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Pregnant women, fetuses exposed to antibacterial compounds face potential health risks

August 8, 2014

As the Food and Drug Administration (FDA) mulls over whether to rein in the use of common antibacterial compounds that are causing growing concern among environmental health experts, a team of scientists led by Arizona State University Biodesign Institute researchers are now reporting that many pregnant women and their fetuses are being exposed to these substances.

"We looked at the exposure of pregnant women and their fetuses to triclosan and triclocarban, two of the most commonly used germ-killers in soaps and other everyday products," says Benny Pycke, an ASU research scientist and co-author of the new study, published in the journal Environmental Science and Technology. silhouette of a pregnant woman Download Full Image

The work was presented at this week’s 248th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society.

"We found triclosan in all of the urine samples from the pregnant women that we screened. We also detected it in about half of the umbilical cord blood samples we took, which means it transfers to fetuses. Triclocarban was also found in many of the samples."

The problem with this, explains Pycke, is that there is a growing body of evidence showing that the compounds can lead to developmental and reproductive problems in animals, and potentially in humans. Also, some research suggests that the additives could contribute to antibiotic resistance, a growing public health problem.

Although the human body is efficient at flushing out triclosan and triclocarban, a person's exposure to them can potentially be constant.

"If you cut off the source of exposure, eventually triclosan and triclocarban would quickly be diluted out, but the truth is that we have universal use of these chemicals, and therefore also universal exposure," says Rolf Halden, lead investigator of the study and director of ASU’s Center for Environmental Security, a joint center supported by the Biodesign Institute and the Security and Defense Systems Initiative.

The compounds are used in more than 2,000 everyday products marketed as antimicrobial, including toothpastes, soaps, detergents, carpets, paints, school supplies and toys, the researchers say.

Showing what effect antimicrobials have on people is a challenge. But Halden and Pycke's colleague Laura Geer, of the State University of New York, found at least one interesting result.

Geer says the study yielded a link between women with higher levels of another ubiquitous antimicrobial, butyl paraben, which is commonly used in cosmetics, and shorter newborn lengths. The long-term consequences of this are not clear, but Geer adds that, if this finding is confirmed in larger studies, it could mean that widespread exposure to these compounds could cause a subtle but large-scale shift in birth sizes.

State policymakers, the FDA and industry have taken notice of the mounting evidence against triclosan. Minnesota became the first state to pass a ban on the antimicrobial's use in certain products, and it will take effect in January 2017. Some companies, such as Johnson & Johnson and Procter & Gamble, have announced that they are phasing out the compound from some products. At the federal level, the FDA and Environmental Protection Agency are reviewing the use and effects of the compounds.

Joe Caspermeyer

Managing editor, Biodesign Institute


New method of detecting bone loss could help predict disease progression

August 11, 2014

A team of researchers from Arizona State University and Mayo Clinic is showing how a staple of earth science research can be used in biomedical settings to predict the course of disease.

The researchers tested a new approach to detecting bone loss in cancer patients by using calcium isotope analysis to predict whether myeloma patients are at risk for developing bone lesions, a hallmark of the disease. X-ray of skull Download Full Image

They believe they have a promising technique that could be used to chart the progression of multiple myeloma, a lethal disease that eventually impacts a patient’s bones. The method could help tailor therapies to protect bone better and also act as a way to monitor for possible disease progression or recurrence.

“Multiple myeloma is a blood cancer that can cause painful and debilitating bone lesions,” said Gwyneth Gordon, an associate research scientist in ASU’s School of Earth and Space Exploration and co-lead author of the study. “We wanted to see if we could use isotope ratio analysis, a common technique in geochemistry, to detect the onset of disease progression.”

“At present, there is no good way to track changes in bone balance except retrospectively using X-ray methods,” said Ariel Anbar, a President’s Professor in ASU’s School of Earth and Space Exploration and the Department of Chemistry and Biochemistry. “By the time the X-rays show something, the damage has been done.”

“Right now, pain is usually the first indication that cancer is affecting the bones,” added Rafael Fonseca, chair of the Department of Medicine at the Mayo Clinic and a member of the research team. “If we could detect it earlier by an analysis of urine or blood in high-risk patients, it could significantly improve their care,” he added.

The research team – which includes Gordon, Melanie Channon and Anbar from ASU, as well as Jorge Monge (co-lead author), Qing Wu and Fonseca from Mayo Clinic – described the tests and their results in “Predicting multiple myeloma disease activity by analyzing natural calcium isotopic composition,” in an early online edition (July 9) of the Nature publication Leukemia.

The technique measures the naturally occurring calcium isotopes that the researchers believe can serve as an accurate, near-real-time detector of bone metabolism for multiple myeloma patients. Bone destruction in myeloma manifests itself in bone lesions, osteoporosis and fractures. The ASU-Mayo Clinic work builds on a previous NASA study by the ASU team. That research focused on healthy subjects participating in an experiment.

“This is the first demonstration that the technique has some ability to detect bone loss in patients with disease,” said Anbar, a biogeochemist at ASU.

With the method, bone loss is detected by carefully analyzing the isotopes of calcium that are naturally present in blood. Isotopes are atoms of an element that differ in their masses. Patients do not need to ingest any artificial tracers, and are not exposed to any radiation for the test. The only harm done with the new method, Anbar said, is a pinprick for a blood draw.

The technique makes use of a fact well-known to earth scientists but not normally used in biomedicine – different isotopes of a chemical element can react at slightly different rates. The earlier NASA study showed that when bones form, the lighter isotopes of calcium enter bone a little faster than the heavier isotopes. That difference, called isotope fractionation, is the key to the method.

In healthy, active humans, bone is in “balance,” meaning bone is forming at about the same rate as it dissolves (resorbs). But if bone loss is occurring, then the isotopic composition of blood becomes enriched in the lighter isotopes as bones resorb more quickly than they are formed.

The effect on calcium isotopes is very small, typically less than a 0.02 percent change in the isotope ratio. But even effects that small can be measured by using precise mass spectrometry methods available at ASU. With the new test, the ASU-Mayo Clinic researchers found that there was an association between how active the disease was and the change in the isotope ratios. In addition, the isotope ratios predicted disease activity better than, and independent from, standard clinical variables.

Anbar said that while the method has worked on a small set of patients, much still needs to be done to verify initial findings and improve the efficiency of analysis.

“If the method proves to be robust after more careful validation, it could provide earlier detection of bone involvement than presently possible, and also provide the possibility to monitor the effectiveness of drugs to combat bone loss.”

Associate Director, Media Relations & Strategic Communications