Nanopartikel in der Sonnencreme - Gar nicht so schlecht!
Die Environmental Working Group (EWG), eine Nichtregierungs-Organisation aus den USA, hat die 2009er-Version ihres Suncreen-Reports veröffentlicht. Die EWG erwartete zwar, sich gegen den Einsatz von mikro- und nanoskaligem Zinkoxid und Titandioxid aussprechen zu müssen, doch nach Monaten der Untersuchung und Analyse von fast 400 peer-reviewed Studien empfehlen sie nun einige Sonnenschutzprodukte, welche Nanopartikel enthalten können.
EWG's study found that consumers who use sunscreens without zinc and titanium are likely exposed to "... more UV radiation and greater numbers of hazardous ingredients than consumers relying on zinc and titanium products for sun protection. We found that consumers using sunscreens without zinc and titanium would be exposed to an average of 20% more UVA radiation — with increased risks for UVA-induced skin damage, premature aging, wrinkling, and UV-induced immune system damage — than consumers using zinc- and titanium-based products. On the contrary, a 2007 Consumer Reports testing found that consumers could be protected from UV radiation using products free of nano-scale ingredients like zinc and titanium.
EWG took a comprehensive approach in testing over 2000 suncreen products. They looked not only at whether or not products provide broad-spectrum UV protection, but also at which sunscreens break down in the sun, and at the full range of potentially hazardous sunscreen ingredients that can absorb through the skin and into the body to pose other risks.
"Sunscreens without zinc or titanium contain an average of 4 times as many high hazard ingredients known or strongly suspected to cause cancer or birth defects, to disrupt human reproduction or damage the growing brain of a child."
A review of 16 studies on skin absorption of zinc oxide and titanium dioxide nanoparticles revealed that nearly all studies showed no absorption of small-scale zinc and titanium sunscreen ingredients through healthy skin, while other studies did show that the common sunscreens octinoxate and oxybenzone, do absorb into skin, often in large quantities, with potentially harmful results, including allergic reactions, and increased risk of breast cancer.
EWG conducted the sunscreen study because comprehensive sunscreen safety standards have not yet been set in the US. FDA has been drafting such standards for 31 years, and the agency has not yet evaluated sunscreen chemicals that are widely available. For nano-scale ingredients EWG also called for full labeling so consumers can make informed choices.
On balance, EWG researchers found that zinc and titanium-based formulations are among the safest, most effective sunscreens on the market based on available evidence. However, in some sort of precautionary approach, they only recommend using nano suncreens if the nanomaterial brings a clear advantage: "If it's not protecting your health, don't use it."
Adapted from: Environmental Working Group (EWG) Nanotechnology & Sunscreens