Editorial: Nanotoxicology and Environmental Risk Assessment of Engineered Nanomaterials (ENMs) in Plants

In the last two decades, the development and application of nanotechnology—the science of small—has increased dramatically, impacting sectors as far reaching as medicine (including disease treatment and diagnosis), energy, communications, water treatment and food production. In spite of these incredible advances, the general consensus among the scientific community is that our understanding of the fate and effects of these novels materials in the environment is inadequate. Given the level of current and projected exposure to both human and non-human receptors, this basic lack of understanding with regard to ENM environmental health and safety (EHS) is highly disconcerting. The articles contributed as part of this research topic are indicative of the current work being done to begin to address some of these key knowledge gaps, specifically focusing on impacts of ENM exposure to terrestrial plant species and food crops. The papers address a range of topics, including effects on key plant species measured at both the physiological and molecular level, and present a description of some important analytical platforms by which to assess exposure; single particle inductively coupled mass spectrometry (sp-ICP-MS) and proteomics. Two articles specifically address ENM impacts on foods nutritional content and on dietary intake. A final review article assesses the current use of carbon nanomaterials in agriculture, including a description of key research areas where more work is sorely needed. Specifically, Mukherjee et al. investigated the role of coating type on the toxicity and accumulation of ZnO nanoparticles (NP) to soil-grown green pea (Pisum sativum L.). Importantly, this work as conducted to analyze the impact of exposure during the full life cycle of the plant and included a direct comparison of the nanoparticles against corresponding bulk and ion controls. The authors report that exposure to the nanoparticle form uniquely impacted Zn levels in the plant, as well as photosynthetic pigments but that protein and carbohydrate profiles were largely unaffected. However, among the nanoparticle types, overall phytotoxicity and seed nutritional quality was impacted by particle coating. Mattiello et al. investigated the phytotoxic and genotoxic effects of CeO 2 and TiO 2 NP exposure on barley under hydroponic conditions. The authors measured genotoxicity by Randomly Amplified Polymorphism DNA and by the mitotic index. The authors reported greater overall toxicity from CeO 2 as compared to TiO 2. The authors also observed changes in RAPD banding and in the mitotic index upon NP exposure, as well as NP-specific effects on cellular …