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
Bioinspired nanoscale drug delivery method developed by WSU, PNNL researchers
10.01.2019 | Washington State University
How herpesviruses shape the immune system
09.01.2019 | German Center for Infection Research
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.
Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...
Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
16.01.2019 | Life Sciences
16.01.2019 | Physics and Astronomy
16.01.2019 | Earth Sciences