Photo by Shawn Jones
People have always been told to wear sunscreen. It is said to protect from sunburns, wrinkles and even skin cancer. Doctors recommend sunscreen to their patients, moms lather their children before any outdoor activities and students on summer break practically live in a layer of sunscreen from March to September.
But what is actually in sunscreen? Have you ever thought to look at the ingredients while you are checking out its SPF?
This summer, Chemistry Professor Jane Ganske and her student research team studied one of the main ingredients in popular sunscreen brands, a substance that is potentially more harmful to health than helpful.
“Even though cosmetic companies coat their titanium dioxide with a coating that’s supposed to suppress this photocatalytic response, it’s not 100 percent effective,” Ganske said.
The contentious ingredient, known as titanium dioxide, is controversial due to its potentially harmful side effects, such as the increased risk of aging and cancer, when it is exposed to sunlight. Senior Marissa Kaak and junior Maddy Byrd chose to spend their summer in the lab with Ganske, studying how titanium dioxide reacts with certain elements of human skin when exposed to sunlight.
In what is known as the “photocatalytic response,” or an increased activity rate when exposed to sunlight, titanium dioxide generates free electrons, which can react with other particles to create free radicals.
Free radicals are unstable molecules that fragment other particles (scientifically speaking, they attempt to take the unpaired electrons of stable molecules so they themselves can become stable molecules). This creates a cascading effect of stimulating more and more free radicals, which are believed to be a significant factor in aging and cancer risk.
This means that titanium dioxide, when exposed to the sun, reacts by creating small, hazardous particles that can bond and form even more hazardous particles, known to cause aging and sometimes cancer. Yet this ingredient is still used in sunscreen and even some cosmetic products.
Kaak examined the mechanism by which titanium dioxide breaks down and the resulting fragmented particles it creates. Byrd studied each specific fragmented particle and determined the strength of resulting free radical concentration. Their research has not yet been published, but their findings so far leave room for one to wonder: Are all sunscreens equal in protecting our skin? Or do some do more damage than they protect?
Many cosmetic companies believe that by coating titanium dioxide with a protective coating and decreasing its size to that of a nanoparticle, that its photocatalytic response rate slows and these risks are significantly decreased.
However, Ganske’s research suggests that this coating may not be as effective as some cosmetic companies advertise or would have the public believe, and that by decreasing its size to a nanoparticle, the risks of aging and cancer may be increased.
“Some chemists have actually shown that different crystal structures of titanium dioxide have different photocatalytic activities and that one structure is less photoactive than another, yet it still works as a sunscreen,” Ganske said.
There are ways to make titanium dioxide safer, but much research still needs to be done.
Beyond its effects on constituents of human skin, Ganske said her concerns extended past the mere human health effects and into an environmental concern.
“[When] titanium dioxide gets into waste water, it’s capable of interacting with bacteria in a negative way,” she said, concerned that the environmental impact of titanium dioxide could be far reaching, and deeply devastating.
Though their research is not yet complete, the study suggests that titanium dioxide may increase the output of free radicals, therefore potentially harming the human body in the long term.
Follow Connor Shewmake on Twitter: @connorshewmake