06-08-2013, 04:43 PM
An assessment of phytotoxicity of nanomaterials for food safety
ABSTRACT
Increased applications of engineered nanomaterials have created great concern about their toxicity among plants and humans. Nanomaterials, like carbon nanotubes (CNTs), magnetic nanoparticles, aluminium based nanoparticles, zinc based nanoparticles (ZnO etc.), copper nanoparticles (Cu NPs) and silver nanoparticles (Ag NPs) have tremendous applications in agriculture and food sector. This trend has given rise to several questions regarding the safety aspects of nanomaterials and their integration with food and fodder. To address this issue, a number of investigators around the globe have taken initiative to reveal the phenomena of phyto-toxity of nanomaterials. It has been reported that root elongation in lettuce and tomato get inhibited with CNTs. Root growth of radish and rape incubated in nano-Zn suspension was significantly inhibited. The cytotoxic and genotoxic impacts of Ag NPs were already reported on onion plant i.e. they impaired the stages of cell division and caused cell disintegration. Mung bean was found to be more sensitive to Cu nanopaticles than wheat crop and growth inhibition of seedlings was observed. In recent years, great attention has been brought to genetic effects of ferrofluids; that lead to chromosomal aberrations in young plants. Pure alumina nanoparticles without any modifications reduced root elongation in plants including Cucumis sativus, Daucus carota and Brassica oleracea. The studies carried out so far strongly suggest for an assessment of cytotoxic and genotoxic evaluations of nanomaterials with special reference to their uptake, translocation and distribution in different plant tissues. This phyto-toxicity evaluation holds the promise of controlled use of nanoparticles and their site targeted delivery for improved plant disease resistance, efficient nutrient utilization and enhanced plant growth.