I see that the degree of that danger depends mainly in our knowledge towards the environment itself and our adaptability to new things and phenomena that arise as a result of working in nanoscale . in other word, the effect of nanomaterials may be indirect towards the danger of the nature , that danger can’t be direct (more or less) because the nature itself is nanomaterials , moreover the nature is our instructor and inspirer to develop more in nanotechnology over its lengthy journary