Safety warnings for nano sunscreens aren't justified, researchers argue.
Credit: iStockphoto
Sunscreens are an important public health issue for Australians, and deserve balanced reporting. This involves weighing up the known risk of skin damage from excessive ultraviolet (UV) light exposure with a perceived risk of using nano sunscreens.
Sun damage occurs from penetration into the skin by UVA and UVB radiation. Both UVA and UVB can damage the genetic material inside a cell – an effect called genotoxicity, which can lead to tumour formation.
But UVA penetrates much deeper into the skin than UVB and has the main genotoxic effect on the cells in the basal epidermal layer of skin, where most skin cancers originate. So sunscreens that are effective blockers across a broad UV spectrum provide the best skin protection.
Misinformation in the public arena may stop parents and teachers from using the broadest UV protective sunscreens on children – especially those metal oxide-containing sunscreens that provide very good protection against harmful UVA exposure.
In May 2011, the Victorian State branch of the Australian Education Union voted to urge schools to use nano-free sunscreens as part of their Sunsmart programs, until research conclusively proves that nano-products are not toxic.
Schoolchildren need to be using the most protective sunscreens available, as severe sunburn in children is a major risk factor for melanoma incidence in adults. The most effective broad spectrum UV blockers are the physical blockers, such as the metal oxides zinc oxide and titanium dioxide. These both absorb and reflect UV, don’t break down under UV exposure and are longer-acting than organic UV blockers.
Concerns about nano-sunscreens have been mounting since a report three years ago by BlueScope Steel researchers Philip Barker and Amos Branch stating metal oxide nanoparticles in some sunscreens had photocatalytic activity – an accelerated photoreaction - capable of bleaching painted surfaces of coated steel. This draws a long bow, as both the nature of the target site affected and the UV-sunscreen co-exposure circumstances are very different.
Several studies have since shown that there is negligible penetration of metal oxide nanoparticles past the outer dead cell layer (in the stratum corneum) of healthy or damaged skin. The skin is also constantly shedding its outer layer of dead cells.
Nano
Regarding the labeling of nano sunscreens, can not businesses (for-profit) over the protection of consumers. If the term nano can not be used to warn of hazards in products, then companies can not Fabries anything containing nano until the polls actually show that it is not toxic.
Here in Brazil, unfortunately, also has high rates of skin cancer, but the dangers of nanoparticles in sunscreens can not be worse than those made by the sun. We Hitori at a time that we engage the people to decide on the risks we want. Here are the paradigm of human risk.
I would be happy with a
I would be happy with a requirement of informing consumers that there is nano in a product in the interest of allowing people information to make their own decisions but not as a warning label. Personally I would only buy stuff with nano in it b/c it's cool and I have a mental tic to not use sunscreen normally, doubting its usefulness and the manliness of not facing the sun unarmed so I would be much likelier to use it for the techno sugar rush.
However that probably won't affect me much in Canada anyways.
Nanoparticles cause brain injury in fish
Maybe after reading this, the labelling dilemma will be solved. The public should be able to choose what they apply to their skin [or ingest]and its difficult to ascertain if a substance is causing a problem if you don't know that you're exposed to it.
Nanoparticles cause brain injury in fish
(Nanowerk News) Scientists at the University of Plymouth have shown, for the first time in an animal, that nanoparticles have a detrimental effect on the brain and other parts of the central nervous system.
They subjected rainbow trout to titanium oxide nanoparticles which are widely used as a whitening agent in many products including paints, some personal care products, and with applications being considered for the food industry. They found that the particles caused vacuoles (holes) to form in parts of the brain and for nerve cells in the brain to die. Although some effects of nanoparticles have been shown previously in cell cultures and other in vitro systems this is the first time it has been confirmed in a live vertebrate.
The results will be presented at the "6th International meeting on the Environmental Effects on Nanoparticles and Nanomaterials" (21st – 23rd September) at the Royal Society in London.
"It is not certain at this stage of the research whether these effects are caused by the nanoparticles entering the brain or whether it is a secondary effect of nanoparticle chemistry or reactivity", says Professor Richard Handy, lead scientist.
The results of Professor Handy's work and that of other researchers investigating the biological effects of nanoparticles may influence policy regulations on the environmental protection and human safety of nanomaterials.
"It is worrying that the effects on the fish brain caused by these nanoparticles have some parallels with other substances like mercury poisoning, and one concern is that the materials may bioaccumulate and present a progressive or persistent hazard to wildlife and to humans", says Professor Handy.
Source: Society for Experimental Biology