Environmental and Human Health Impacts of Nanotechnology

Manufactured nanoparticles (NPs) are usually defi ned as materials purposefully produced by human activity and which have at least one dimension between 1 and 100 nm. It is important to distinguish NPs by source; the main other NPs are incidental: that is produced indirectly by human activities including fossil fuel combustion, and natural: that is produced by processes such as chemical hydrolysis, weathering and microbial action. Other size - based defi nitions of NPs exist and there are a wide variety of material types which fall within this defi nition. Nanoscience, which is the science dealing with nanoscale materials, can be seen as simply a subset of traditional colloids science. Nevertheless, a large number of novel processes occur below this size due to effects such as exponential increases in specific surface area and surface energy, quantum effects such as quantum confi nement (where wave functions are constrained by the small particle size) and under - coordination of bonds at the particle surface. Processes which occur in this size range are thus different in many ways to traditional colloid chemistry and, in general, the differences become more pronounced at smaller sizes. The current interest in nanotechnology is due to these novel properties and their exploitation in industrial processes and consumer products. Huge and exponentially growing research and development funding from government and private sources has been spent to better develop and exploit these potential uses and Nps are now used widely.