Wednesday, May 21, 2008

ON ASBESTOS AND NANOTUBES

Science is objective. Using methodologies that are beyond reproach due to verification, science is clad under a mantle of facts and data. Or is it just “Emperor’s Clothes”?

Science and technology are rhetorical phenomena comparable to political and public address. It’s simply a matter of degree.

When a scientific research article is written, the authors select from the available means of persuasion to craft their language and their claims. Often, they speak to many audiences other than their peers, and when speaking to the media and the public nothing speaks more loudly than strong imagery and rhetorical tropes.

We recently observed just such an occasion. The team from the PCOST (Public Communication of Science and Technology) Project at NCSU put their heads together and is offering this preliminary assessment of the debate “On Asbestos and Nanotubes.” Their collective heads are: Christopher Cummings, Grant Gardner, Kelly Norris, Nick Temple and yours truly—and what a team of doctoral students!

In the Poland et al. (2008) study the researchers are attempting to test whether long straight multi-walled carbon nanotubes (MWCNTs) induce similar early symptoms of mesothelioma to those caused by asbestos fibers. In examining any research study it is important to separate what the quantitative data is actually showing from the authors conjecture or discussion of implications. That is not to say interpreting and expounding scientific data is intrinsically fallacious, but the differences in validity of these assertions must be made clear. For the Poland study, readers must also temper their consideration of the power of the results by noting the relatively small sample size. The following is a brief discussion of interpretive pit-falls to be wary of prior to examining reports of this study.

Although the article relates carbon nanotube (CNT) exposure risks to airborne asbestos, the researchers make no claims as to how easily carbon nanotubes (CNTs) become airborne. In fact, most CNT-manufactured products are likely safe, as they are embedded in structures. The largest concern for airborne particulate CNTs would be in factories manufacturing these products. For the sake of argument if we were to ignore this assumption, if individuals were to be exposed to particulate CNTs, it is unknown how easily they can become lodged in lung tissue. Additionally, uncertainty surrounds how readily they would migrate to the mesothelium. The Poland study bypasses these questions by installing CNTs directly into tissue to examine their effect. It is important to note that the study tissue was not lung mesothelium, but closely-related abdominal peritoneum. In addition, another question is whether CNTs can remain anchored in the tissue and in a concentration significant enough in dosage to cause mesotheliomas. What the study can claim is that asbestos and CNT particles that are long and fibrous tend to induce pre-mesothelioma symptoms when directly injected into mesolthelial tissue layers. For more detail on the science, see the ICON Backgrounder at http://icon.rice.edu/resources.cfm?doc_id=12299.

A word that to most connotes deadly carcinomas and mesothelioma, asbestos can hardly enter a headline without raising concern in readers. However, the media inevitably have to make the comparison between multi-walled carbon nanotubes (MWCNT) the highlight of their stories since this is how the experimental studies were designed. In addition, the media simply gets giddy when offered such a tantalizing headline.

One of the main purposes of the recent studies published in the Journal of Toxicological Sciences (Takagi et al., 1008) and Nature Nanotechnology (Poland et al., 1008) was to determine if mesothelial exposure (in mice) to the needle-like fibre shape of MWCNTs results in pathogenic behavior. The other main purpose, even more heavily marketed by researchers, was to determine if the pathogenic behavior of the MWCNTs was similar to asbestos fibres. This effort to compare the two is interesting since recommendations from the findings would be the same regardless of the comparison. If anything, by releasing the findings, demonstrating how the two are similar and then having to later make distinctions about how they are different only confuses the issue.

News regarding this study did not come from many sources the day it was released. A survey of world, national, and local print news sources revealed only thirteen highly redundant articles. In fact, four of these were the exact same articles simply reprinted in different Associated Press outlets. Other news outlets reporting this story included The New York Times, The Washington Post, and U.S. Newswire. Local reports were less common, including only a story by The Virginian Pilot out of Norfolk, VA and extremely brief three line blurb in Birmingham Evening Mail. Only one strictly web based news source, vnunet.com, ran the story.

The lack of stories may account for some of the redundancy found in the articles. However, this redundancy does set up a frame that may very likely be followed as more articles appear. One would expect the Associated Press to copy the same story to their various outlets. Since many large news outlets rely on the AP to break stories to them, rewrites of that material is also to be expected. As local news sources begin to pick the story up, they too will likely rely on the details from the original stories to guide their work. This is the way the news works.

As we have seen, however, the rhetoric of the original stories is confusing. The media have picked up on the metaphor of linking MWCNTs to asbestos. Considering that asbestos is something of a devil term in the rhetoric of industrial circles, such a metaphor has the power to be extremely powerful in the minds of a public still dealing with the aftermath its cancerous effects. The original study being cited is the one which originates the metaphor since the effects were so similar, but it is the media which carries this metaphor out and enacts its power.

To support this metaphor and discuss it, the media tend to be quoting the same two or three people. Andrew Maynard’s sound bite in which he says “This is a wakeup call for nanotechnology in general and carbon nanotubes in particular” is frequently used. One of the authors of the Poland study, Donaldson, is also frequently quoted as saying “It’s a good news story, not a bad one. It shows that carbon nanotubes and their products could be made to be safe.” Vicki Colvin was also quoted several times as saying that the benefits of nanotechnology are too powerful to ignore, but that this study emphasizes the importance of knowing how to handle it. These were the primary experts put into conversation with one another in the media and as such will logically lead the discussion of this issue as it progresses. It will be interesting to see how the public picks up the issue and what they do with it. The media has touted the metaphor of asbestos but at the same time has attempted to frame the issue as a cautionary tale in which science is on top of the issue now before it becomes a problem as opposed to when scientists dropped the ball on asbestos. However, the memory of asbestos may be too powerful to allow for public trust in anything linked to it, even if the link is primarily a metaphorical one.

Researchers say (even in their abstracts) that they are calling for further research and great caution so that long-term harm is to be avoided. However, the likely public reaction is do away with carbon nanotubes in products all-together in spite of any future research, even research touting positive findings (something we might want to test).

Also, by focusing attention on the similarities between carbon nanotubes and asbestos, less attention is paid to other interesting findings from the studies. For instance, the fact that short, tangled MWCNTs did not cause inflammation in mesothelial tissue, therefore did not suggest pathogenic behavior was not mentioned in most media articles.

Though most articles reporting the studies acknowledge that the greatest danger of exposure is to the workers involved in production of items containing carbon nanotubes and that researchers agree that there is no need to restrict the use of carbon nanotubes in products, by pushing the correlation between asbestos and MWCNTs the lay audience will certainly consider carbon nanotubes a public hazard. Even in the case of workers involved in manufacturing the particles, the articles report that precautions have already been put into place requiring workers to wear respirators. Towards the end of media articles, reporters point out that the study did not look at how likely and/or easily carbon nanotubes become airborne or whether they become lodged in the lungs if inhaled. But this consideration of dosage and exposure is now irrelevant to the public that is concerned with consequences and implications only.

As risk researchers Jenkins-Smith & Silva point out “members of the public appear to be more willing to believe risk increasing signals than risk-decreasing signals” —and pairing nanotubes with asbestos in the headline of a study or media article is definitely a “risk increasing” signal.

The articles continue to perplex as they state that on the one hand, there is minimal risk to consumers in handling products made of carbon nanotubes because the fibres are so embedded, but on the other hand, nanotubes should be subject to the same rules and regulations as asbestos.

Also puzzling, professors say they are “not alarmed” about the results of the studies but still insist products should be better labeled. They back this suggestion with the concern that, like asbestos, the nanotubes could be released later (i.e. construction workers or mechanics inhaling asbestos from concrete or automobile brake pads).

Here again, the language is confusing to the public because at the same time the articles tell people not to distress they also insist on the possibility that nanotubes are asbestos with a “coat of a different color.”

As a rhetorical strategy, telling people they are safe while at the same time making reference to a similar substance that lessened trust in industry and the government, only makes sense if the purpose is to actually heighten concerns and monger fear.

Slovic (1986) warns that merely mentioning possible adverse consequences to the public can make them appear more frightening. Therefore, the rhetorical force of mentioning the consequences of direct exposure to MWCNT while also establishing a direct association to a negatively explosive word like asbestos is enormous.

Because researchers are aware of the reactions the word asbestos triggers in the public, the actual motivation behind comparing the two substances, must be to first, attract the attention of the media and second, to position themselves as rescuers/saviors devoted to the public’s interest (unlike industries who are trying to sneak the hazardous materials into consumer products regardless of health or environmental risks).

Most often the media look for hot button issues while deconstructing academic research findings, in the case of the MWCNTs studies, the experiments were rhetorically designed so that the hot button issue was at the forefront, ensuring a lot of attention at the expense of some of the intricate findings and opportunity for a critical public.

The problem with this rhetorical approach is that the adverse reactions it could instill in the public could be more problematic than the media attention it draws.

No comments: