(RxWiki News) Asthma rates of children in the US have risen steadily over the past 30 years, but specific causes for the increase have remained unclear.
In the past, pollution and tobacco smoke have been tied to the development of asthma. A new study now suggests that exposure to bisphenol A (BPA) during pregnancy may also play a role.
BPA is a common chemical used in some plastics and epoxy resins. It can be found in consumer products such as water bottles, CDs and medical devices, among many other products.
There have been some concerns about the safety of BPA. According to the National Institute of Environmental Health Sciences (NIEHS), people may be concerned about BPA for two main reasons. First, human exposure to BPA is widespread. Research by the Centers for Disease Control and Prevention (CDC) has found detectable levels of BPA in the vast majority of people 6 years of age and older.
The second possible cause for concern, says the NIEHS, may be animal studies showing effects in fetuses and newborns exposed to BPA.
Despite these concerns, the US Food and Drug Administration (FDA) says that the use of BPA in food containers and packaging is safe. People are exposed only to very small amounts of BPA through such food packaging.
For this new study, Adam J. Spanier, MD, and colleagues from the University of Maryland School of Medicine in Baltimore looked at whether contact with BPA was associated with decreased lung function, wheeze and asthma in infants and children.
This study, which was published Oct. 6 in JAMA Pediatrics, included 398 women from the Cincinnati, Ohio area who were enrolled during early pregnancy in the Health Outcomes and Measures of the Environment (HOME) study. The HOME study was designed to examine effects of environmental toxins on children’s health.
The researchers measured BPA levels in pregnant women twice, at 16 and 26 weeks of pregnancy. They also measured BPA levels in children each year after birth until the age of 5.
These researchers measured lung function, as shown by the amount of air a child could breathe out at ages 4 and 5, and reviewed parent-reported survey data in order to track if the children wheezed.
The investigators found that the higher a BPA level during a woman’s pregnancy was, the lower her child performed on lung function testing at age 4. They noted that a 10-fold increase in a mother's BPA level during pregnancy was linked to a 14.2 percent decrease in lung function of her 4-year-old child.
The researchers also found that the odds of a child wheezing were 58.4 percent greater with each 10-fold increase in mother's BPA levels.
Overall, an increase in a woman's prenatal urinary BPA level at 16 weeks was significantly linked with wheeze and decreased lung function in children, but it was not as significant at 26 weeks. BPA levels in the children made no difference to these results.
"If future studies confirm that prenatal BPA exposure may be a risk factor to impaired respiratory health, it may offer another avenue to prevent the development of asthma," the researchers wrote.
This study was supported by Flight Attendant Medical Research Foundation and the National Institute of Environmental Health Sciences. The authors disclosed no conflicts of interest.