Issue Date: May 15, 2017 | Web Date: May 11, 2017
A breath test for dolphin health
The presence of certain molecules in the breath of dolphins exposed to the 2010 Deepwater Horizon oil spill correlates with signs of respiratory illness, a new study shows. The findings provide a set of biomarkers that researchers could use to assess the health of marine mammals using relatively noninvasive breath analysis (Environ. Sci. Technol. 2017, DOI: 10.1021/acs.est.6b06482).
As oil from the spill reached coastal regions along the Gulf of Mexico, researchers at the National Oceanic & Atmospheric Administration and the National Marine Mammal Foundation began monitoring the health of bottlenose dolphins in Barataria Bay, La., by taking blood samples and doing ultrasound tests. They also collaborated with Cristina E. Davis of the University of California, Davis, and her colleagues to perform breath analyses.
The UC Davis researchers had developed a Breathalyzer-type device that can capture organic compounds in dolphins’ breath. The researchers hold a squishy first-aid mask connected to a capped glass tube over the dolphin’s blowhole for about 10 breaths. Ice surrounding the tube freezes the compounds onto the glass. The scientists then use a plunger to scrape the trapped compounds into a vial for later mass spectrometric analysis and identification.
The researchers compared the Barataria Bay dolphins with two groups not affected by the spill: a wild population in Sarasota Bay, Fla., and a population managed and trained through the U.S. Navy Marine Mammal Program in San Diego.
The two healthy groups of dolphins had fairly similar profiles of breath metabolites, but dolphins exposed to the spill had quite different patterns. About two dozen compounds in the breath of Barataria Bay dolphins were linked with ultrasound diagnoses of lung consolidation, a possible sign of pneumonia. Some of these compounds are products of the breakdown of lung cells, including phosphatidylglycerol. The oil-affected dolphins’ breath also had bacterial metabolites that may be linked with bacterial pneumonia, and leukotriene E3, a marker of asthmatic inflammation.
“It’s a fantastic, innovative study,” says Jonathan Beauchamp, an expert in breath analysis at the Fraunhofer Institute for Process Engineering & Packaging. “It’s quite impressive to have such good separation” of the metabolites in the different populations, he says. He adds that the method could complement current tools to assess the effects of disasters on marine mammals.
- Chemical & Engineering News
- ISSN 0009-2347
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