VIENNA - The C8 Science Panel reported Thursday that it had found no link between C8 and C8S, chemicals used in the manufacturing of Teflon, and miscarriages and preterm births and a weak, inconclusive link between the chemical and preeclampsia and immune-system markers.
The science panel, which was created as part of the C8-class-action lawsuit settlement against DuPont, is made up of three scientists from universities in London, Atlanta and New York, and works to determine if C8 is linked to any human disease. The panel reported its preliminary findings in the ongoing study Thursday during a press conference at Grand Pointe Conference Center in Vienna.
The C8 Science Panel has completed a new evaluation of the relationship between C8 (also known as PFOA) and C8S (also known as PFOS) in the blood and reproductive health based on data from Mid-Ohio Valley residents who participated in the C8 Health Project in 2005 and 2006.
David Savitz, member of the C8 Science Panel, speaks at a press conference Thursday about the ongoing C8 study.
Photo by?Dave Payne Sr.
David Savitz of the Mount Sinai School of Medicine said no connection was found between miscarriages and C8 or C8S. There was a slight increase of preeclampsia, a pregnancy complication with high blood pressure and protein in the urine, among those who were over the 50th percentile in amount of exposure, but the rates of preeclampsia were still within normal levels. There was a similar increase in those over the 50th percentile for low birthweight, but those were also within normal levels, Savitz said.
Higher levels of C8 and C8S were not found to be related to miscarriage or preterm birth. There were some weak relationships between both C8 and C8S with preeclampsia and birth defects in the infants, but the evidence to suggest that risk increases with greater exposure is not consistent, officials said.
"The results for preeclampsia and birth defects were more suggestive of a possible relationship for both PFOA (C8) and PFOS (C8S) slightly stronger for PFOS," the panel's report says. "Even for these outcomes, the relative risks were only modestly elevated and none showed clear increasing risk with higher exposure. Overall, the data provide little support for PFOA or PFOS being related to pregnancy outcome, with some uncertainty regarding preeclampsia and aggregated birth defects."
There was a very slight increase in the number of birth defects at the highest levels of C8 exposure, but the panel said the numbers were not significant enough to draw conclusions.
"Congenital heart defects were the single most common type of birth defect," the report says. "However, with only 13 heart defect cases numbers were too sparse for adjusted analyses."
He said the preliminary findings were not sufficient for drawing conclusions and that the study would soon be looking at additional pregnancies.
The analysis focused on women who reported pregnancies within a five-year period before the project began and lived in the same water district during that time, so the levels of C8 in blood would be similar to what they were during the pregnancies.
DuPont spokesman Dan Turner said it's important to remember that the study is still in its early stages.
"The increases suggested were still all within normal levels," he said.
Tony Fletcher, of the London School of Hygiene and Tropical Medicine in London, said the study found a slight change in immune markers, a downward trend in immunoglobulin A, suggesting immune-system suppression and an upward trend of an indicator of auto-immune disease. There was also a downward trend in a marker of inflammation, Reactive Protein CRP, an indicator of heart disease.
The differences were very slight and created a very weak statistical association between the chemical and immune markers. The panel will take further blood samples and additional interviews to gather more data, Fletcher said.
Joe Kiger, a lead plaintiff in the class-action lawsuit, said people remain concerned during the long study process.
"I know this all takes time, but people are very concerned," he said.
Kyle Steenland, of Emory University in Atlanta, said that previous estimates for the half-life of C8 in blood levels were 3.8 years, but preliminary results of the panel's studies on people in the Lubeck and Little Hocking water systems after C8 filters were installed were 2.3 years. At that rate, about 95 percent of C8 would be removed from the blood 10 years after exposure, although the half-life varied from 1.5 years to 4.6 in those studied, he said.
"We can't tell everything from the first year," Steenland said. "This is an estimate from the first year and is part of an ongoing study."
Steenland said the C8 filters in the public water systems were working and had effectively reduced C8 concentrations. He said more precise estimates of the half life of the chemical will be available when the study is completed in 2012. Two more blood samples will be drawn from participants, one this summer and another in 2011.
The report is available at the panel's Web site, www.c8sciencepanel.org.