Many newborns are exposed in their earliest days to bisphenol A (BPA) and lots of other chemicals, the world is all chemical, but BPA has been the subject of more scrutiny than most because it is ubiquitous. Due to that, environmental advocacy studies have claimed there is probably risk to adults and newborns, while more neutral science says that it is detectable but not harmful.

The U.S. Centers for Disease Control and Prevention has found that more than 92 percent of Americans ages six and older have detectable BPA in their bodies, most likely through the consumption of food stored in packaging made from it. The question is whether or not it has been harming them. In some animal studies, BPA in very high amounts was shown to mimic the sex hormone estrogen in the body and is claimed to have developmental effects on the brain, lung and reproductive organs. 

Because newborns have less mature livers, some claimed they would have a difficult time processing the chemical and that could mean increased health risks. Certainly a valid hypothesis and due to the precautionary principle it was banned in baby bottles and sippy cups in 2012 by the Food and Drug Administration. BPA is still in wide use because the FDA has repeatedly concluded that it is safe - except for animals in environmental toxicology studies who get it at levels far outside possible human consumption.

For a new study, conducted between Dec. 2012 and August 2013, researchers collected urine samples from 44 full-term babies, once between three and six days of age and again between seven and 27 days of age. They were looking for two forms of BPA: free BPA and BPA glucuronide. Free BPA is the chemical as it appears in consumer products, and BPA glucuronide is what remains after free BPA is metabolized by the body. The researchers found no free BPA in the urine samples, while more than 70 percent of the samples contained BPA glucuronide. BPA glucuronide is biologically inert and therefore considered harmless to the body.

Scientists were concerned that BPA would behave similarly in the body to bilirubin, a biological byproduct created by the breakdown of red blood cells. Healthy livers turn bilirubin into bilirubin glucuronide, a very similar process to the one BPA follows, which can then be excreted. Routinely, babies may have trouble with this process in their earliest days, resulting in jaundice in most newborns.

 "Even though we've removed BPA from bottles, this work shows infants are still exposed to it," says study leader Rebecca Massa Nachman, PhD, MPH, a post-doctoral fellow in the Johns Hopkins Bloomberg School of Public Health's Department of Environmental Health Sciences. "But the good news is that our study also shows healthy newborns are better able to handle that exposure than we thought."

The group found no difference between BPA glucuronide levels in infants who were formula fed and those who were breastfed. 51 percent of the babies were fed formula exclusively, 28 percent were only fed breast milk and 21 percent consumed a combination of the two.

Studies have shown that powdered baby formula contains no BPA, while breast milk does. Among children and adults, food is believed to be the primary source of BPA found in the body, even though it is also found in cash register receipts, refillable water bottles, the lining of water pipes and even in dust.

Citation: "Urinary Free Bisphenol A and Bisphenol A Glucuronide Concentrations in Neonates in Baltimore, Maryland", Rebecca M Nachman, PhD, MPH; Stephen D Fox, BS; William C Golden, MD; Erica Sibinga, MD, MHS; John D Groopman, PhD and Peter S Lees, PhD. This study was supported in part by the Johns Hopkins Center for a Livable Future-Lerner Fellowship, the Wendy Klag Memorial Fund, and by grants from the National Institutes of Health's National Institute of Environmental Health Sciences (P01 ES006052, P30 ES003819 and training grant T32 ES007141) and the National Cancer Institute (P30 CA006973 and contract N01-CO-12400).