A Review of Toxicity of Some Conventional Nanomaterials

Increased production and use of nanomaterials has led to an ever growing exposure of living organisms to these substances. Limited knowledge about possible toxicity of nanomaterials and their potential to harm living creatures is becoming a serious concern. To address this problem, there is a need for development of diagnostic methods enabling effective determination of potential toxicity of nanomaterials. On the other hand, developing appropriate test methods is contingent on identifying cellular mechanism underlying toxicity of nanomaterials. This study reviews toxicity of some of the most widely used nanomaterials. According to the literature, Iron oxide nanoparticles can augment rate of cell death through oxidative stress and lipid peroxidation. Exposure to zinc oxide, gold and silver nanoparticles can result in cell death via mitochondrial dysfunction, expression of abnormal protein in cells, and altering the patterns of gene expression, respectively. Likewise, carbon nanotubes can lead to an increased rate of cell death through the reduction of membrane fluidity, thereby destroying cell membrane. Our literature review identified a lower toxic effect for nanotubes as compared with other nano-structures. Regarding the evident high toxicity of nanomaterials, caution must be exercised in irregular production and use of these substances in the industry. In addition, from the health and environmental standpoints, carbon nanotubes are the preferable nano-structures for development of nanotechnologies regarding their lower toxicity in comparison with other nanomaterials.