PARKERSBURG, W.Va. — “Weak relationships” between exposure to C8 and pregnancy complications and birth defects have been identified by the C8 Health Panel, but it is not believed that C8 causes miscarriage, premature births or low birth weight.

The Science Panel, formed to determine if there is a link between exposure to the chemical and any human disease, announced results of an evaluation of the relationship between C8 and C8S in the blood and reproductive health. The analysis is based on recent pregnancies among Mid-Ohio valley residents who participated in the 2005-2006 C8 Health Project.

A summary of the study has been filed with the Wood County, W.Va. court as required by settlement of a class action lawsuit in 2004.

Women who participated in the C8 Health Project were asked about each of their pregnancies, indicating whether they had a miscarriage, preclampsia, — a complication of pregnancy with high blood pressure and protein in the urine — low birth weight, pre-term birth, or birth defects.

“Higher levels of C8 and C8S were not found to be related to miscarriage or pre-term birth,” the report released Thursday said. “There were some weak relationships between C8 and C8S with preclampsia and birth defects in infants, but evidence to suggest that risk increases with greater exposure is not consistent.”

“Because there is some inaccuracy in the reports on pregnancy, and the number of pregnancies that could be included in this stage of the analysis was limited, the panel could not draw conclusions regarding whether either of these chemicals were associated with problems in pregnancy.”

The panel will conduct a more comprehensive study of pregnancies, including an examination of years prior to the C8 Health Project, and including more complete data on past exposures from another panel-run project. An additional Science Panel study will be conducted on all births in the area, using birth certificates.

The release of study results Thursday provided information from two additional investigations. The panel also reported a first preliminary estimate of the time it takes the body to clear C8 from its system once the source of the chemical has been filtered.

The Science Panel has been measuring C8 serum concentrations over time for 200 customers in the Lubeck, W.Va. and Little Hocking Water Association water systems to determine how fast the chemical is removed from the body after water filters have been installed and C8 exposure is reduced.

“Half life” refers to the time it takes the body to clear half of its C8. Two groups were recruited in each water system: Those reporting primary use of public water for drinking at home, and a smaller group drinking bottled water at home.

The estimated average rate of decrease in serum C8 after filtration for the four groups tested is 26 percent per year, meaning C8 can be cleared by 50 percent in 2.3 years.

“For people with levels of those in our study, about 95 percent would be removed from the body 10 years after exposure ended,” the study said.

The panel has also determined that immune markers, naturally-occuring chemicals in the blood, indicating how well the immune system can fight off disease, lie in normal ranges among its study participants.