NPSFriday 28 September 2012, 2:25PM
Media release from NPS
Writing in the latest edition of Australian Prescriber, Associate
Professor Jane Hanrahan from the Faculty of Pharmacy, University of
Sydney writes that UVB is the cause of sunburn, but UVA can be more
damaging to the skin. It is therefore best to use broad spectrum
sunscreens that block both wavebands.
Sunscreens were originally developed to prevent sunburn caused by
ultraviolet B (UVB) radiation, but we now know that it is just as
important for them to block ultraviolet A (UVA) radiation, which is
responsible for some types of skin cancers as well as premature
ageing of the skin.
"The incidence of skin cancers, particularly melanomas, has
continued to increase in Australia despite 30 years of the 'Slip,
Slop, Slap' sun protection campaign. This is partly due to the fact
that the sun protection factor rating, or SPF, in sunscreens is
biased towards protection from UVB rays and prevention of sunburn,
but does not measure how effective a sunscreen is at blocking UVA,"
Associate Professor Hanrahan writes.
"The newer broad spectrum sunscreens that have been available since
the 1990s and protect against UVA and UVB wavebands, provide hope
of a decrease in the incidence of some skin cancers in the
future."
New Australian and New Zealand standards now permit sunscreens to
have an SPF rating of up to 50+. Previously, only SPF 30+ was
available in Australia.
There have been concerns in the past that newer sunscreens, which
offer cosmetic benefits in terms of looking more transparent when
applied, may in fact be harmful because of the absorption of
nanoparticles into the skin, which could have toxic effects on the
body.
The Therapeutic Good Administration, however, found that
nanoparticles in sunscreens do not penetrate deep enough into
normal intact skin to be toxic.
"Despite possible concerns about the long-term safety of
sunscreens, the benefits of using sunscreen outweigh the possible
harms," Associate Professor Hanrahan concludes. "However sunscreens
should only be one part of a sun protection strategy. Staying out
of the sun where possible and covering up exposed parts of the body
are still a priority."
Other articles in this issue look at the rise of herpes zoster and
an update on antivenom.
To read the full article and others visit www.australianprescriber.com