Washington D.C. , Nov 25 : Applying sunscreen on your body may be good for your skin but its nanoparticles can also affect your skin adversely.
A new study led by the researchers at the University of Queensland and University of South Australia provides the first direct evidence that zinc oxide nanoparticles used in sunscreen neither penetrate the skin nor cause cellular toxicity after repeated applications.
The research, published in the Journal of Investigative Dermatology, refutes widespread claims and a growing belief among consumers about the safety of nanoparticulate-based sunscreens.
The researchers said that the myth about sunscreen toxicity took hold after previous animal studies found much higher skin absorption of zinc-containing sunscreens than in human studies.
“There were concerns that these zinc oxide nanoparticles could be absorbed into the epidermis, with toxic consequences, including DNA damage,” said Michael Roberts, lead researcher.
The toxicity link was picked up by consumers, sparking fears that people could reduce their sunscreen use, echoed by a Cancer Council 2017 National Sun Protection Survey showing a drop in the number of people who believed it was safe to use sunscreens every day.
Roberts and his co-researchers studied the safety of repeated applications of zinc oxide nanoparticles applied to five volunteers aged 20-30 years. Volunteers applied the ZnO nanoparticles every hour for six hours on five consecutive days.
Using superior imaging methods, researchers established that the nanoparticles remained within the superficial layers of the skin and did not cause any cellular damage.
“We hope that these findings help improve consumer confidence in these products and in turn lead to better sun protection. The terrible consequences of skin cancer and skin damage caused by prolonged sun exposure are much greater than any toxicity posed by approved sunscreens,” Roberts concluded.