Engineered Nanoparticles In the Environment: Potential Risks and Challenges.

Engineered nanoparticles (1-100 nm) have been used in increasing number of consumer products (such as socks, shampoos and paints) and other applications (e.g., biomedical, electronic and environmental). As a result, engineered nanoparticles (ENPs) will be inevitably released into the environment from accidental release, intentional application, and disposal at the end of life-cycle of the ENPs-containing products. The release of ENPs raises concerns over their environmental impact and health risk. In this work, different types of ENPs were examined for their uptake by and distribution in plants using spectroscopic and microscopic techniques. It is found that ENPs can be taken up by plants including agricultural crops, posing potential problem to food safety. The uptake of ENPs is plant species- and particle property-dependent. The data also showed that ENPs were generally more toxic to the tested bacterial species than their bulk counterparts, which may potentially alter soil microbial community and elemental cycling if released into soils. In addition, we observed that dissolved organic matter (DOM) changed the interfacial process, aggregation, bioavailability, and toxicity of ENPs. The presence of DOM increased the CuO NPs uptake by and toxicity to a tested algae species. Sorption of organic contaminants by carbon nanotubes and challenges of environmental research on ENPs will be discussed. In the end, it is hoped that this presentation will demonstrate the importance of the research on the fate, transformation, and ecological responses of ENPs, therefore urging a better understanding and safe use of ENPs, i.e., sustainable development and application of nanotechnology. It is noted that a significant amount of data in this presentation are from my collaborative research with colleagues in China. I foresee that my collaboration in China will continue for many years to come.