Abstract
The industrial production and commercial applications of titanium dioxide nanoparticles have increased considerably in recent times, which has increased the probability of environmental contamination with these agents and their adverse effects on living systems. This study was designed to assess the genotoxicity potential of TiO2 NPs at high exposure concentrations, its bio-uptake, and the oxidative stress it generated, a recognised cause of genotoxicity. Allium cepa root tips were treated with TiO2 NP dispersions at four different concentrations (12.5, 25, 50, 100 µg/mL). A dose dependant decrease in the mitotic index (69 to 21) and an increase in the number of distinctive chromosomal aberrations were observed. Optical, fluorescence and confocal laser scanning microscopy revealed chromosomal aberrations, including chromosomal breaks and sticky, multipolar, and laggard chromosomes, and micronucleus formation. The chromosomal aberrations and DNA damage were also validated by the comet assay. The bio-uptake of TiO2 in particulate form was the key cause of reactive oxygen species generation, which in turn was probably the cause of the DNA aberrations and genotoxicity observed in this study.
Highlights
TiO2 nanoparticles are extensively used in manufactured products such as cosmetics, sunscreen, toothpaste and pharmaceuticals and deemed to have potential applications in electronics, optics, genomics, proteomics and bio-analytical fields because of their larger surface area, enhanced chemical reactivity and easier penetration potential into the cells [1]
The effluents from wastewater treatment plant were reported to be the main entry points of TiO2 NPs to the aquatic environment reported a direct evidence for the leaching of engineered TiO2 NPs into the surface water from paints [3,4,5]
Characterization of TiO2 NPs Dispersion The hydrodynamic diameter of the particles in the test system is of prime importance
Summary
TiO2 nanoparticles are extensively used in manufactured products such as cosmetics, sunscreen, toothpaste and pharmaceuticals and deemed to have potential applications in electronics, optics, genomics, proteomics and bio-analytical fields because of their larger surface area, enhanced chemical reactivity and easier penetration potential into the cells [1]. National Institute for Occupational Health and Safety (NIOSH) has drafted a permissible exposure level (PEL) of 0.0015 mg/mL and a recommended exposure level (REL) of 0.0001 mg/mL for TiO2 NP based materials [6]. This necessitates the possible risks of TiO2 NP contamination to the surface water to be assessed [7]. The Allium cepa test has been the most established plant assay system appraised by the US-EPA GeneTox Program for environmental monitoring of the toxicants [8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
