New Sunscreen "Sticks" to the Skin
The active ingredients are encapsulated in nanoparticles, which prevent the chemicals from seeping into the body
Under intense summer rays sunscreen can help protect against a wicked burn, but some of the common active ingredients in these sprays and lotions can also seep through the skin and enter the bloodstream. Although it is unclear whether this poses any risks, Yale University dermatologist Michael Girardi thinks it is worthwhile to develop alternatives. In collaboration with the university's bioengineering department, he has developed a sunscreen formulation designed to keep chemicals on the skin's surface.
The sunscreen chemicals that absorb the sun's dangerous ultraviolet radiation are typically organic molecules (as opposed to the metal oxides that block the sun's rays in sunblock). There is no evidence that these absorbing molecules can directly harm humans. A small body of research that includes animal and cell-culture studies, however, shows that some of them can bind to hormone receptors. The results may suggest a potential to disrupt the body's endocrine system, the traffic of hormones that regulates reproduction and other functions.