CDC based its ‘safe’ chemical level on two-week exposure
CHARLESTON – When federal officials decided what chemical levels West Virginians could safely consume in water tainted by a January spill, their standard assumed people would be exposed for two weeks, not 100-plus days.
Months later, Centers for Disease Control and Protection officials see no reason to adjust a chemical benchmark they quickly created off limited lab rat research. However, a local health official argues the CDC needs to account for ongoing chemical exposure, even if it’s minimal.
Until Democratic U.S. Sen. Joe Manchin asked last week, CDC never revealed how long its safety mark assumed everyday contact with chemical-laden water. For months, the CDC said the level accounted for the “short-term,” but hadn’t conveyed a firm timeframe. Gov. Earl Ray Tomblin told The Associated Press Monday he wasn’t informed what “short-term” meant.
Richard Denison, a scientist with the Environmental Defense Fund, cautioned that even a new, more protective long-term standard would have the same flaw: no one knows exactly how much people were exposed to the chemical, and little toxicity data is available on long-term implications.
For four to 10 days, starting Jan. 9, 300,000 people in nine counties faced a tap-water ban until the regional water plant and various hydrants met the CDC’s mark. Only 11 people’s homes were tested, all more than a month after the spill.
In tests late last month, chemical traces well below the safe level were leaching off the water plant’s filters and flowing to people’s home taps. West Virginia American Water started changing the first of its contaminated filters April 1, but the full slate of 16 might not be replaced until late May. Small chemical levels will keep entering the water system until then, researchers say.
The longer someone is exposed to a chemical, the lower the safe level should be, local health officials like Dr. Rahul Gupta of Kanawha-Charleston Health Department have argued.
CDC spokeswoman Bernadette Burden said there’s no reason to believe anyone will have adverse health effects from trace chemicals in their taps, including at previous lab detection limits that were 100 times lower than the safe drinking mark. Comparatively, the chemical found leaving the water plant last month was 2,000 times lower than the safe standard.
Gupta said there is evidence, and the CDC already has it.
Chemical levels at the water plant dipped to 250 times lower than the safe mark six days after the spill, and two days after some people flushed their homes. The following three days, 134 people went to the emergency room and seven people were hospitalized with associated symptoms – rashes, diarrhea, vomiting, skin and eye irritation, headaches and nausea. More than 50 went to Kanawha and Putnam health providers.
The CDC has the reports detailing more than 533 ER visits and 26 people hospitalized in the two weeks following the spill. But the agency hasn’t offered review and guidance yet. Gupta said the impact was much larger, estimating about 92,500 felt some health impacts from the spill and only 40 percent went to a doctor. A state-funded research group, nicknamed WV TAP, came up with a similar number, 108,800.
“I hope the CDC would take another look at the data and the facts on the ground,” said Gupta, a proponent of monitoring the population’s long-term health.
Research by WV TAP also calls the CDC’s standard into question.
The group created a standard that was eight times more cautious about contact with the main spilled chemical. The scientists assumed 28 days of exposure, accounting for skin contact and breathing in the licorice-smelling material, in addition to consuming it in water, which was the CDC’s sole focus.
The CDC says it doesn’t know how WV TAP conducted its study, and would evaluate it when methodology is publicly available.