1 research outputs found
Gaining a Critical Mass: A Dose Metric Conversion Case Study Using Silver Nanoparticles
Mass concentration is the standard
convention to express exposure
in ecotoxicology for dissolved substances. However, nanotoxicology
has challenged the suitability of the mass concentration dose metric.
Alternative metrics often discussed in the literature include particle
number, surface area, and ion release (kinetics, equilibrium). It
is unlikely that any single metric is universally applicable to all
types of nanoparticles. However, determining the optimal metric for
a specific type of nanoparticle requires novel studies to generate
supportive data and employ methods to compensate for current analytical
capability gaps. This investigation generated acute toxicity data
for two standard species (<i>Ceriodaphnia dubia</i>, <i>Pimephales promelas</i>) exposed to five sizes (10, 20, 30,
60, 100 nm) of monodispersed citrate- and polyvinylpyrrolidone-coated
silver nanoparticles. Particles were sized by various techniques to
populate available models for expressing the particle number, surface
area, and dissolved fraction. Results indicate that the acute toxicity
of the tested silver nanoparticles is best expressed by ion release,
and is relatable to total exposed surface area. Particle number was
not relatable to the observed acute silver nanoparticle effects