By PAMELA BRUST
LITTLE HOCKING - Residents in Ohio communities with the
highest levels of C8 in their drinking water and air may have
significant concentrations of C8 in their blood, according to
a draft model by DuPont. The concentration levels could be
double the average amount of C8 found in DuPont employees who
directly work with the unregulated chemical at the local
According to documents filed in an ongoing class-action
lawsuit, by October 2001, DuPont had a draft model to relate
C8 exposures through air and drinking water to estimates of C8
concentrations in human blood. The model estimates long-term
C8 exposure from levels such as those detected in water and
air in Ohio could result in blood levels twice the average of
that reported in DuPont employees who worked directly with C8,
or 1,530 parts per billion.
Court records show DuPont told its employees in 1987 an
"acceptable level" of C8 in the blood was 500 ppb. Employees
with more than 50 percent of that level should be removed from
further exposure. DuPont's model indicates area residents
likely will have C8 in their blood at levels more than eight
to 16 times higher than DuPont's 250 ppb acceptable level.
Employees also were provided with protective clothing,
equipment and medical monitoring.
In a Feb. 3 letter to United States and Ohio Environmental
Protection agencies, Cincinnati attorney Robert Bilott, one of
the plaintiffs' lawyers in the suit, informed EPA officials of
the DuPont models. He asked the agencies to respond to
continuing C8 exposure in the community.
Washington Works Plant Manager Paul Bossert said DuPont has
shared information regarding C8 with employees since 1978,
when it first learned the chemical remained in the body for
some time after exposure. Bossert noted in more than 50 years
of use by DuPont and others, there have been no known adverse
human health effects associated with C8, used in the
manufacture of Teflon.
Information from the company states the chemical is removed
before the Teflon is applied to cookware, clothing and other
products. Under an agreement with the EPA, DuPont was to
reduce C8 emissions by 50 percent by 2000. In March 2001, the
company installed a filter and carbon treatment system at its
facility to remove C8 from the wastewater stream.
Robert Rickard, director with DuPont Haskell Laboratory,
told The Parkersburg News and Sentinel data based on employee
blood confirmed the model "significantly over-estimates
potential blood levels in the community because it was based
on a simple model that is severely limited because it lacks
specific data on the absorption and elimination of C8 from the
"There is ongoing research to determine whether it is
feasible to accurately model theoretical blood concentrations
of C8 resulting from air or water exposure. This research plan
has been shared with the EPA and is scheduled for completion
later this year," Rickard said.
Rickard said Thursday he requested the models be generated
by lab scientists in 2001.
"They are mathematical models and don't contain specific
information relative to C8 and should not be used in this
manner. It is very misleading."
To help visualize 1 ppb, Rickard said it can be compared to
one second of time every 33 years. The highest C8
concentration in samples from the test wells was 37.1 ppb last