Page 52 - ACCB 2020

Revista de la Asociación Colombiana de Ciencias Biológicas
issn impreso 0120-4173, issn en línea 2500-7459
mation of micronuclei. The reason behind such activity (water fl ea), resulting in toxicity (177). Furthermore,
was claimed to be the increased intracellular binding of TiO NPs when mixed with lead acetate (PbAC) was
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BPA to TiO NP. reported to increase the generation of reactive oxygen
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species (ROS), intracellular superoxide dismutase, glu-
Dichloro diphenyl trichloroethane (p,p′-DDT) was wi- tathione, and cytotoxicity in human embryo hepatocyte
dely used as an effi cient insecticide. It was shown to cells (178). These observations suggested an increased
possess a genotoxic and endocrine disruptive effect on oxidative stress due to the interaction of TiO NP with
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humans and other organisms (169–171). Therefore, to PbAC.
avoid its harmful effect its removal from the environ-
ment is essential. TiO NP has been shown to degrade it. Arsenic is also a water pollutant. Exposure to arsenic
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But surprisingly it has been observed that the combined can result in various ailments such as cancer, cardiovas-
action of TiO NP and p,p′-DDT synergistically increa- cular and metabolic diseases (179). TiO NP can be used
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sed genotoxicity, oxidative stress, DNA, and chromoso- to reduce the arsenic level from water because it acts
mal damage in L-02 cells (168). Such interaction thus as photocatalytic oxidant and absorbent for As (180).
poses an environmental threat. However, the literature Through a study, Wang et al (181) demonstrated that
on the effect of surfactants in combination with nano- TiO NP and As were nontoxic to Ceriodaphnia dubia
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particles is inadequate. Therefore, there is a need to (water fl ea) at 400 mg/L and 3.68±0.22 mg/L respec-
highly explore this aspect. tively after their independent exposure. Exposure of
both materials in combination increased the toxicity at
5.2. Interaction of nanoparticles with ions and inor- the lower concentration of 50 mg/L TiO NPs and 1.43
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ganic compounds mg/L As. Similarly, TiO with humic acid also affects
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The interaction of nanoparticles with various metal the accumulation of Cadmium in zebrafi sh. TiO NP of
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ions and toxic inorganic compounds can both increa- 21nm in diameter at the concentration of 5-20 mg/L in
se and decrease their toxicity. Sodium fl uoride (NaF) humic acid-containing water has been reported to alter
and TiO NPs are additive materials used in toothpas- the Cd uptake(182).
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te (172,173). Nevertheless, Xie et al (174) studied the
combined effects of both of them on 16-HBE, the hu- Polyacryl coated TiO NP can also be used to remove Cd
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man bronchial epithelial cells. After exposure, the lyso- from water. The coated TiO NPs are much safer than
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zymes are adsorbed on the surface of TiO NPs. The the uncoated, as mentioned above. This is because it
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adsorption might be due to the electrostatic attraction is found that Cd absorbs quickly on polyacryl coated
and hydrogen bonds between the lysozymes and the na- TiO NP thereby removing them from the aquatic en-
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noparticles. It implies that such interaction could give vironment and thus reducing the incidence of Cd toxi-
rise to harmful effects on the exposed cells. city. Additionally, as per the experiment performed on
Chlamydomonas reinhardtii the electrostatic and steric
6. Generation of complex pollutants repulsion between algal cells and TiO NP minimizes
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Through various usage, nanoparticles are reaching to the chances of cell – nanoparticle interaction, ultima-
water bodies and thus affecting the aquatic environ- tely reducing the chances of nanoparticle toxicity (183).
ments. As discussed, ultimately these nanoparticles Various studies are reporting the combined toxicity of
certainly mix and interact with the other water pollu- a nanoparticle with a pollutant, there is also a need to
tant and form the complex compounds, which might be study the combined toxicity of one type of nanoparticle
more toxic than nanoparticles and the pollutant alone with another type of nanoparticle in the aquatic envi-
(175). It is a well-known fact that copper is essential for ronment. It will open up a new avenue as a water body
the normal functioning of our homeostasis. At lower do- including sewage water and/or drinking water might
ses, it is harmless to the human body. Whereas, at a high possess more than one type of nanoparticles. Therefore,
dose, copper could be toxic to humans. At high doses, there are possibilities to have altered toxicity of various
it has demonstrated to cause immunotoxicity in mice nanoparticles in combination with aquatic life. Figure 3
(176). However, TiO NPs with copper have increased is the summary of the comparative activity and result of
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bioaccumulation of copper in freshwater D. magna nanoparticles and pollutants alone and in combination.

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Rev. Asoc. Col. Cienc.(Col.), 2020; 32: 42-62.