4. WHAT
IS“NANOMATERIALS”?
Nanomaterials is a field that takes a materials
science-based approach to nanotechnology. It
studies materials with morphological features
on the nanoscale, and especially those that
have special properties stemming from their
nanoscale dimensions.
Nanoscale is usually defined as smaller
than a one tenth of a micrometer in at least
one dimension, though this term is
sometimes also used for materials smaller
than one micrometer.
5. WHAT IS TOXICOLOGY?
Toxicology is a branch of biology,
chemistry, and medicine concerned with
the study of the adverse effects of
chemicals on living organisms.
It is the study of symptoms, mechanisms,
treatments and detection of poisoning,
especially the poisoning of people.
It was found that various disciplines of
TOXICOLOGY were under study.
6. DISCIPLINES OF
TOXICOLOGY
Aquatic toxicology
Chemical toxicology
Ecotoxicology
Environmental toxicology
Forensic toxicology
Medical toxicology
7.
8. NANOTOXICOLOGY
Nanotoxicology is the study of the
toxicity of nanomaterials.
Because of quantum size effects and
large surface area to volume ratio,
nanomaterials have unique properties
compared with their larger counterparts.
9. Nanotoxicology is a branch of
bionanoscience which deals with the
study and application of toxicity of
nanomaterials.
Nanomaterials, even when made of inert
elements like gold, become highly active
at nanometer dimensions, these exhibit
toxicity.
10. Nanotoxicological studies are intended
to determine whether and to what extent
these properties may pose a threat to
the environment and to human beings.
For instance, Diesel nanoparticles have
been found to damage the
cardiovascular system in a mouse
model.
11. REASONS FOR TOXICITY OF
NANOPARTICLES
As it is well known fact that, when the
particle size of a material decreases, its
surface area to volume ratio increases,
leading to SPECIAL characteristic
properties as well different adverse
effects on ENVIRONMENT.
Due to the quantum size of these
nanoparticles these possess toxicity.
12. Like all nanomaterials, iron-based
nanoparticles ,like these can vary in their
toxicity, depending on their chemical
composition, coating, size, and shape.
To better assess the biological effects of
nanomaterials, researchers have
developed a rapid screening tool that can
evaluate large numbers of nanomaterials
and identify groups of materials that are
more likely to pose a risk.
13. David Rand, Robert Hurt and coworkers describe their
experiments, in which they exposed fruit fly larvae and adults to
various types of carbon nanomaterials. In case of the larvae,
some nanomaterial was accumulated in tissues, but had no
impact on the development or survival. If they exposed adult
flies to carbon nanomaterial, this exposure led to the flies’ death
within hours, previously impairing their mobility. SEM images of
the flies show severe damage to the flies legs and feet for
example. Referring to the authors, toxicity might be due to the
carbon nanomaterial adheres to the flies’ eyes and – more
problematic – to their breathing holes.
This result is also in line with the finding, that small aggregates
(e.g. carbon black; single-walled nanotubes) show higher toxicity
than than nanomaterials with larger aggregate sizes.
Furthermore, the scientist were able to show that the
contaminated flies are spreading the nanomaterials to ‘clean’
flies while grooming themselves.
17. As the developing concepts in
nanomaterials have their advantages, it
also has disadvantages.
So its necessary for all to concentrate
on the second side of the coin.
The researches all over the world begin
to put forward their efforts to create a
new generation of science with minimum
or without adverse effects.