C8 exposure has been linked to a variety of health problems, including liver damage, immune problems, developmental abnormalities, birth defects and high cholesterol.
The levels of C8 in the blood of those studies exceeded the average general population's exposure by 500 percent, because of the exposure to contaminated drinking water near the DuPont plant.
But the study also looked at blood levels of a related PFC known as PFOS. Researchers found a stronger association between PFOS and the onset of menopause. And, the levels of PFOS in the women studied were similar to the concentrations found in the blood of the general U.S. population.
"The source of elevated PFOA levels was primarily contaminated water, but the source of PFOS was primarily sources in the ambient environment," the study said. "This means that the effects of PFOS in this sample are probably typical for those in the population as a whole."
Researchers said that it is possible that PFC concentrations are higher in post-menopausal women because they are no longer losing blood.
"Menstrual flow eliminates some of the PFC in blood, and because blood is replaced faster than the toxicant, concentrations measured in menstruating women could be lower than those who aren't menstruating, even with the same exposure level," the study said. "Thus, the argument could be made that some of the significance associated with an increased risk of menopause associated with increased PFC might be due to reverse causation, i.e., the disappearance of menses causing increases in PFC concentrations rather than an increase in PFC causing early menopause."
But researchers said that even if this "reverse causation" is at work, the results "would still be cause for alarm because it would imply that increased PFC exposure is the natural result of menopause or hysterectomy."
"Regardless of mechanism, the results have serious clinical implications for women's health," the study said. "The additional question that needs to be asked is whether these increased exposure levels are more adverse in an aging body whose systemic defenses may be less robust."
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.