189
nanohybrids materials have been produced for environmental technologies, making
their environmental health and safety evaluation very important (Saleh et al. 2015).
Recent findings indicate that the combination of titanium dioxide nanoparticles with
carbon nanotubes (MWCNT) allows a greater photosensitivity (Ling et al. 2016). In
order to understand the role of titanium dioxide–MWCNT in the environment, Silva
et al. (2017a, b) evaluated the exposure of Danio rerio embryos. There was no acute
toxicity, nor sublethal effects in Danio rerio embryos, until 100 mg L
−1
when hatching rate and growth were observed. So, this nanohybrid material probably presents
low toxicity (Côa et al. 2017). On the other hand, activated carbon from pyrolysed
sugarcane bagasse (ACPB) with silver nanoparticles (ACPB-silver nanoparticles)
presented environmental risks, with toxic effect to the aquatic organism Hydra
attenuata (LC 50 1.94 mg L
−1
), which raises concern about the environmental implications of activated carbon materials modified with silver nanoparticles (Gonçalves
et al. 2016).
7.3.3 Nanostructure Risk Assessments and Safety Analysis
An essential step in the development of products based on nanotechnology is
the assessment of their potential risks and safety, including an evaluation of the
potential impact of nanoparticles and practices related to their application on human
or animal health and environmental destination.
While the scientific community points to a number of environmental advantages
for the use of nanotechnology, on the other hand, there is still great difficulty in
specifying what happens in air, water, and soil when nano-sized particles are potentially polluting waste. The replacement of some practices for these technologies and
their dissemination allows one to question what are the environmental and social
impacts of these technologies to the adopters and direct and indirect users. However,
research in these yet incipient fields prevents us from scaling the impacts of these
products to the environment and to society.
With regard to hazard analysis, as new nanomaterials are being developed at high
rates and for different applications, interest has surfaced in elucidating the safety of
these materials. Considering that better understanding and refinement in the formulation stage of the risk assessment problem may help reduce risk, the development
of nanoparticle risk indicators can be an ally in the decision process, supporting the
safety analysis of the development of nanomaterials to their release for human consumption or application to the environment.
The gap between risk assessors and researchers working in the field of nanotechnology makes difficult to develop proper indicators and reliable data to support
safety regulations. The risk refers to the likelihood of an injury occurring under the
conditions of use and may be reduced or increased according to the potential exposure. Therefore, the risk is the product of the hazard (adverse effect) relationship of
a compound and its exposure. Consequently, a better understanding and refinement
7 Toxicity of Engineered Nanostructures in Aquatic Environments
nanohybrids materials have been produced for environmental technologies, making
their environmental health and safety evaluation very important (Saleh et al. 2015).
Recent findings indicate that the combination of titanium dioxide nanoparticles with
carbon nanotubes (MWCNT) allows a greater photosensitivity (Ling et al. 2016). In
order to understand the role of titanium dioxide–MWCNT in the environment, Silva
et al. (2017a, b) evaluated the exposure of Danio rerio embryos. There was no acute
toxicity, nor sublethal effects in Danio rerio embryos, until 100 mg L
−1
when hatching rate and growth were observed. So, this nanohybrid material probably presents
low toxicity (Côa et al. 2017). On the other hand, activated carbon from pyrolysed
sugarcane bagasse (ACPB) with silver nanoparticles (ACPB-silver nanoparticles)
presented environmental risks, with toxic effect to the aquatic organism Hydra
attenuata (LC 50 1.94 mg L
−1
), which raises concern about the environmental implications of activated carbon materials modified with silver nanoparticles (Gonçalves
et al. 2016).
7.3.3 Nanostructure Risk Assessments and Safety Analysis
An essential step in the development of products based on nanotechnology is
the assessment of their potential risks and safety, including an evaluation of the
potential impact of nanoparticles and practices related to their application on human
or animal health and environmental destination.
While the scientific community points to a number of environmental advantages
for the use of nanotechnology, on the other hand, there is still great difficulty in
specifying what happens in air, water, and soil when nano-sized particles are potentially polluting waste. The replacement of some practices for these technologies and
their dissemination allows one to question what are the environmental and social
impacts of these technologies to the adopters and direct and indirect users. However,
research in these yet incipient fields prevents us from scaling the impacts of these
products to the environment and to society.
With regard to hazard analysis, as new nanomaterials are being developed at high
rates and for different applications, interest has surfaced in elucidating the safety of
these materials. Considering that better understanding and refinement in the formulation stage of the risk assessment problem may help reduce risk, the development
of nanoparticle risk indicators can be an ally in the decision process, supporting the
safety analysis of the development of nanomaterials to their release for human consumption or application to the environment.
The gap between risk assessors and researchers working in the field of nanotechnology makes difficult to develop proper indicators and reliable data to support
safety regulations. The risk refers to the likelihood of an injury occurring under the
conditions of use and may be reduced or increased according to the potential exposure. Therefore, the risk is the product of the hazard (adverse effect) relationship of
a compound and its exposure. Consequently, a better understanding and refinement
7 Toxicity of Engineered Nanostructures in Aquatic Environments