A study out of Binghampton University in New York has found that no UV range (UVA or UVB) is more harmful than the other; the damage actually appears to scale with the amount of energy that the skin absorbs. Even more significant, UV weakens the bonds between cells in the stratum corneum by affecting corneodesmosomes, which help the cells adhere together. Researchers used samples of female breast skin—typically only exposed to low levels of sunlight—and subjected them to various wavelengths of UV radiation. “What we noticed when we applied more and more UV radiation is that the dispersion of these corneodesmosomes was increasing,” says Zachary W. Lipsky, a biomedical engineering PhD candidate at Binghamton. “With more irradiation, they essentially look exploded, moving away from their position. We conclude that because of the disruption of these corneodesmosomes, it damages the skin’s structural integrity.”
The researchers are further investigating how UV radiation affects deeper layers of the skin. Lipsky says the most important takeaway for now is that skin protection is crucial no matter the season. “We’re trying to push the message to use sunscreen not just for preventing skin cancer, but also to keep the integrity of your skin so you don’t get infections or other problems,” he notes.