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A new study from ��ñ�� researchers could change the way that medical professionals and scientists think about the long-term effects of skin immersion in water.

For a recently published paper, PhD student Niranjana Dhandapani and Associate Professor Guy German from the Thomas J. Watson College of Engineering and Applied Science’s Department of Biomedical Engineering tested samples of stratum corneum (the outer layer of human skin) from subjects 27 to 87 years old.

After 12 hours of immersion, the skin loses plasticity because of reduced ability to hold water. It also depletes both lipids and natural moisturizing factors, which can lead to long-term problems.

, a global hygiene and health firm based on Sweden, helped to fund the study and assisted in the research to better understand skin damage caused by diaper dermatitis, when infants or incontinent adults are not regularly changed.

“There have been issues with patients being left alone for extended periods of time without a fresh diaper on,” German said. “That can cause some pretty grisly medical outcomes, especially in people prone to disease.”

However, the findings have implications in a variety of different fields, including cryo-preservation, organ transport for transplantation, divers’ health, forensics and various foot-immersion syndromes.

In addition, German said, “this research has real-world implications for academics and technicians. If they’re doing experiments with tissue samples, irrespective of what the tissue is, they’re generally left refrigerated overnight or whenever the researcher can get the time to do the study.

“We receive skin tissue from surgery and from cadaveric tissue. In our line of work, when I’m looking at a study, I’ll read the methodology of how they did it to see if the tissue was received within 24 hours of surgery. Typically, however, when you have 100 different studies that can’t all be done on the same day, as the samples are taken, you have to realistically account for the pathology of the tissue and its journey before it was actually tested.”

The results of this study also tie in to German’s ongoing research about how our skin evolves as we get older, wrinkling and becoming more susceptible to fractures that can let in harmful bacteria.

“Some previous literature had said that the mechanical degradation of skin changes linearly with age — that it gets progressively worse,” he said. “Our findings seem to suggest that nothing really happens until the age of 70, and then you get this fast transition to more brittle skin more at risk of rupture and cracking .”

German’s funding for his NSF CAREER Award on the subject of skin aging also contributed funding to this study.

“One of the most revealing findings is that if you immerse skin tissue in water, the colder the water, the less damage that happens. That kind of makes sense to me,” he said, and added with a laugh: “I’ve threatened anyone who likes really long baths to go read this paper!”

German and Dhandapani’s study, was published in Extreme Mechanics Letters.