C8 Levels In Maternal Blood Do Not Affect Preterm Birth
A study conducted by researchers at the University of Pennsylvania School of Medicine and colleagues, and published in Reproductive Toxicology, found that maternal exposure to C8, a chemical used in the manufacture of non-stick surfaces, was not associated with either lowered birth weight or increased risk of preterm birth in Little Hocking, Ohio area residents.
These findings are based on an examination of the vital records of newborns in Washington County, Ohio who were exposed to significant amounts of C8 through residential drinking water. Although C8 was not associated with lowered birth weight or increased risk of preterm birth, the authors noted that additional research is still required to confirm these findings and to investigate other potentially adverse health effects of C8 on fetal and childhood development.
A previous study by the same group, released in 2005, had shown that blood C8 levels in Little Hocking public water users were approximately 80 times those observed in the general U.S. population. The current study was performed because studies from other institutions had suggested that mothers with significantly lower C8 levels as compared to those found in the Little Hocking residents may be at risk for delivering newborns with lowered birth weights.
C8 is the commonly used name for perfluorooctanoic acid, or PFOA – a chemical used in the production of fluoropolymers. This chemical is used to manufacture non-stick surfaces for cookware as well as to make clothing, carpeting, and other products resistant to grease, water, and stains. According to manufacturers, C8 is not present in the final products. However, C8 is very persistent in the environment and is not biodegraded. Once inside the human body, it is very slowly eliminated.
Since being found in Little Hocking water, C8 has been found to contaminate other water supplies in the Ohio Valley, as well as in Minnesota, New Jersey, and other states, in addition to other countries such as Germany.
C8 has now been removed from the public water supply in Little Hocking through a new water treatment facility. Most residents took advantage of an offer of free bottled water following the release of previous studies; however, prior to the implementation of these interventions in September 2005, Little Hocking Water District residents were found to have the highest blood C8 levels ever recorded in a general population. When researchers compared the birth weights and gestational ages of newborns in the Little Hocking Water District prior to September 2005 and compared them to the birth weights and gestational ages of unexposed control newborns, no significant differences were observed.
“Birth weight and gestational age distributions for PFOA-exposed and unexposed populations were virtually identical,” said co-author Edward Emmett, MD, MS, Deputy Director, Center of Excellence in Environmental Toxicology at Penn. More importantly, the risk of low birth weight (defined as a birth weight of less than 2500 grams/5 pounds, 8 ounces) and the risk of premature birth (defined as less than 37 weeks of gestation) between populations were not statistically different. Both low birth weight and premature birth are risk factors for the development of chronic diseases later in life including coronary heart disease, hypertension and type-2 diabetes.
Although C8 was not associated with lowered birth weight or increased risk of preterm birth, Emmett noted that additional research is still required to confirm these findings and to investigate the other potentially adverse health effects of C8 on fetal and childhood development.