C8 and related chemicals used in nonstick pans and stain-resistant fabrics have been found in human breast milk, according to the first major U.S. study to examine breast-feeding as a possible exposure route.
Perfluorinated compounds, or PFCs, were found in all of the 45 human breast milk samples tested in the new study, published in the peer-reviewed journal Environmental Science and Technology.
Toxicologist Kathleen Arcaro of the University of Massachusetts Amherst and other researchers tested the milk as part of Arcaro’s ongoing investigation of links between environmental exposures and breast cancer.
It’s one of several sources of contamination
“While nursing does not expose infants to a dose that exceeds recommended limits, breast milk should be considered as an additional source of PFCs when determining a child’s total exposure,” Arcaro said in a news release issued by her university.
In West Virginia, C8 is a major issue because the water supplies for thousands of Parkersburg-area residents have been contaminated with the toxic chemical.
Around the world, researchers are finding that people have C8 and other PFCs in their blood in low levels. Evidence is mounting about the chemical’s dangerous effects, but U.S. regulators have not set a federal standard for emissions or human exposure.
Scientists are still sorting out how humans are exposed, but previous studies have examined Teflon pans, food and food packaging, and household dust as potential routes.
One recent study found that C8 can move through the air more readily than previously thought, and suggested that the chemical could become concentrated on ocean waves and lofted into the air.
In humans, studies have found that PFCs can be transferred from pregnant women to their babies through blood. And two of three recent studies of the issue have linked exposure to these chemicals to birth outcomes in humans, including low birth weight and small head size.
In China and Sweden, previous studies found that PFCs could also be transferred from mother to baby during breast-feeding.
But despite a higher concentration of PFCs in the blood of the general population here, only one previous study of breast milk – using only two samples – examined the issue in the United States.
In the new study, milk samples were collected in 2004 from 45 nursing mothers in Massachusetts and analyzed for C8 and eight related chemicals.
Perfluorooctane sulfonate, or PFOS, was found in the highest concentrations, followed by perfluorooctanoic acid, or PFOA. PFOS has been used to make stain-resistant fabrics, while PFOA, also known as C8, was used to make Teflon and other nonstick coatings.
On average, each liter of milk contained 131 billionths of a gram of PFOS and 44 billionths of a gram of PFOA, the study found.
Researchers estimated that, at those levels, an infant would consume less PFCs through breast milk alone than the levels recommended by the U.K. Food Standards Agency Committee.
But other possible exposures for infants remain unclear, and scientists cautioned that mothers should also consider the nutritional and immune system benefits from breast-feeding.
Concentrations increase in first six months of nursing
Milk from mothers who were nursing for the first time was also studied to see how PFC concentrations changed over time. Total PFC concentrations and the concentration of PFOS increased during the first six months of nursing, the study found.
“This may be related to increased food intake to meet the energy demands of nursing, and changes in food consumption patterns in nursing mothers,” Arcaro said. “In a Canadian study, diet was shown to contribute 61 percent of a person’s total daily intake of PFCs.”
The study said the findings also suggest that PFOA and other PFCs “are excreted in breast milk and that the concentrations of PFCs in milk decrease with a history of previous breast-feeding.”