Ecotoxicology of Manufactured Nanoparticles - Environmental and Human Health Impacts of Nanotechnology - page 265

Atmospheric deposition

Soil application

Effluent discharge

Surface runoff

Road runoff

Groundwater discharge

Accidental spillage

Figure 7.2 Potential sources of manufactured nanoparticles in the environment.

The exposure of organisms to nanoparticles will, of course, depend on their
release into the environment and their environmental concentrations. The potential
sources of manufactured nanoparticles to the environment are illustrated schemati-
cally in Figure 7.2. Like other industrially-derived chemicals, manufactured nanopar-
ticles may be discharged to the environment at several stages in their life cycle. This
includes during manufacture, transport (accidental spillage), use in industry or by
consumers, and during disposal.
In this chapter, scientifi c literature to date on the ecotoxicology of manufactured
nanoparticles is reviewed and critical recommendations made for further studies
and the development of ecotoxicological test procedures. Background chemical and
physical information on manufactured nanoparticles of relevance to ecotoxicolo-
gists is also provided.

7.2 Physico - Chemical Transformation of Nanoparticles

The detailed chemistry of manufactured nanomaterials and analytical methods to
characterise the properties manufactured nanoparticles (e.g. particle size, zeta
potential) are covered in chapters 5, 6 and 8. A summary is given here on important
physical and chemical processes that may modulate nanoparticle toxicity, both in
the environment following release of the nanoparticulates and also over the dura-
tion of the ecotoxicity tests performed in the laboratory. The basic processes affect-
ing the fate and transport of nanoparticles in aquatic systems are illustrated in
Figure 7.3 .