Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Less Sun better than using sunscreen

03.05.2007
With the northern hemisphere summer approaching, many people will be taking advantage of the hot weather to sunbathe and relax in the hot weather in parks and on beaches.

But avoiding direct sunlight and wearing clothes which stop harmful UV rays from reaching the skin, rather than sunscreen, are the best ways of avoiding skin cancer and the aging effects of the sun. This timely advice forms part of a Review published early Online and in an upcoming edition of the Lancet.

Dr Stephan Lautenschlager, Outpatient Clinic of Dermatology, Triemli Hospital, Zurich, Switzerland, and colleagues carried out the comprehensive review on sun protection strategies around the world.

The authors say: “Wearing sun protective clothes and a hat and reducing sun exposure to a minimum – should be preferred to sunscreens. Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons, for example healthiness of a tan, relaxation in the sun.”

They add: “Nevertheless, sunscreens should not be abused in an attempt to increase time in the sun to a maximum.”

The Review highlights the characteristics of clothing that can make all the difference in terms of sun protection factor (SPF). Tightly woven, thick garments made of denim, wool or polyester offer the best protection, while cotton, linen and acetate are much less effective. Lax, dry material, and clothes that have shrunk after washing (thereby making them denser) are better at stopping harmful UV rays reaching the skin, while wet or stretched materials, and those that have been bleached, are not so good.

Sunscreen of varying SPFs is applied, depending on skin type and personal preference - but what does SPF actually mean? SPF is defined as the minimum sun radiation dose (mainly UVB) required to produce sunburn after application of 2mg per square centimetre, divided by the dose of sunlight to produce the same effect on unprotected skin. This translates to a protection factor of 50% for SPF2, 87.5% for SPF8, 93.6% for SPF16, and 96.9% for SPF32.

Sunscreens fall into two categories – inorganic and organic. Inorganic sunscreens act by scattering UV light using zinc or titanium oxides but are generally less cosmetically favourable due to their opaque nature. However they are generally very well tolerated by the skin and produce few allergic effects, thus are recommended for children.

Organic sunscreens actually absorb the UV rays, and as the name suggests consist of a range of complex organic molecules which blend together to give photoprotective qualities.

While many studies have shown that sunscreen protects against acute UV skin damage and non-melanoma skin cancer, whether sunscreen stops melanoma developing has not been conclusively proven.

The authors conclude: “The population has to be advised how to best make use of suncreens. The application of a liberal quantity of sunscreen, is by far the most important factor for effectiveness of the sunscreen, followed by the uniformity of application and the specific absorption spectrum of the agent used.

“Application of organic sunscreens should be done 15-30 minutes before going out into the sun. Waterproof or water-resistant sunscreens should be used to diminish the need for reapplication after swimming followed by towelling, friction with clothing or sand, and sweating.”

Tony Kirby | alfa
Further information:
http://www.lancet.com

More articles from Health and Medicine:

nachricht Second cause of hidden hearing loss identified
20.02.2017 | Michigan Medicine - University of Michigan

nachricht Prospect for more effective treatment of nerve pain
20.02.2017 | Universität Zürich

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Positrons as a new tool for lithium ion battery research: Holes in the electrode

22.02.2017 | Power and Electrical Engineering

New insights into the information processing of motor neurons

22.02.2017 | Life Sciences

Healthy Hiking in Smart Socks

22.02.2017 | Innovative Products

VideoLinks
B2B-VideoLinks
More VideoLinks >>>