Everyone knows that too much time in the sun isn't good for your skin. It massively increases the chances of developing skin cancer, and as new research shows and suggests, a compound found in most sunscreens may alos increase the chances of getting melanoma.

The research, carried out at the Missouri University of Science and Technology looked into what happens to the compounds in sunscreen when they're exposed to light. they found that zinc oxide, a staple ingredient in the sunscreen undergoes a chemical reaction when its illuminated by bright light and may release unstable molecules known as free radicals.

Free radicals readily bond with other molecules but in the process can damage cells or the DNA containined within those cells, which will then in turn increase the risk of skin cancer. The tests were carried out in the lab using lung cells covered in zinc oxide solution, suggesting that UV light causes the reaction to take place most strongly.

The research, which is to be published in the Journal of Toxicology and Applied Pharmacology, suggests that the harmful effects of the free radicals increases the longer zinc oxide is exposed to sunlight. 3 hours of UV exposure caused half of the lung cells covered in zinc oxide solution died. And after 12 hours, that increased to 90 percent.

Should people be concerned? This is still a small study, and it was conducted with lung cells rather than skin cells, and still there's not enough data to decide if on balance that sun screen can cause more harm than good. Dr Yinfa Ma one of the researchers says:
Still, don't stay out in the sun for too long. It really isn't good for you. [PhysOrg]