Abstract
Benefits
of nanoscience and nanotechnology have been carefully implemented in many areas
of engineering to enhance the performance and quality of living conditions.
Even though the novel technology offers enormous benefits, the serious concerns
in that need to be addressed before commercializing the technology. Proper
implementation of the technology needs careful assessment of the impact on
environment, health hazards that may arise to the workers, users of the products and also to the environment. An attempt has been made to highlight the potential
hazards of nanotechnology in some of the areas and the possible remedial
measures, though the availability of the data to substantiate the claims are
very much limited.
Introduction
Nanotechnology
employs "bottom up" as well as "top down" approaches to produce nanomaterials in all the three dimensions. Nanoparticles, nanotubes and
carbon nanocrystals called Bucky Balls are now being manufactured in large quantities
[1, 2, 3]. Quantum effects begin to dominate the behaviour of matters at the
nanoscale and affect the optical, electrical and magnetic behaviours. Applications
of nanotechnology in terms of nanofibres, nanoparticles, nanocomposites and
nanotubes have been reviewed recently by many researchers [4, 5, 6, 7, 8]. Nanofibres,
nanotubes and nano-particles for imparting functional finishes find increased
applications in various forms of textile materials [5, 6, 7]. Though the
advantages of the nanomaterials are unending, the potential risks or hazards to
ecosystem or to the humans have drawn very little attention. Potential hazards
exist in production of man made fibres where nanosized dope additives are mixed
and, in the post manufacturing operations, where the continuous filaments are
cut into staple fibres. The post spinning processes are capable of producing respirable fibre flocks, tiny fibres that can result in diseases related to lungs [4,
9].
Even
though the nanomaterials appear to be a single class of material they differ in
terms of size, shape, surface area, chemical compositions, biopersistance [10];
the possible environmental and health impact need to be assessed for each type
of nanomaterial separately. Two factors that are responsible for occupational
risk of nano-particles include size and massive surface area, which can absorb
toxins and similar substances that can be transported into the body [11].
2.0
Potential Hazards
Proper
implementation of nanotechnology increases the exposure to nanoparticles through various routes like inhalation, ingestion, dermal and injection [11, 12, 13].
Factors that can alter the risk levels in nanoparticles include:
- The
quantum of material (mass / number of particles)
- Condition
of materials (solution / powder)
- Degree
of exposure
- Dosage
levels
The
particles of similar dimensions and elemental compositions can have different properties if the chemical architecture of such particles are modified e.g. diamond crystal and
bucky balls. Nanoparticles in the aggregates are likely exhibit the biological
effects that could be different from the bigger particles obtained from the
same substrate.
Nanomaterials,
like single walled carbon nanotubes, vary in terms of the physical forms and physical
properties, which make difficult to apply generic rules about the potential
health effects. A list of potential hazards due to nanomaterials has been
published regardless of their quantitative effects [14]. In many cases,
analogies have been drawn with results from very small particles present in large numbers in the urban air, and in some workplaces.
Also,
there is no established literature available regarding removal of nanomaterials
from human body, water or soil. Inhalation of the nano spheres and nanotubes
could cause serious troubles, especially for workers, who are involved in
manufacturing and handling.
