Scientists in Sacramento and Davis at the National Primate Research Center at the University of California, Davis have announced a new study today on the fetuses of pregnant rhesus macaque monkeys which has shown that exposure to the chemical bisphenol A, or BPA, led to changes in their lungs that increased the potential for developing asthma, according to the August 18, 2013 Sacramento Bee news article by Edward Ortiz, "UC Davis study links chemical BPA to asthma ." The study, conducted at UC Davis is part of a larger study designed to look at how BPA affects the endocrine system of macaques.
The results of the lung research – considered the first of its kind – adds another layer to the ongoing debate on the effects of BPA, which is found in many products, including on the inside of cans, in plastic bottles of many types, on cash register receipts handled daily by cashiers (some of whom may be breastfeeding where the BPA may get into their breast milk), and in older plastic baby bottles. Numerous studies have found a link between BPA and effects on hormonal systems and fetal development.
Many manufacturers have already taken the BPA out of toddler's sippy cups or various baby bottles. Locally, in 2013, California banned the manufacture and sale of all bottles and cups that contain detectable levels of BPA. Yet you have the chemical industry still insisting that BPa is safe due to the lower levels of BPA that humans are exposed to daily from plastics and air pollution. You have studies of newborn babies with BPA already in their blood. See the articles, "90 Percent of Cord Blood from U.S. Babies Tests Positive for BPA" and "232 Toxic Chemicals found in 10 Babies."
What's different about the new UC Davis research is that the current study has been done using monkeys. In the past, other studies were done using rodents
Fetal development in macaque monkeys is similar to fetal development in human babies. So the effects would be closer to what happens to humans when exposed before birth to BPAs from the environment such as utensils. The animals were exposed to BPA during the third trimester, which happens to be the critical window of development when it comes to how BPAs effect the body and health.
Female macaques between 6 and 13 years of age were used in the study. After mating and conception, the macaques received an implant that gave them dosages of BPA to equal the level of BPA found in human blood, according to the Sacramento Bee news article. The study is very significant to science because it can show scientists how BPA plays a role in the development of asthma. Sacramento as well as the entire Central Valley of California has a high rate of asthma and allergies. On the other hand, exposure to BPA and any link to asthma or allergies still has not been proven in human beings.
Asthma rates around Sacramento and the Central Valley
The Sacramento Bee reports a 2009 survey which found that many Central Valley counties have much higher rates than the state average, such as Yuba at 23.9 percent, Colusa at 23.7 percent and Fresno at 19.2 percent. What UC Davis scientists are studying are the effects of BPA on lung development in fetal development. You have many studies on fetal brain development, but fewer on lung development. There's also a larger study on the effects of BPA on macaque fetuses.
BPA also disrupts ovary development before birth. Before babies are born, even the number of eggs they will have in their reproductive life is determined before female babies are born. The study revealed how some primates had shown effects of BPA in their ovaries and/or mammary glands. Other monkeys showed effects in their brain or lungs. Scientists study their individual differences as to how the BPA changed their development. Also UC Davis has a study, you may wish to read about, "BPA Affects Lung Development."
How BPA Affects Lung Development
Collaborative efforts are adding critical information to understanding effects of BPA. BPA (bisphenol A), is used in the manufacturing of various plastics and food packaging, consumer products, some paper receipts, and medical devices. It is controversial because it exerts weak, but detectable, hormone-like properties which can mimic estrogen and may lead to far-ranging negative health effects including increased cardiovascular disease and diabetes in adults, increased cancer rates, including breast cancer, neurological difficulties, and hormonal and reproductive issues in both sexes and at all stages of life. Check out news about the latest study at UC Davis on BPA and fetal lung development, "BPA Affects Lung Development."
Recent results from research at the California National Primate Research Center (CNPRC) have shown that fetal BPA exposure during a critical window of susceptibility in the third trimester, at levels similar to those measured in human blood, caused an increase in mucin genes and mucous cell maturation in the lungs (Environmental Health Perspectives, National Institutes of Health).
Childhood lung diseases studied that may be impacted by BPA exposure
This study is of environmental health importance because increases in airway mucins are hallmarks of a number of childhood lung diseases that may be impacted by BPA exposure. Overly abundant secretion and storage of mucous can cause airway obstruction as found in a number of lung diseases including asthma and bronchitis.
CNPRC scientists Drs. Laura S. Van Winkle, Respiratory Diseases Unit, and Catherine A. VandeVoort, Reproductive Sciences and Regenerative Medicine Unit, along with co-authors Drs. Shannon R. Murphy and Miriam V. Boetticher (UC Davis Center for Health and the Environment), conducted this collaborative study to investigate the effects of BPA on fetal development.
Their data indicate that exposure to environmentally relevant levels of BPA during fetal lung development can alter expression of secretory genes (Muc5B, Clara cell secretory protein (CCSP)) and proteins (Muc5B mucins and CCSP) in the conducting airways. They also found that this increase is most pronounced in the bronchi (proximal conducting airways).
Pregnant monkeys and BPA exposure: Disruption of development of fetal ovaries
In companion studies conducted at the CNPRC, it has been shown that exposure of pregnant monkeys to BPA disrupts development of fetal ovaries, potentially causing birth defects and reproductive problems that would not emerge for a generation (Link); and that BPA also affects several developmental parameters of the mammary gland of rhesus monkeys, including some that are relevant to breast cancer risk in humans (Link).
The study of BPA in a primate model is critical because the rhesus monkey has estrogen levels as well as reproductive and developmental processes that are similar to humans. Dr. Van Winkle is a faculty member of the Department of Anatomy, Physiology and Cell Biology at the UC Davis School of Veterinary Medicine, and the UC Davis Center for Health and the Environment, as well as an Affiliate Scientist at the CNPRC. Dr. VandeVoort is a faculty member of the Department of Obstetrics and Gynecology, UC Davis School of Medicine, in addition to being a Core Scientist at the CNPRC. The National Institutes of Health funded this research.