.
"This personal safety guidance was not recommended to my knowledge by any agency that responded [to the spill]," Whelton said last week. "It should have been. The responders knew the chemicals in the drinking water were volatile and they didn't know what inhalation exposures would be toxic."
The day after the Freedom spill, the CDC quietly dropped plans to devise a "screening level" for what amount of MCHM in the air would be dangerous if inhaled. Agency officials cited the lack of data on MCHM's potential health effects, saying without such information it would be impossible to come up with a trustworthy number.
Many months later, the EPA came up with an air inhalation screening level for MCHM in October 2014 for use to monitor emissions during the demolition of the Freedom Industries site where the spill occurred. Even then, though, the EPA said their figure suffered from many of the same shortcomings caused by lack of adequate studies of MCHM: It was based on only one toxicity study, which examined pure MCHM, not the "Crude MCHM" mixture that Freedom used and spilled, and the study did not actually examine health effects of inhalation of the chemical.
The EPA inhalation guidance was based on data about rat exposure to MCHM and potential effects on the kidneys and liver.
On July 8, the National Toxicology Program at the U.S. Department of Health and Human Services issued what it called a "final report" on its investigation of the potential for MCHM exposure related to the chemical spill to make people sick. The agency's work was done at the request of Sens. Joe Manchin, D-W.Va. and Shelley Moore Capito, R-W.Va., and the Tomblin administration.
The NTP review has been billed as a definitive review of the spill's potential health effects and the state Department of Health and Human Resources has said the results show the state "took appropriate public health measures" after the spill.
The final federal report said that "most of the spilled chemicals had no effects in the studies that were performed." And when the chemicals did produce effects, those effects occurred "at dose levels that were considerably higher" that residents would have received from drinking contaminated water, the report said. NTP officials, though, conceded that their work did not look at inhalation exposures.
Reach Ken Ward Jr. at kward@wvgazettemail.com, 304-348-1702 or follow @kenwardjr on Twitter.