Nanotechnology makes use of materials (natural and man-made) smaller than 100nanometers (nm). For scale, that includes materials and devices the size of individual atoms and molecules, and as small as the structural elements in cells. A human red blood cell is giant in comparison at 300mn. One sheet of newspaper is 100,000 nanometers thick!
Nanomedicine, the application of nanotechnology to medicine and heath care, shows potential for dramatic changes in the ways we diagnose and treat disease. Nanomedicine may provide us with new ways of administering and delivering medications and other treatments directly to specific targets. It will certainly provide us with new testing and imaging techniques to improve accuracy in diagnosing disease. It may even be possible to develop nano-scale surgical instruments to allow surgery at the level of a cell.
As exciting as these innovations may be, there is a lot of controversy about the use of nanomaterials in medicine as well as in other applications. Often raised are questions about the safety of the use of these materials. How will they react in the human body? Is there any risk to those involved in the manufacture or use of nanomaterials? What happens when medical nanomaterials leave the body? Some of the very features of nanomaterials that make them so appealing to medical applications are also the reasons for concern about their safety for use in humans.
Much of the research into nanotechnology in the past 10 years has been focused on the environmental and health impacts. In fact, over 1300 peer-reviewed papers on nanomaterial risk were published in 2013. (Maynard). According to the National Nanotechnology Initiative, between 2005 and 2014 they will have invested $750 million in research to better understand the environmental, health and safety impacts of nanotechnology. And we are learning that some fears are well founded, some appear to be unsubstantiated.
As research into nanotechnology continues and we begin to develop practical applications for these materials, how do we weigh the concerns about safety against the potential risks? There are two commonly applied principles when evaluating emerging technologies: cost-benefit analysis and the precautionary principle.
Cost-benefit analysis compares the expected positive outcomes of a therapy, device or procedure to the financial cost and anticipated risks or negative outcomes. This method can be very helpful when the costs and benefits are fairly well established and we can say, for instance, “This therapy gives us this benefit but the financial cost is x and the anticipated risks are y. We feel that the benefit justifies the cost and anticipated risks.”
However, when the benefits and the risks are not as well established and harder to define, this type of comparison becomes much more difficult. This is particularly true when developing policies that have to balance many factors such as economic, environmental and public health impacts both long and short term. Weighing the advantages and disadvantages of environmental regulation and responses to climate change are a prime example; the complexity of the systems and their unpredictable responses make it hard to measure benefit and even cost. Nanotechnology in its current nascent state presents similar challenges.
In response to this, many people began to use a “precautionary principle” in place of standard cost-benefit analysis. This principle argues that even when cause and effect is not clearly established, if an activity carries a threat of harm to health or the environment precautionary measures (possibly even an outright ban of the activity) should be implemented at least until further evidence is found. This type of language has been commonly used many international environmental and public health policies over the past 30 years.
As Andorno and Biller-Andorno point out in In Pursuit of Nanoethics,
…this principle does not intend to provide a catalogue of predetermined solutions to the new dilemmas raised by scientific uncertainty. Since it is, in the end, no more than prudence, it only aims to provide some guiding criteria to policy makers, who retain a wide margin of interpretation of what is the most adequate response to each particular problem.(p 139)
Taking a precautionary approach to the implementation of nanotechnologies, placing a burden of proof that these novel technologies will not harm health or the environment on the developers of the technology, makes a great deal of sense in these still very early days of nanomedicine. However, we should be cautious that we do not delay or stop all advances out of fear once we have demonstrated with reasonable certainty that no significant risk is present. As information is obtained and the variables are better defined, a cost-benefit approach should be adopted. These two approaches to evaluating and minimizing risk will be most effective in protecting the environment and health when used in a complimentary fashion.
Maynard, A. D. (2014). A decade of uncertainty. Nature Nanotechnology. 9(3), 159-160. doi:10.1038/nnano.2014.43 (available at http://ieet.org/index.php/IEET/more/maynard20141119)
Environmental, Health, and Safety Issues. (n.d.) Nano.gov National Nanotechnology Initiative.
Andorno, R., Biller-Andorno, N., (2014). The Risks of Nanomedicine and the Precationary Principle. In Gordjin, B., Cutter, A.M. (eds),In Pursuit of Nanoethics (pp 131-145).New York, NY: Springer.