Nanomaterials are used in a wide variety of consumer products, including electronics, cosmetics, food storage, and automotive products. Recent scholarship has highlighted its potential for advancement in many areas, including energy storage and drug delivery. However, the potential deleterious effects of nanoparticles on human health and the environment have received substantial attention among scientists and regulators. And since public opinion plays a role in policymaking, the public should be aware of the risks and adverse consequences of nanomaterials.

Historically, there has been a trend of differential risk perception between scientists and the public. Scientists tend to be more optimistic about emerging technologies and perceive more benefits and fewer risks compared to lay audiences. However, in the case of nanotechnology, risk perception has been found to be greater among scientists compared to the public, specifically with respect to areas such as pollution and health [1]; comparisons of opinion surveys between the public and scientists show that lay audiences are less concerned about such risks. In fact, the public is relatively unafraid of nanotechnology, perceiving it as less risky than air pollution or even stress [2]. However, there has been no exploration of whether lower perception of environment, health, and safety (EHS) risks is reflected in popular discourse.

As a start, we explored discussions of nanotechnology on Twitter using automated opinion mining software provided by the social media monitoring company, Crimson Hexagon. The software, ForSight, collected and tracked linguistic patterns in tweets using algorithms between September 1, 2010 and February 28, 2013. These linguistic patterns are representative of various underlying concepts, which are identified by human coders. We trained the software to recognize posts that discussed nanotechnology in the context of several topics: business, national security, environment, health, and safety (EHS) issues, medicine and/or health, energy, basic research, and consumer products.

The internet and social media are important sources of scientific information for the general public. Twitter, in particular, is an ideal medium for the distribution of information and the ability for real-time interaction among lay audiences, scientists, and other elite audiences worldwide makes it a unique platform for studies of popular discourse. The microblogging platform allows users to “tweet” snippets of text to their followers in 140 characters or less. These messages can be “re-tweeted” by other users allowing information to be widely disseminated in a short period of time. In the case of public discussion about nanotechnology, tweets and re-tweets can be powerful indicators of topics that resonate with and are most visible to Twitter users.

Although public opinion and opinions expressed on Twitter do not always coincide, it is reasonable to assume that Twitter users are more likely to be early adopters of technology who are more likely to be informed about scientific and technological innovations. If such members of the public are unaware of the EHS risks of nanotechnology, it is highly unlikely that other relatively less “tech-savvy” audiences will be.

In our analysis, we identified a total of 2,597,620 nanotechnology-related posts. Over 30 months, posts about national security made up the largest proportion of all relevant data (23.3% on average) while EHS-related content comprised the lowest proportion (9.7% on average; see figure). One potential reason for the large proportion of posts about national security is the portrayal of nanotechnology in the popular press. The media has played a significant role in disseminating information about nanotechnology and has been particularly focused on its use in weaponry and other security contexts. Early popular accounts such as the 1984 book Engines of Creation, in which the term “grey goo” first appeared, may have contributed to some of the modern discourse surrounding the technology. More recently, the potential risks posed by Drexler's “grey goo” scenario were further explored by Michael Crichton in his 2002 novel, Prey. Accounts of nanotechnology in weaponry have also surfaced in films. For example, G.I. Joe: The Rise of Cobra, which was released in the U.S. in 2009, featured a villain who used nanobots to demolish cities.

Disconnected discourses

EHS and medicine/health were the least discussed topics on Twitter. Regarding nanotechnology in medicine, this is unsurprising. There are relatively few nanotechnology-enabled medical products currently on the market; most of which are targeted drug delivery systems. Unlike widely advertised consumer products, individuals who are not in need of medical nanotechnology are likely unaware of such products. Similarly, the low volume of discussion about EHS may also reflect a lack of awareness, which can be attributed to two related trends in the media coverage of nanotechnology. First, media coverage has framed nanotechnology in a positive light, emphasizing its usefulness and economic potential [3]. Second, although coverage of nanotechnology risks increased between 1999 and 2008 [4], recent work suggests that there are relatively few such articles in the media [5]. It is therefore foreseeable that discussions about nanotechnology, even among a relatively more “tech-savvy” sample of the population, are lacking in EHS issues.

It is worth noting that Twitter discourse does not purely consist of tweets from lay users. Scientists and other societal elites also use the microblogging platform for a variety of purposes. Unfortunately, our data do not allow us to differentiate between expert and non-expert users. We are confident, however, that there are fewer experts relative to non-experts using the microblogging platform to access information about nanotechnology. However, we recognize that scientists have the ability to influence popular discourse on platforms such as Twitter. Specifically, scientists tweeting about new research on EHS issues in nanotechnology may influence popular discussions and may even be advantageous for scholars [6].

The implications of this finding for nanotechnology policy are a potential cause for concern. Public policy requires some amount of public input, and if lay the public does not perceive nanotechnology to be risky and are largely unaware of its risks, public input in regulatory policies has the potential to be uninformed. Along these lines, it seems reasonable to think that more discussion about the risks of nanotechnology among the public is warranted.


This material is based upon work supported by a grant from the National Science Foundation to the UW-Madison Nanoscale Science and Engineering Center in Templated Synthesis and Assembly at the Nanoscale (Grant no. SES-DMR-0832760). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Further reading

[1] D.A. Scheufele et al.; Nat. Nanotechnol., 2 (12) (2007), pp. 732–734

[2] D.M. Berube et al.; J. Nanopart. Res., 13 (8) (2011), pp. 3089–3099

[3] B.V. Lewenstein, J. Gorss, J. Radin; Paper Presented at the Annual Conference of the International Communication Association, New York, NY (2005)

[4] D.A. Weaver, E. Lively, B. Bimber; Sci. Commun., 31 (2) (2009), pp. 139-166

[5] S.M. Friedman, B.P. Egolf; Risk Anal., 31 (11) (2011), pp. 1701–1717

[6] S.K. Yeo, D. Brossard, D.A. Scheufele, P. Nealey, E.A. Corley; 'Tweeting to the top' The Scientist (2013) Retrieved from

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DOI: 10.1016/j.mattod.2014.01.002