The effects of lifelong daily sunscreen use have not been evaluated. The randomised controlled trial (in Nambour, Queensland) on which this HANDI intervention is based followed daily sunscreen use for almost 15 years.
There has been some concern about whether the titanium dioxide and zinc oxide nanoparticles used in some sunscreens can be absorbed into the skin. The Cancer Council advises that nanotechnology does not pose a risk to patients based on the current available evidence.
Research suggests that sunscreen nanoparticles do not penetrate into the deeper skin layers containing the viable skin cells or reach the bloodstream through the skin. Research is ongoing into the potential side effects of this technology.
(Note: The ‘microfine’ or ‘micronised’ particles found in some sunscreens are larger than nanoparticles.)