Judges’ Queries and Presenter’s Replies

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Presentation Discussion

  • May 23, 2012 | 08:18 a.m.

    Do you think that fullerenes will pose a similar health risk? They are chemically similar to graphene and CNTs, but does their morphology make them safer?

  • Icon for: Thomas Bougher

    Thomas Bougher

    May 23, 2012 | 11:18 p.m.

    That is a very good question. Much of the concern regarding CNT is indeed because of their high aspect ratio, which has been previously shown to be more dangerous when deposited in the lungs (as with asbestos). However our work and a number of previous studies have made observations that CNTs are rarely airborne as individual tubes and are more often clumps of tubes. Without better knowledge of how a material such as C60 becomes airborne (clumped or individual) it is difficult to say if the risk is similar. Regardless you are certainly correct in assuming that the morphology will play a significant role in the inhalation risk.

  • Icon for: Mariko Walton

    Mariko Walton

    May 24, 2012 | 12:40 p.m.

    Interesting aspect to the energy issues that I don’t notice being explored much.

  • Icon for: Carol Johnson

    Carol Johnson

    May 24, 2012 | 02:05 p.m.

    You give examples of nanotechnology applications, CNT-based or otherwise, but then jump right to your study that is related to inhalation risk. What mechanisms do you think are the most critical for people to be inhaling CNTs from nanotech products? The only one I can really think of is during the manufacturing process if there is mechanical grinding of powders. Do you really think we will get exposed to CNTs in any other way? C60s are different in that they are naturally-occurring aerosols from combustion processes i.e. forest fires, which people could theoretically be exposed to.

  • Icon for: Saujan Sivaram

    Saujan Sivaram

    May 29, 2012 | 07:32 p.m.

    Hi Carol,
    You’re spot on. The largest inhalation risk is at the manufacturing stage. The end-user has little exposure risk; however, the particles may be aerosolized during breakage or failure (think exploding Li-ion batteries). These particles could be a risk depending on the aerodynamic diameter. I think it is important to note that public perception/education is critical to successful nanotechnology implementation. Although the nanomaterials may be able to boost the efficiency of energy harvesting devices such as photovoltaics, public fear of the health risks, whether warranted or not, may prevent widespread nanomaterial utilization.

  • Further posting is closed as the competition has ended.

  1. Caroline Golin
  2. http://www.igert.org/profiles/4725
  3. Graduate Student
  4. Presenter’s IGERT
  5. Georgia Institute of Technology
  1. Thomas Bougher
  2. http://www.igert.org/profiles/4828
  3. Graduate Student
  4. Presenter’s IGERT
  5. Georgia Institute of Technology
  1. Anne Mallow
  2. http://www.igert.org/profiles/4836
  3. Graduate Student
  4. Presenter’s IGERT
  5. Georgia Institute of Technology
  1. Saujan Sivaram
  2. http://www.igert.org/profiles/4832
  3. Graduate Student
  4. Presenter’s IGERT
  5. Georgia Institute of Technology

Implications for a future nano-world

In hopes of filling in some of the apparent knowledge gaps in understanding and analyzing the environmental health and safety concerns surrounding nanomaterials, our team examined a nanomaterial touted for use in advanced energy technologies, carbon nanotubes. Studies have suggested that the inhalation of carbon nanotubes may pose a health risk. Many studies have likened the health effects, such as inflammation and lung lesions, to that of asbestos. To assess the potential health effects associated with carbon nanomaterials we conducted a series of experiments to characterize common exposure mechanisms in terms of airborne nanotubes. In these experiments we measured exposure levels in terms of number concentration (part./cm³) and mass concentration (mg/m³) for vertically aligned carbon nanotubes and dispersed single and multi-walled carbon nanotubes. From our study we concluded that carbon nanotubes may pose an inhalation risk to people in a manufacturing or laboratory setting. We find that more work needs to be done to understand the risk and develop test processes that can be used to understand any nanomaterial inhalation risk. Additionally we believe new exposure levels need to be set for nanomaterials to secure a safe working environment and ensure that the next generation of clean energy does not reduce levels of greenhouse gas emissions at the expense of workers’ health.