When last we heard from the three scientists on the C8 Science Panel, they were explaining to Wood County Circuit Judge J.D. Beane all their reasons for not yet issuing a finding about whether there is a “probable link” between exposure to the chemical C8 and adverse human health effects.
Well, the Science Panel has very quietly concluded three more of its many studies, and the findings are interesting and important:
— An association between increased levels of C8 in blood and increased alanine aminotransferase, or ALT, an enzyme that can indicate liver damage. The Science Panel said:
This association with ALT is unlikely to be due to chance, as it is highly statistically significant.
— Significantly increased rates of death among more highly exposed workers from DuPont’s Washington Works plant from kidney cancer and non-malignant kidney disease. The panel reported:
… The increased risk for the more highly exposed in relation to malignant kidney and non-malignant kidney disease could possibly be due to PFOA; the kidney is a site in the body where PFOA is found.
— Evidence of an association between C8 exposure and pre-eclampsia among pregnant women living in areas where DuPont’s chemical had polluted drinking water supplies. Unlike some previous studies, the Science Panel did not, however, find associations between C8 exposure and reduced birth weight. The panel said:
There are no other studies to support or challenge our finding of an association for pre-eclampsia. The association with pre-eclampsia is small but clearly present based on a variety of ways of examining exposure.
I haven’t yet seen any indication of the C8 Science Panel‘s plans for distributing the results of these three new studies to the public in the Mid-Ohio Valley. Lawyers for DuPont and the area residents who sued the company were briefed on the studies and have provided summaries of them to Judge Beane.
I’ve posted copies of those publicly available summaries here.
UPDATED: Very shortly after I posted this item on our blog, a press release showed up in my email inbox from Lisa Collins, on behalf of the C8 Science Panel. I’ve posted its contents below:
The C8 Science Panel submitted three reports to the Wood County Court this week, summarizing findings from three separate studies of information collected and tests performed on participants in the C8 Health Project and a follow-up study of workers at the DuPont plant where Teflon is manufactured.
The first report, investigating liver function markers, related C8 levels in 47,092 adults to three clinical markers of liver function. The three markers measured include bilirubin, ALT (alanine aminotransferase), and GGT (gamma glutamyltransferase). With all three markers, increased levels indicate lowered liver function.
While there was no direct association between increase of PFOA (C8) and bilirubin or GGT, there was an increase in levels of ALT , related to increasing PFOA.
However, the Science Panel advises caution in interpreting this link found between PFOA and a marker of liver injury, because of the cross-sectional design of the C8 Health Project. Both PFOA and the liver markers were measured at the same time and therefore we cannot be sure whether the PFOA exposure came before any changes in markers of liver function. Ongoing work is addressing whether liver disease may be affected by raised exposure to PFOA.
The next report submitted to the court detailed the mortality (death) rate of workers employed at DuPont. The group included 5793 workers employed there between 1948 and 2002. The Science Panel looked at 92 causes of death, and the only one significantly higher than the US population was mesothelioma, a rare cancer caused only by exposure to asbestos and unlikely to be related to PFOA. Significant trends of increased kidney cancer and nonmalignant kidney disease were seen with higher PFOA exposure, based on small numbers. There was no overall excess of kidney disease compared to the US population.
The panel noted that mortality studies are not the best way to study many diseases which may not be fatal. Therefore they have conducted an additional worker study based on disease occurrence rather than deaths, and those results will be available in the first half of 2012.
In the third report, the group analyzed pregnancies of women occurring between 1990 and 2005, and studied the relationship between PFOA exposure around the time of pregnancy and the risk of miscarriage (loss of pregnancy before 20 weeks), stillbirth (loss of pregnancy after 20 weeks), preeclampsia (a condition involving high blood pressure and leakage of protein into the urine during pregnancy), preterm birth (early delivery), term low birth weight (an indication of reduced growth), and birth defects (abnormalities in the infant).
No association was found between PFOA levels and miscarriage, stillbirth, preterm birth, low birth weight or birth defects. There was a small but clear connection between preeclampsia and higher levels of PFOA. There are no other studies to support or challenge this finding. The group will be obtaining additional information on preterm birth and birth weight from ongoing analyses of health department birth records for the study area. These new records will be combined with the current records and other new data before a final assessment about pregnancy outcomes is made.
The C8 Science Panel was chosen to determine whether a probable link exists between C8 and any human disease as part of a class action settlement of a lawsuit involving releases of the chemical known as C8 from DuPont’s Washington Works in Wood County, West Virginia.
The Science Panel is made up of three scientists from universities in London, Atlanta and Providence, Rhode Island. The three panelists were agreed upon by both DuPont and the plaintiffs. They are Dr. Tony Fletcher, Dr. Kyle Steenland, and Dr. David Savitz. More information on the panel and its work can be found here.