Sunbathing Sharks

Sharks who spend too much time in the sun get a tan, researchers have discovered.

However, they do not appear to suffer from skin disease, raising hopes that shark skin could hold the key to beating skin cancer.

‘As far as I’m aware, sharks appear very robust to skin damage and disease,’ said Michael Sweet, a researcher in the School of Biology at Newcastle University’s Newcastle Institute for Research on Sustainability.

‘I don’t know what makes shark skin so special, but it definitely needs to be studied.

‘There have been a lot of attempts to induce melanomas in sharks to no affect.’

Researchers hope that if they can find the secret of how shark skin protects itself, it could be used to create a ‘shark lotion’ to protect human skin.

Another recent study, undertaken by the California State University Shark Lab, also looked at tanning in sharks.

Hammerhead shark pups held in a shallow clear seawater pond at the Hawaii Institute of Marine Biology darkened after several weeks, where UV levels are 600 times greater than those in their regular habitat of Kaneohe Bay.

An opaque filter was placed over the pectoral fins of untanned sharks to cut out UV light, to determine whether the darkening was due to solar radiation.

‘Areas of skin from under the opaque filter were untanned, whereas all other skin exposed to direct sunlight was considerably darker, resulting in distinct ‘tan lines’, the researchers said.

Our experiments demonstrated that the sharks were truly sun-tanning and that the response was, in fact, induced by the increase in solar radiation, particularly UV.

‘These sharks increased the melanin content in their skin by 14 percent over 21 days, and up to 28 percent over 215 days.’

The researchers said the only other animals known to suntan are mammals.

Attribution: Medical Daily, Mail Online

No More Sunburn

A paper wrist strap similar to the bands worn at festivals can help prevent over-exposure to the sun and reduce the risk of cancer.

The device lets people know when they have been exposed to a certain amount of UV (ultra-violet) radiation by changing color.

The monitor works by changing colour from yellow to pink as the strength of UV radiation increases.

The wristbands change color when the sun’s UV rays can start to cause damage.
It operates through an acid-release agent which picks up ultraviolet light and a dye which responds to pH levels in the indicator.

The agent is decomposed by sunlight, leading to the rapid change in color.

The bands will be tailored to different skin types to reflect the different tolerance levels that people have to the sun. For example, a band for someone with fair hair and light skin will change color quicker than a band for someone with dark hair and dark skin.

The technology will be commercialized by Swedish-based company Intellego Technologies, established by Swedish entrepreneur Claes Lindahl.

‘We are very excited about the UV dosimeter technology and we look forward to developing it further and commercializing it,’ said Lindahl. ‘There is a substantial need out in the market for a functional UV dosimeter and we look forward to continuing the process.’

Professor Andrew Mills and Dr Michael McFarlane are both responsible for the original invention and were previously with the University’s Department of Pure and Applied Chemistry. They will now be engaged as consultants to Intellego Technologies.

Mills said: ‘The bands will cost less than 20 cents each because they are disposable and need to be thrown away at the end of the day.

‘The sunburn monitor will make a significant contribution to public health as an affordable, fashionable device which enables people to enjoy the benefits of the sun while at the same time keeping them alert to the risks of over exposure.’ said Fiona Strang, Commercialization Manager with the University of Strathclyde, Glasgow, Research & Knowledge Exchange Services.

Attribution: Mail Online