Slip slop slap. It's an all too common slogan preceding some fun in the sun but recently this has all but changed. With the advent of Nano particles, science's latest achievement, product manufacturers keen to be seen at the leading edge have jumped on board. In this article I will raise some of the possible issues?
Nano technology's latest product is sunscreen. What's the problem you ask? In an nutshell, it's all in just how small these ingredient particles are. In the nano's case think invisible to the human eye. Particles so small that the size of our hair is 800 x larger. On first thought, this sounds like a great idea, who would't like a sunscreen that doesn't leave visible streaks?
The trouble is, their main feature is actually their worst aspect.... their size. These particles are so incredibly small that they are literally dwarfed by the cells of our bodies. They are so tiny that they can indeed fit through the cell membranes in our skin and other organs. This makes their entry into our cells and organs beyond the control mechanisms of the cells which typically use receptor sites to control access and function.
Bit like not being able to say enough to food or drink. Think of it like thieves that are avle to enter your home through the gaps inder windows, vents, doors etc.
Right up to the artificial development and use of nano particles our cells and organs were able to identify, choose and control what to absorb and when. Like our house doors they are useful in protecting our possessions and us from intruders and anything outside of this self control system, as in the case of environmental particles usually results in diseases such as the respiratory deseases associated with carbon derived particles, these Nano particles, in the order of 1-100nm, they just slip through our built in controls and defences. It doesn't help that our skin, the very organ being slip-slop-slapped, is the largest transpiring organ we have, it's our second lung and the jury is very much out as to the eventual results.
A big part of the problem is that these particles are seen as at a certain place, in the case of sunscreen on our arms and faces but what if they move as in the case of you grabbing a piece of fruit and eating it (after applying the sunscreen). No one has studied the effects of uncontrolled absorption of .... for arguments case, titanium dioxide or for that matter zinc oxide - typical sunscreen active ingredients on the skin let alone in the mouth, throat, stomach and the intestines. Keep in mind, nano particles may also be in your moisturiser, makeup or cleanser. These are just one of the nano sized substances being used. Further proposals to fortify human foods with "Neutracuticles" to modify flavours and change nutritional properties are in consideration for the near future. The problem once again being - the dosage is again outside the control of our body's cells and their feedback mechanisms. You might like to think as these particles being force fed and thus invading our very building blocks.
Finally, there is the case of the wider environment. None of these screens will stay put forever. Some will be ingested by touching of foodstuffs and dishes, It will rub off on our clothes and some will be inevitably be sloughed off directly in water, perhaps the shower. This will also happen via laundering of our clothes. In any case which will then proliferate and become part of the ingested substances by fish, crustaceans and the wider ecosystem such as the seabirds and in time us.
Some preliminary studies are becoming available finding and reinforcing these very concerns with particles turning up in human bloodstream, brain and even the placenta. See links at bottom for references.
At the very least the products should be clearly labelled to allow consumers to make an informed decision - a voice being put forth by ABC's Tony Eastley. Listen here.
In the mean time to stay safe in the sun, there's just something magic about a simple and time tested hat and a loose shirt. But if you want to swim these non-nano particle based sunscreen products keep you from becoming part of the experiment. Download your guide here.
You may additionally be interested is Sunlight and Cancer article on new research. It can be found here.
Studies, reports and references:
ﬁne particles. Oberdörster G, Oberdörster E, Oberdorster J. Environ. Health Perspect. 2005; 113: 823–39 Link
Potential photo-carcinogenic effects of nanoparticle sunscreens. Dai T Tran and Robert Salmon Link
Today Tonight story on dangers of Nano Sunscreens.
Study found tiny inhaled particles take easy route from nose to brain. Link
"Toxicity and penetration of TiO2 nanoparticles in hairless mice and porcine skin after subchronic dermal exposure". Wu, J; Liu, W; Xue, C; Zhou, S; Lan, F; Bi, L; Xu, H; Yang, X et al (2009). Link
Amid Nanotech's Dazzling Promise, Health Risks Grow namely the big killers of man, namely cancer, heart disease, neurological disease and ageing. Benedicte Trouiller. Link