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
Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel
Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy