Engineered Nanomaterials as Emerging Contaminants in Water - Nanotechnologies for Water Environment Applications - page 563

society (e.g., food container liners, clothing products, cosmetics, medical delivery or
diagnostic systems, etc) there is a high likelihood that NMs will be released into the air,
water or soil. Once in the environment, NMs are able to move between different media
phases. For example, stormwater will transport NMs from the atmosphere (i.e., airshed)
or land-deposited NM (i.e., settled aerosols, soil amendments, agricultural products) into
surface waters or groundwater systems. NMs in rivers and lakes will associate with
suspended sediment, porewaters or plants and may transition from the water column into
soil systems. NMs may bioaccumulate through the food chain. Eventually engineered
NMs may unexpectedly end up back in human drinking water sources or food sources.
Thus avenues exist for engineered NMs to affect ecosystem health and processes, or
affect humans.

A A A A

B B B B

C C C

100 nm 100 nm 100 nm 100 nm

20 nm 20 nm 20 nm 20 nm

1E+02 1E+02 1E+02

Hematite
Fe2O3
CdTe Quantum Dots
Fullerene (nC60)

Hematite
Fe2O3
CdTe Quantum Dots
Fullerene (nC60)

Hematite
Fe2O3
CdTe Quantum Dots
Fullerene (nC60)

E E E

D D

D D D

1E+01 1E+01 1E+01

1E+00 1E+00 1E+00

1E-01 1E-01 1E-01

1E-02 1E-02 1E-02

1E-03 1E-03 1E-03

1E-04 1E-04 1E-04

D D D

1E-05 1E-05 1E-05

C C C

1 1 1 10 10 10 100 100 100 1000 1000 1000

Particle Diameter (nm) Particle Diameter (nm) Particle Diameter (nm)

Figure 16.2 Electron micrograph of (A) lab-synthesized hematite, (B) commercially
available iron oxide NMs, and (C) aggregated nC 60 . Dynamic light scattering (DLS) for
four NMs is shown in the bottom plot.