Physicochemical and morphological characterisation of nanoparticles from photocopiers: implications for environmental health

Abstract

Several reports link printing and photocopying with genotoxicity, immunologic and respiratory diseases. Photocopiers and printers emit nanoparticles, which may be involved in these diseases. The physicochemical and morphological composition of these emitted nanoparticles, which is poorly understood and is critical for toxicological evaluations, was assessed in this study using both real-time instrumentation and analytical methods. Tests included elemental composition (40 metals), semi-volatile organics (100 compounds) and single particle analysis, using multiple high-sensitivity/resolution techniques. Identical analyses were performed on the toners and dust collected from copier's exhaust filter. Engineered nanoparticles, including titanium dioxide, iron oxide and fumed silica, and several metals were found in toners and airborne nanoscale fraction. Chemical composition of airborne nanoscale fraction was complex and reflected toner chemistry. These findings are important in understanding the origin and toxicology of such nanoparticles. Further investigation of their chemistry, larger scale exposure studies and thorough toxicological characterisation of emitted nanoparticles is needed.

Keywords::

• Nanoparticles
• printers
• photocopiers
• toner
• environmental health
• nanotoxicology

Acknowledgement

Authors would like to thank the photocopy centre employees for their help and support, as well as Dr. Earl Ada of the UML Materials Characterization Laboratory and Prof. Daniel Schmidt for their assistance with morphological analysis of toners and nanoparticles. This study was supported in part by the Nanoscale Science and Engineering Centers Program of the National Science Foundation (Award #NSF-0425826) NSF center Grants and the Center for Nanotechnology and Nanotoxicology at the Harvard School of Public Health.