Researchers also found a proportionately higher concentration of free BPA—as opposed to the conjugated forms modified by the body for elimination—further showing that in fetuses the ability to eliminate the chemical from the body is not the same as in adults.
"The general message from our research is that people have to be cognizant of the fact that the adult body may be able to deal with a particular exposure but a developing fetus may not," said Muna Nahar, doctoral student in the School of Public Health's Department of Environmental Health Sciences and first author on the paper.
Previous animal studies have associated BPA with breast and prostate cancer, and reproductive and behavioral abnormalities. Some research on effects to human health has tied BPA to cardiovascular disease, miscarriage, decreased semen quality and childhood behavioral issues. The chemical also may impact metabolism, diabetes and obesity, although more studies are required to determine its effects.
Prior research on BPA—a chemical used in many consumer products, including plastic bottles and metal food and beverage cans—has measured concentrations of the chemical in urine. About 95 percent of those who have been tested in a nationally representative health survey study show some level of BPA, but the research to date had yet to firmly establish the presence of the chemical in tissues.
Understanding the internal dose is essential to determine adverse effects on health, the researchers say. BPA can reach the body through ingestion, inhalation and by contact with the skin.
Nahar and colleagues Dana Dolinoy of the U-M School of Public Health and Chunyang Liao and Kurunthachalam Kannan of the Wadsworth Center at the New York State Department of Health studied the livers of 50 first- and second-trimester fetuses, using high-performance liquid chromatography and mass spectrometry. They found wide variances in how much BPA was present in livers, with some fetuses showing high levels of exposure.
"The finding of free BPA in fetuses is significant," said Dana Dolinoy, the John G. Searle Assistant Professor of Environmental Health Sciences and senior/corresponding author of the study.
After measuring a three-times-higher concentration of free BPA than the conjugated forms in the fetal livers, the researchers then examined the enzymes responsible for metabolizing the chemical and compared them with those at work in adult male and female livers.
"Our research shows that the argument that it's so rapidly metabolized is not true in fetuses," Dolinoy said.
The study appears online in the Journal of Biochemical and Molecular Toxicology, which in early 2013 will publish a special print issue focusing on the National Institute of Environmental Health Sciences Outstanding New Environmental Scientist Award (ONES) projects. Dolinoy was awarded a five-year ONES grant in 2009 for the project titled "In Utero Exposure to Bisphenol A: Effects on the Fetal Epigenome."
Dana Dolinoy: www.sph.umich.edu/iscr/faculty/profile.cfm?uniqname=ddolinoy
Muna Nahar: http://research.sph.umich.edu/person.cfm?deptID=2&groupID=32&ownerID=478
School of Public Health: www.sph.umich.edu/index.htmlView a Risk Bites video that explains BPA: http://youtu.be/219JRH3dEwg
Laurel Thomas Gnagey | Newswise
Understanding the Body’s Response to Worms and Allergies
24.04.2015 | University of Manchester
Caring for blindness: A new protein in sight?
22.04.2015 | NSERM (Institut national de la santé et de la recherche médicale)
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
24.04.2015 | Materials Sciences
24.04.2015 | Materials Sciences
24.04.2015 | Health and Medicine