We asked ABC's Alan Sunderland for comment.
UPDATE: Right on cue ABC cover the story and no surprise they give prominence to activist opinions of a career environmental campaigner over the experts. In comments FOE's Louise Sales further misrepresents the results of the recent work and further exaggerates the risks of nano-particles.
We asked report author Simon James for more information. Here is his reply:
Here is some clarification about the current work; Zn is an essential nutrient, our bodies must have Zn in order to function (similar to iron or calcium). In 2013 the Therapeutic Goods Administration (TGA) released a review of the literature (attached) which concluded ZnO nanoparticles present in sunscreens pose no risk to consumers when used as intended. Our manuscript dose acknowledges previous work which demonstrated that a very, very small amount of Zn from ZnO nanoparticles present in sunscreen can penetrate the skin when used in the field (attached). I want to be very clear that this work showed that the Zn from ZnO nanoparticles made up less than 0.001% of the total Zn detected. This is not a level of Zn which is associated with any safety concerns (to be honest I am impressed the authors could even make such a precision measurement). However, given the limitations of doing a field studies the authors could not conclude whether the Zn made it into the body as part of intact nanoparticles or in some other form. Our study built on this finding by asking the question, “If the nanoparticles do penetrate the skin can a macrophage break these objects down?” We are not the first to try and answer this question, indeed our work is merely a single study adding to a much larger body of work but we were able to go further than other groups and show direct evidence for cell mediated breakdown of ZnO nanoparticles.
Recent media reports (http://www.theage.com.au/national/scientists-discover-nanoparticles-in-sunscreen-are-harmless-20140127-31iy4.html) that “nanoparticles in sunscreen are harmless” on the basis of a recently published study (http://pubs.acs.org/doi/ipdf/10.1021/nn403118u) don’t reflect the paper’s own conclusions nor the current state of the science.
ReplyDeleteWhilst the results of this lab study study are interesting, more studies are needed reflecting real life conditions before any conclusions about the safety of nano zinc oxide in sunscreen can be drawn. Importantly, the paper draws no conclusions about the safety of nano-ingredients in sunscreen and also doesn’t look at other nano sunscreen ingredients such as titanium dioxide and cerium oxide.
What the study does acknowledge is that nano-ingredients can penetrate the skin and get into the bloodstream. This is something our sunscreen regulator the Therapeutic Goods Administration has so far denied.
The view that nano-ingredients in sunscreen are safe is not shared by the European Commission's Scientific Committee on Consumer Safety. This body recently recommended that certain nano titanium dioxide (TiO2) ingredients not be used in sunscreen because they strongly react with sunlight to produce free radicals and that nano TiO2 and nano zinc oxide (ZnO) not be used in powder or sprayable products because of the toxicity risk associated with inhalation.
A recent Italian study using pig ear skin found that nano titanium dioxide damaged the outer layer of skin. The researchers warned that this could allow nanoparticles and other unwanted chemicals to penetrate the skin - posing a potential human health risk.
The European Chemical Agency (ECHA) is currently reviewing the safety of titanium dioxide (including the nano form) because of concerns in may be harmful to the environment and human health. Meanwhile our regulators here have taken no action to remove these ingredients from sunscreen.
Report author versus ABC "free thinker." Hmmm....
DeleteReport Author = 1. Journo = 0.
Louise it seems you have misrepresented the recent work. Report author Simon James provides the following comments:
ReplyDelete"Here is some clarification about the current work; Zn is an essential nutrient, our bodies must have Zn in order to function (similar to iron or calcium). In 2013 the Therapeutic Goods Administration (TGA) released a review of the literature (attached) which concluded ZnO nanoparticles present in sunscreens pose no risk to consumers when used as intended. Our manuscript dose acknowledges previous work which demonstrated that a very, very small amount of Zn from ZnO nanoparticles present in sunscreen can penetrate the skin when used in the field (attached). I want to be very clear that this work showed that the Zn from ZnO nanoparticles made up less than 0.001% of the total Zn detected. This is not a level of Zn which is associated with any safety concerns (to be honest I am impressed the authors could even make such a precision measurement). However, given the limitations of doing a field studies the authors could not conclude whether the Zn made it into the body as part of intact nanoparticles or in some other form. Our study built on this finding by asking the question, “If the nanoparticles do penetrate the skin can a macrophage break these objects down?” We are not the first to try and answer this question, indeed our work is merely a single study adding to a much larger body of work but we were able to go further than other groups and show direct evidence for cell mediated breakdown of ZnO nanoparticles."