EMERGING CONCERNS - Marine Pollution: What Everyone Needs to Know - page 130

toxic to marine life. A ield of nanoecotoxicology is develop-
ing. Investigating effects of NPs in the aquatic environment
is important, since it receives runoff and wastewater from
domestic and industrial sources containing nanoparticles.
While metal NPs may have fates similar to other forms of
the same metal, metal NPs tend to be more toxic than regular
forms of the metal. However, metals in NPs may be tightly
bound to the core material and not readily dissociated. In the
aquatic environment NPs tend to agglomerate, which means
they will settle into sediments and be taken up by organisms.
Danielle Cleveland and colleagues compared the environmen-
tal fate of nanosilver in consumer products, two silver (Ag)
NP standards, and ionic silver (Ag + ) in estuarine mesocosms
containing a variety of species, and found that the consumer
product (a stuffed teddy bear) released high amounts of Ag
(>80%) over 60 days, which moved from the water into clams,
grass shrimp, mud snails, cordgrass, biofilms, and sediment.
Ag was initially adsorbed from the water onto the sediment,
then from there moved into the clams and other residents in
the tank. Significant amounts were taken up into animals by
consuming sediments and smaller organisms.
Research is ongoing to develop methods to measure NPs
in water and sediment, and to determine their environmen-
tal occurrence, the sources and pathways of their release, their
transport and fate, and their potential effects. There is a need
to develop standardized analytical techniques, understand the
role of wastewater treatment plants on their environmental
fate, and determine mechanisms of their transport and fate in
the environment. This will be difficult, since so many chemi-
cals can be in the nanoparticle form, but will not be able to be
measured in the same way.
NPs accumulate in estuarine organisms, with effects
largely unknown. A limited number of studies have shown
toxic effects, but the effects are highly specific to the chemi-
cal nature of the NP and the organism. Fullerenes and nano-
tubes produced adverse effects on fish, and metal NPs caused