Wednesday, March 18, 2009

There's WHAT In My Sunscreen?!!


Photo courtesy: Discovery Channel Website

One day in the not-to-distant future, you may be on the beach when someone offers to pass you the hippo sweat which you generously slather all over your sun-worshipping body. The times they may be a’changing; but, hippo sweat?

Most people don’t realize that hippos actually have incredibly sensitive skin. Intrinsic to their survival is a red-coloured, glandular secretion known as “hippo sweat”,

Hippo sweat contains microscopic structures that scatter light thereby protecting the mammals (and their sensitive skin) from painful burns says a new study. Scientists are hoping they can put this knowledge to work in an advanced sunscreen/sunblock that may help protect humans from the harmful effects of the sun’s rays including skin cancers.

"It would be nice to also try and replicate the antiseptic and insect-repellent characteristics of the sweat, to obtain a four-in-one product: sunscreen, sunblock, antiseptic, insect repellent," co-author Christopher Viney told Discovery News.

"Just so long as the stuff doesn't smell like hippo," added Viney, a professor in the School of Engineering at the University of California, Merced.

In one experiment with hippo sweat, Christopher Viney, along with colleagues Emily Reed, Lisa Klumb and Maxwell Koobatian had keepers at Fresno’s Chaffee Zoo remove some of the sweat from an enclosure where the hippos had rested. The sweat was placed in sealed plastic containers where, even after several months of storage, no signs of yeast, bacteria or fungal contamination were found.

Microscopic analysis of the sweat revealed it contained two types of liquid crystalline structures: banded and non-banded. The banded structures are “characterized by concentric dark rings” when viewed under certain magnifications, Viney explains.

"The rings are the result of a structural periodicity that occurs on a scale comparable to the wavelengths of visible light," he said. "This means that the sweat is an effective scatterer of light, so that it combines both sun-blocking and sun-screening properties."

The non-banded structures "enhance the ability of the sweat to spread over the surface of the animal, by reducing the viscosity of the sweat."

Research on the molecules in the red and orange pigments contained in the sweat show that these pigments are capable of absorbing ultraviolet light. However, the pigments can cause the secretions to be of such a vivid red colour many onlookers have thought the hippo was bleeding when he/she was only sweating.

According to David Kaplan, chair of the Department of Biomedical Engineering at Tufts University School of Engineering has this to say about the study’s authors: they "have a terrific handle on novel functional materials that come out of nature." He added that Viney is leading world expert in the field.

Kaplan's own department often turns to natural materials in their work because "nature has provided us with substances that have emerged after eons of evolution. There is so much invaluable data that has yet to be mined."

Viney agrees. "As a student said to me several years ago, nature is full of solutions to our technical problems," he said. "We just have to figure out how to look in the right place, and ask the right questions."

I think I would reword that slightly to: “We just have to figure out how to look in the right place (if it still exists), and ask the right questions (if they’re still pertinent).”

Readers: would you wear a sunscreen/sunblock made from hippo sweat?

1 comment:

kathi said...

I would, as long as it didn't smell like Hippo, as Vinney said. I HAVE to use sunscreen and insect repellent almost daily except when cold so something like this would be great.