Nanomaterials found in consumer products damage cell DNA.
Karlsson, HL, P Cronholm, J Gustafsson and L Moller. 2008. Copper oxide nanoparticles are highly toxic: a comparison between metal oxide nanoparticles and carbon nanotubes. Chemical Research in Toxicology online August 19.
Many nanomaterials currently used in sunscreens and other consumer products killed or damaged the DNA of human lung cells when tested in a laboratory. These results show the immediate need to test nanomaterials for safety before they are used in consumer products. The new study reveals the unique toxic nature of different types of nanomaterials, a class of materials that are literally defined by their very small size. Nanoparticles are used in a growing number of everyday products, such as sunscreens, cosmetics and electronics, so exposure to these mostly untested materials is widespread. In this study, Swedish researchers exposed human cells from the surface of lungs to eight different types of nanomaterials and measured DNA damage and indicators of stress. The researchers found that different nanomaterials cause different types of adverse responses in the lung cells. Two ingredients found in sunscreens and cosmetics, zinc oxide and titanium dioxide nanoparticles, killed cells or damaged the DNA. Copper based nanomaterials were the most toxic, causing DNA damge, oxidative damage and cell death. Two types of iron oxide nanoparticles that were tested did not result in toxic effects, however a composite nanomaterial made of copper, zinc and iron was able to induce DNA damage. DNA damage also resulted from exposure of the lung cells to carbon nanotubes even at the lowest dose tested.