C8 Science Panel Newsletter
C8 Science Panel Quarterly Newsletter #2
1. Science Panel studies update
1. Science Panel studies update
The Science Panel is running a series of related epidemiologic studies to gather more evidence to allow us to identify any links between C8 and diseases. You may visit the website to review the updated status of each study.
During the last quarter data collection was completed in two studies - the Study of C8 and Neurobehavioral Development among children from the C8 Health Project, and phase 1 of the Short Term Follow-up Study of C8 and Immune, Liver, Kidney and Endocrine Function. Initial results from this survey indicate that both C8/PFOA and PFOS have fallen by more than half in the serum of participants in the 4 to 5 years since the C8 Health Project survey.
The second round of phone interviews in the Community and Worker follow up studies started and will continue until December.
The Science Panel presented our work in progress at the following scientific conferences: 2010 Annual Meeting of the International Society for Environmental Epidemiology in August; Dioxin 2010 meeting on Persistent Organic Compounds in September.
2. Press and publicity
Panelist Tony Fletcher met the Press at the end of September 2010 in Parkersburg to announce the first results of investigations into age of puberty and C8/PFOA and PFOS.
A summary of the results was submitted to the Wood County Court which is overseeing these studies, in the form of a status report “Patterns of age of puberty among children in the Mid-Ohio Valley in relation to Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS). C8 Science Panel, Sept 30 2010.” which can be seen on the C8 Science Panel website at:
The full press release can be found on the website at:
From the press release:
New results from study on C8 exposure and delayed puberty in children
A relationship has been found between exposure to the chemical commonly known as C8 and delay in the onset of puberty. Dr. Tony Fletcher, a member of the C8 Science Panel 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 a chemical known as C8 from DuPont's Washington Works in Wood County, West Virginia, presented results from a recent study showing delayed puberty related to perfluorooctanoic acid (PFOA or C8), and perfluorooctane sulfonate (PFOS).
This study examines the relationship between levels of two polyfluoroalkyl compounds (PFCs), including PFOA and PFOS, measured in the blood serum of child participants in the C8 Health Project (3,076 boys and 2,931 girls), and the chance of reaching puberty. Results are presented as the number of days’ delay in the average age of puberty by exposure group. All participants had been residents for at least a year in the six water districts contaminated with PFOA in the Mid-Ohio Valley.
Determinations were made as to whether a young person had reached puberty using the test results of male and female hormones which change at puberty and, for the girls, also asking whether menstrual periods had begun. Results presented by Dr. Fletcher indicated that the association with pubertal delay was stronger for PFOS, and that there was a delay of about six months for boys and four months for girls when higher exposure groups were compared with lower PFOS exposure groups. For PFOA, there was a delay of about four months in puberty for girls and probably not an association for boys, although this could not be ruled out.
Dr. Fletcher commented, “We did find an association between delayed puberty and exposure to PFCs, but these results need to be interpreted with caution. Other explanations need to be considered; in particular that the bodily changes associated with puberty could have led to changes in PFOS and PFOA levels in the children’s blood serum, which then show up as these associations. Another possibility is that some other factors might be leading to both changes in the age of puberty and difference in PFC uptake. We looked at other potential explanations where we had the data, including reported smoking, alcohol intake, obesity and household family income, and in no case did taking them into account make any difference to the findings. But there may be other such causes, and further research is needed.”
These results are summarized in a Status Report submitted to the Wood County Court in West Virginia – “Patterns of age of puberty among children in the Mid-Ohio Valley in relation to Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS). C8 Science Panel, Sept 30 2010.”
The previous issue of this newsletter can now be found online in the C8 Quarterly Newsletter Archives. Catch up with the past news at:
4. New publications
The following journal articles are publications on C8 with input from C8 Science Panelists appearing in journals (online or in print) in the last 3 months.
Private drinking water wells as a source of exposure to PFOA in communities surrounding a fluoropolymer production facility.
Accumulation and clearance of PFOA in current and former residents of an exposed community.
Perfluorooctanoic acid, perfluorooctanesulfonate, and serum lipids in children and adolescents: Results from the C8 Health Project.
Epidemiologic evidence on the health effects of perfluorooctanoic acid (PFOA).
5. Quarterly focus
Here we summarize work in progress in the Science Panel work following up adults in the Mid-Ohio community: residents in the water districts and workers/retirees from the Dupont Plant
From Kyle Steenland:
We continue to seek the help of participants in past C8 study efforts. If you are part of the interview/study group, we encourage you to continue to participate. Your assistance is essential to the most complete picture of the potential impacts of C8.
The Community and Worker Cohort Studies are gathering new data on the incidence of disease in the local population. These studies will be particularly informative because they will provide direct insight on rates of disease following exposure, in relation to exposure measured before these diseases started. Such information is very important for our final determination of whether there is a probable link between any specific disease and C8. We will use the data collected in these studies to investigate whether there has been more disease among those with higher C8 levels in their blood compared with those with lower levels. Blood levels of C8 are available from measured blood levels at the time of the C8 Health Project in 2005-2006, and levels at other times will be estimated based on people’s area and duration of residence, as determined in a major effort by our exposure reconstruction team.
We are currently collecting further information from community and worker participants in these studies. We have already completed a first round of interviews in 2008-2009, where we were very pleased with the good participation. In round 1 about 75% of the target population of 45,000 people participated. Most people participated (over 90%) if we were able to contact them. But significant numbers have moved out of the area and could not be located.
We are collecting reports on a wide range of disease, including heart disease, cancer, stroke, liver disease, thyroid disease, auto-immune disease, among others. When people report any of these diseases, we ask permission to obtain their medical records from their doctors or hospital. This checking against medical records is to confirm the self-reported disease, so we can be sure to use the correct diagnosis and dates in the data analysis. People have been very responsive in sending us these permissions, but we still need more help. To date we have received permission from about 75% of those who have reported disease. The permissions must be signed and mailed in separately from the interviews themselves, making their collection difficult.
The second round of interviews will gather data on the most recent disease occurrence. We have completed interviews with about 50% of the target population in round 2. People who were not interviewed in round 1 can now be interviewed in round 2. We hope to finish round 2 interviews by December. The interviews, which typically last 30 minutes, are done either on the internet or by phone and we provide $20 in the form of Walmart gift cards in compensation for people’s time.
Then the data must be cleaned and we must seek medical records for self-reported disease. In the first round approximately 50% reported some disease for which we are seeking medical records, while in the second round about 25% reported some disease occurring in the approximately 2 years since the first round. We expect final data on medical records should be available in mid-2011.
Some people ask why we had to go to all this effort, since the C8 Health Project had already asked about disease in 2005-2006. While the C8 Health Project data is very useful, it related to diseases which happened before the interviews and there is limited value in linking these to C8 exposure measured after the disease occurred. The Science Panel studies have been designed to address this limitation and we have been busy gathering these pieces in our interview surveys, medical record validation, and historical exposure reconstruction.