US: Nanomaterial safety tested in a Petri dish

Nanomaterials, made of minuscule particles much smaller than those generally found in nature, are being developed by many industries as a means of dramatically improving everyday products. Yet, as with any scientific development, caution abounds regarding the possible health effects.

Fortunately, a definitive way of testing these concerns, without smearing nanoparticles on humans and animals, is now available. A researcher at the Lawrence Berkeley National Laboratory in San Francisco has developed a way to predict and evaluate the effects of exposure to a particular nanomaterial by using human skin cells in a Petri dish.

The scientist, Frank Chen, has found that once skin cells have been exposed to the nanoparticles, computerised image analysis can be used to gauge cell mortality, and genome analysis to see which genes have been switched on or off by exposure to the nanoproduct. Chen showed that cells are killed by large doses of exposure to nanoparticles, demonstrating that the products activate a stress response in some of our genes.

That is the bad news. More positively, Chen looked at his findings from another perspective: if certain nanoparticles are so toxic maybe they could do good and kill off cancer cells. His work follows the ringing of safety alarms especially when the cosmetics industry quietly launched a series of new nano-based products. After all, nanoparticles that are sealed within items such as televisions are one thing; the application of nanomaterial directly on to the skin is quite another.

Cosmetics companies are confident we will like them, however. This is mainly because products made with nano versions of titanium oxide – 100 nanometres in size (one nanometre is a billionth of a metre and a single human hair is around 50,000 nanometres wide) – allow cosmetics to be more effective.

Professor Lynn Frewer of University of Wageningen in the Netherlands notes: "The new generation of face creams and anti-ageing creams do have the capacity of genuine cosmetic enhancement, at least temporarily," she said. "This is because they can get into the subcutaneous part of the skin."

Sounding a warning, she added: "But if they can do that they can go even further."

*Mark Rowe is a specialist environmental journalist.