ABSTRACT
NPs are dened as particles with at least one of the three dimensions in the range from 1 nm to tens of nanometers (Hochella et al., 2008). ¤ese natural NPs (NNPs) are ubiquitous in terrestrial ecosystems and have been present for many years. However, it is very likely that in the near future the NP population (in terms of types and concentration) in soils will grow considerably and even unconventionally, that is, with not easily determined trends, when manufactured NPs (MNPs), which are engineered for di¦erent purposes in many areas of human activities, will enter the terrestrial ecosystems and become ENPs. ¤e focus of this chapter is only on ENPs that are present in terrestrial systems and not on those in other environmental media, such as atmosphere or hydrosphere.
