Nanoparticles emitted by printers show evidence of carcinogenic status.
Researchers at Harvard University have discovered that particles with a higher carcinogenic potential than previously thought are being created and emitted during the printing process; compounds in the printer toners are interacting with each other due to the high temperatures, and releasing such nanoparticles into the air.
The study, led by Philip Demokritou, is the first to observe the transformations that take place during the printing process. Laser printers, popular in both home and office environments, use toners containing catalytically active nanoparticles, which are released into the air during printing. Once airborne, the nanoparticles can react with volatile organic compounds, thus forming compounds which potentially both carcinogenic and mutagenic; when inhaled, these compounds can accumulate in the lungs.
Demokritou and his team have been studying the health implications of nanomaterials in printer toners for five years. They conducted both in vitro and in vivo studies, in order to assess the specific toxicological effects of the nanoparticles in animals. The team discovered that, on account of their size, it is possible for the particles to enter the lungs, and even the bloodstream. These high molecular weight species could there pose a significant health risk.
“Assessing the nano-risk early on during product development, while there is still a window to apply ‘safer-by-design’ approaches, can maximise the benefits of using nanoscale materials, while minimising the potential health implications,” said Demokritou, who is now involved in a partnership between Harvard and Nanyang Technological University, Singapore. This partnership will analyse biological samples from humans in photocopying centres, with the aim of developing a deeper understanding of the effects of prolonged exposure to these nanomaterials.
The University of California’s Vicky Grassian, an expert in nanoscience and its health and environmental implications, believes it is important to understand nanotechnology, so that we can benefit from nanoparticles’ unique properties, whilst still using the technology sustainably. She says: “As a scientist, I always want to know more about what is going on in terms of nanoparticle and organic compound emissions, to see under what situations we can try and prevent these things from happening.”