According to current knowledge in case it is properly placed into right materials it does not generate additional risk. Just like the little crystals of salt which get into the ground with the help of weaves. However many of the nanomolecules can have influance to our life.

Article:  http://www.nanonet.pl/index.php?option=com_content&task=view&id=368&Itemid=77

Thanks to: Prof. Dr Harald Kruga i dr Bernd Nowack