Intensive Care Linked to BPA Exposure in Newborns

Highest levels of pollutant occur in sickest babies, study finds

byJanet Raloff

Web edition: February 22, 2013

Hospitals rush newborns into a neonatal intensive care unit when those babies are struggling to survive. Although NICUs offer tender and vigilant care, many of the devices they rely on can expose their tiny patients to a relatively large dose of a hormone-mimicking pollutant, bisphenol A.

Newborns in intensive care excrete BPA, on average, at levels of around 17.8 micrograms per liter — well above the 0.45 µg/l typical of healthy infants, researchers report in the March Pediatrics. One of the most reliable indicators of BPA exposure was the level of care that a baby received, reflected by the number of devices used to deliver that care, notes nurse and exposure-science researcher Susan Duty of Simmons College in Boston. Breathing tubes, intravenous drug delivery lines and enclosed incubators are plastic, and several types of plastic can contain BPA.

Although researchers have not figured out what doses of BPA cause toxicity in people, several studies have linked elevated prenatal exposures to later behavioral problems (SN Online: 7/16/12) and moodiness (SN: 11/7/09, p. 12) in young children. Animal studies have also linked BPA exposure during development to feminization in males and risks of later hypertension and diabetes.

Duty’s team studied 55 infants, each of whom spent at least three days in a NICU in the Boston area, and most of whom had been born prematurely or were for other reasons very small. The researchers measured BPA in the breast milk and formula that these tiny babies consumed. Both nutritional sources had small, comparable amounts of BPA.

Regular urine samples then revealed how much BPA the babies had encountered.

The urine of newborns who had received treatment with four or more NICU devices contained 36.6 µg/l BPA on average. That level was almost three times as much as babies treated with three or fewer devices. “I was surprised,” Duty says, “especially because this particular [NICU] had taken considerable care to purchase products that were BPA-free whenever possible.”

Roughly one-fifth of the babies had been treated with at least four medical devices. Contrary to her expectations, Duty found that respiratory devices, not IV tubing, proved to have the strongest link with elevated BPA levels.

Another surprise was that prematurity accounted for 30 percent of the variability in urinary BPA, says Laura Vandenberg, a developmental biologist at Tufts University in Medford, Mass., who was not involved in the study.  

One possible explanation for prematurity’s link to BPA levels emerged at the American Association for the Advancement of Science annual meeting in Boston. On February 17, researchers with the Food and Drug Administration’s National Center for Toxicological Research in Jefferson, Ark. reported rodent and monkey experiments showing that very young animals broke down BPA very slowly (SN: 3/9/13, p. 9).

If the animal data hold true for humans, Vandenberg says, immature babies may get a more potent punch from BPA simply because their bodies are relatively inefficient at breaking down the compound.

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Intensive care linked to BPA exposure in newborns
Highest levels of pollutant occur in sickest babies, study finds

* * * Diabetes & Obesity? * * *

In the 1967 film classic The Graduate, a businessman corners Benjamin Braddock at a cocktail party and gives him a bit of career advice. "Just one word…plastics."

Although Benjamin didn't heed that recommendation, plenty of other young graduates did. Today, the planet is awash in products spawned by the plastics industry. Residues of plastics have become ubiquitous in the environment—and in our bodies.

A federal government study now reports that bisphenol A (BPA)—the building block of one of the most widely used plastics—laces the bodies of the vast majority of U.S. residents young and old.

Manufacturers link BPA molecules into long chains, called polymers, to make polycarbonate plastics. All of those clear, brittle plastics used in baby bottles, food ware, and small kitchen appliances (like food-processor bowls) are made from polycarbonates. BPA-based resins also line the interiors of most food, beer, and soft-drink cans. With use and heating, polycarbonates can break down, leaching BPA into the materials they contact. Such as foods.

And that could be bad if what happens in laboratory animals also happens in people, because studies in rodents show that BPA can trigger a host of harmful changes, from reproductive havoc to impaired blood-sugar control and obesity (SN: 9/29/07, p. 202). ?p?For the new study, scientists analyzed urine from some 2,500 people who had been recruited between 2003 and 2004 for the National Health and Nutrition Examination Survey (NHANES). Roughly 92 percent of the individuals hosted measurable amounts of BPA, according to a report in the January Environmental Health Perspectives. It's the first study to measure the pollutant in a representative cross-section of the U.S. population.

Typically, only small traces of BPA turned up, concentrations of a few parts per billion in urine, note chemist Antonia M. Calafat and her colleagues at the Centers for Disease Control and Prevention. However, with hormone-mimicking agents like BPA, even tiny exposures can have notable impacts.

Overall, concentrations measured by Calafat's team were substantially higher than those that have triggered disease, birth defects, and more in exposed animals, notes Frederick S. vom Saal, a University of Missouri-Columbia biologist who has been probing the toxicology of BPA for more than 15 years.

The BPA industry describes things differently. Although Calafat's team reported urine concentrations of BPA, in fact they assayed a breakdown product—the compound by which BPA is excreted, notes Steven G. Hentges of the American Chemistry Council's Polycarbonate/BPA Global Group. As such, he argues, "this does not mean that BPA itself is present in the body or in urine."

On the other hand, few people have direct exposure to the breakdown product.

Hentges' group estimates that the daily BPA intake needed to create urine concentrations reported by the CDC scientists should be in the neighborhood of 50 nanograms per kilogram of bodyweight—or one millionth of an amount at which "no adverse effects" were measured in multi-generation animal studies. In other words, Hentges says, this suggests "a very large margin of safety."

The entire artical can be read in Science News Magazine if you are a subscriber.

*-*-*-*-*-*-*-*-    Update  12-10-10    *-*-*-*-*-*-*-*-

Skin is no barrier to BPA, study shows

Finding suggests handling store receipts could be significant source of internal exposure

By: Janet Raloff

December 4th, 2010; Vol.178 #12, (p. 10)

Bisphenol A readily passes through skin, French scientists report. Best known as an estrogen-mimicking constituent of some plastics and resins, BPA is also found in a large share of cash register receipt paper in the United States and Europe, a trio of studies recently indicated. One of the three also showed that the powdery coating easily rubs off onto the hands.

For entire article go to Science News magazine.

*-*-*-*-*-*-*-*-    Update  02-01-13    *-*-*-*-*-*-*-*-

Intensive care linked to BPA exposure in newborns

Highest levels of pollutant occur in sickest babies, study finds