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 Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

nachricht New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute

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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

Molecular switch detects metals in the environment

15.08.2018 | Materials Sciences

Seeing on the Quick: New Insights into Active Vision in the Brain

15.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>