In the worlds sunny climates like Australia, melanoma and non-melanoma skin cancers are often the most common types of cancers found. The application of sunscreen has been found to be one of the best ways to prevent basal cell carcinomas and melanomas. Most conventional sunscreens were of two varieties, containing either oxybenzone and octinoxate or titanium dioxide and zinc oxide. Conventional chemical sunscreens are less effective than mineral sunscreens, but go on clear and adhere longer by soaking into the skin. Bulk mineral sunscreens with titanium or zinc leave a white film, but are biologically benign when in the micron range or larger. In both cases, there are serious benefits and drawbacks for either type.
For these reasons, the role of sunscreen is an important one. Research and development in the sunscreen market focuses on keeping sunscreen on longer, increasing the consumer friendliness of sunscreen products and increasing theprotection of sunscreens against exposure to skn-wrinkling UV-A and cancer-causing UV-B rays better. As people stay exposed longer and are more fashion conscious, sunscreens are expected to be effective while not interfering with a person's look.
Zinc oxide and titanium dioxide nanoparticles seem to be the golden solution, offering all of the positive attributes that consumers and manufacturers are looking for in sun protection, without hormone altering chemicals such as oxybenzone or octinoxate. When bulk titanium and zinc minerals are reduced to the nanoparticle size, they are much more effective at blocking UV rays and their application is much less noticeable. This reduction in scale does create unintended consequences. Titanium dioxide at the nanoscale is a photocatalyst, creating harmful free-radicals and damaging DNA when it reacts with sunlight. To overcome this, researchers have found that coating the particles with grapeseed oil and organic polymers prevents the photocatalytic effect from causing DNA damage to the body.
Because of this breakthrough in sunscreen engineering, nanoparticle mineral additives in sunscreen have become nearly ubiquitious in sunscreen formulations. A lack of regulation also makes it near impossible to determine what specific types and sizes of particles are in sunscreens. Most sunscreens do not label if they put nanoparticles into their products, leta alon if those particles are polymerized, leaving many consumers still just as lost as they were when evaluating conventional sunscreens.
There may be some risk of these compounds entering the bloodstream through absorbtion or cuts,skin abrasions, inhalation and swallowing. Titanium dioxide has also been proven damaging to cells and DNA due to its photocatalytic effect. This effect also raises concerns over the environmental fate and transport of sunscreen as it is washed off consumers and enters the local water source. These health risks exists for all sunscreen products, but may be countered by the known risk of cancer and the benefits of UV protection.