37
have proven that nanomaterials may be toxic to human tissue and cause increasing
oxidative stress, inflammatory cytokine production, and cell death (Oberdörster
et al. 2005). Also, nanomaterials have potential to cause DNA mutation in the cells
(Geiser et al. 2005). Although size is an important parameter determining the potential negative effects on health, there are some other parameters such as shape, aggregation and solubility, surface structure and charge, and the presence of functional
groups of other chemicals that may cause adverse effects on health (Nel et al. 2006;
Magrez et al. 2006). Studies have confirmed that shape and size of the nanomaterials have a different effect on the biological activity. For example, Pal et al. demonstrated that interaction of nanoparticles with E. coli is dependent on their shape (Pal
et al. 2007). In another research, Journeay et al. verified that rosette nanotubes
which are water-soluble structures have low toxicity to lungs because of their biological shape (Journeay et al. 2008). Different forms of nanomaterials cause different toxicological effects on health. In the light of these findings, each nanomaterial
must be evaluated separately and all properties should be taken into consideration
for health effect.
Humanity has limited evolutionary experience of nanomaterials with few exceptions such as nanoparticles from marine aerosols, viruses, and some engineered
nanoparticles. As humanity evolved with regard to knowledge, they have taken control over the nature more effectively. Thus, they have learnt to create various nanostructures. Through the course of the handling nanoparticles, they are exposed to
nanoparticles in each step. Since the area is at its early stage, there has been no
comprehensive study. Thus, it is quite difficult to figure out what will be the consequences of nanotechnology. The rapid evolution of nanotechnology and its products
make the task much more challenging. A variety of nanomaterials have already been
manufactured and the number of products and varied structures such as buckminsterfullerene, carbon nanotubes, micelles, self-assembled monolayers, dendrimers,
and aerogels seem to increase. Although it is too fast evolving area to catch up with,
it is important to make a start in order to handle it safely. Numerous variations of
nanoparticles and their structure probably have different effects on health and environment. This is mainly due to substantially varied properties. Below are summarized some available impacts of nanomaterials on health and environment.
Living beings have been exposed to nanoparticles which are man-made or
nature-made through history. It is more likely that living beings have adapted to
nanoparticles produced by natural events, but this is not true for newly engineered
nanoparticles. Thus, at this point, we should be aware of the probable implications
of nanomaterials. The safety of handling nanoparticles remains controversial due to
lack of studies and contradictory results. Here is a summary of both in vivo and
in vitro studies.
Since properties of nanoparticles are strongly dependent on their size, many biological mechanisms such as endocytosis and cellular uptake behaviors are also
determined by the size of nanoparticles (Moser et al. 2016). Generally, nanoparticles can influence biological systems by modifying molecules or interfering critical
processes. Thus, it becomes important to have knowledge of whether they are toxic
or not. Engineered nanoparticles can lead to formation of free radicals, which are
2 Nanomaterials and Human Health
have proven that nanomaterials may be toxic to human tissue and cause increasing
oxidative stress, inflammatory cytokine production, and cell death (Oberdörster
et al. 2005). Also, nanomaterials have potential to cause DNA mutation in the cells
(Geiser et al. 2005). Although size is an important parameter determining the potential negative effects on health, there are some other parameters such as shape, aggregation and solubility, surface structure and charge, and the presence of functional
groups of other chemicals that may cause adverse effects on health (Nel et al. 2006;
Magrez et al. 2006). Studies have confirmed that shape and size of the nanomaterials have a different effect on the biological activity. For example, Pal et al. demonstrated that interaction of nanoparticles with E. coli is dependent on their shape (Pal
et al. 2007). In another research, Journeay et al. verified that rosette nanotubes
which are water-soluble structures have low toxicity to lungs because of their biological shape (Journeay et al. 2008). Different forms of nanomaterials cause different toxicological effects on health. In the light of these findings, each nanomaterial
must be evaluated separately and all properties should be taken into consideration
for health effect.
Humanity has limited evolutionary experience of nanomaterials with few exceptions such as nanoparticles from marine aerosols, viruses, and some engineered
nanoparticles. As humanity evolved with regard to knowledge, they have taken control over the nature more effectively. Thus, they have learnt to create various nanostructures. Through the course of the handling nanoparticles, they are exposed to
nanoparticles in each step. Since the area is at its early stage, there has been no
comprehensive study. Thus, it is quite difficult to figure out what will be the consequences of nanotechnology. The rapid evolution of nanotechnology and its products
make the task much more challenging. A variety of nanomaterials have already been
manufactured and the number of products and varied structures such as buckminsterfullerene, carbon nanotubes, micelles, self-assembled monolayers, dendrimers,
and aerogels seem to increase. Although it is too fast evolving area to catch up with,
it is important to make a start in order to handle it safely. Numerous variations of
nanoparticles and their structure probably have different effects on health and environment. This is mainly due to substantially varied properties. Below are summarized some available impacts of nanomaterials on health and environment.
Living beings have been exposed to nanoparticles which are man-made or
nature-made through history. It is more likely that living beings have adapted to
nanoparticles produced by natural events, but this is not true for newly engineered
nanoparticles. Thus, at this point, we should be aware of the probable implications
of nanomaterials. The safety of handling nanoparticles remains controversial due to
lack of studies and contradictory results. Here is a summary of both in vivo and
in vitro studies.
Since properties of nanoparticles are strongly dependent on their size, many biological mechanisms such as endocytosis and cellular uptake behaviors are also
determined by the size of nanoparticles (Moser et al. 2016). Generally, nanoparticles can influence biological systems by modifying molecules or interfering critical
processes. Thus, it becomes important to have knowledge of whether they are toxic
or not. Engineered nanoparticles can lead to formation of free radicals, which are
2 Nanomaterials and Human Health