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Nanotechnologies for Agriculture and Foods: Past and Future
Cecilia Bartolucci
National Research Council of Italy, Foresight Group, Department of Chemical Sciences and Technology of Materials, Institute of Crystallography, Via Salaria km 29.300, Rome 00015, Italy
Nanomaterials and nanoparticles are not an invention of the twentieth century. Examples of nanostructured materials can be found throughout the fourth to the seventeenth century. Important examples are vividly colored stained glass windows in European cathedrals obtained through the use of gold nanoparticles; silver or copper nanoparticles used in the Islamic world to give luster to their ceramics; and finally carbon nanotubes and cementite nanowires present in the famous Damascus saber blades. These materials, showing unusual characteristics, were generally produced empirically by talented craftsmen, often through the use of high temperature.
The intentional manipulation at atomic level or molecular scale to manufacture nanoparticles or nanostructured materials, however, requires the understanding and the control of matter at dimensions between 1 and 100 nm, approximately, and was possible only after the advent of high-powered microscopes, in particular the scanning tunneling microscope by Gerd Binning and Heinrich Rohrer in 1981, which for many marked the birth of nanotechnologies. From that moment, tools were developed that allowed imaging, measuring, modeling, and manipulating matter at nanoscale to achieve altered characteristics that could differ greatly from those on the macroscale. One should talk about nanotechnologies only if the correlation between the nanostructure of the novel materials and the resulting highly unique properties is recognized and deliberately applied. This criterion excludes naturally occurring nanoparticles and hence naturally formed biomolecules and material particles, and separates these from the particles resulting from nanotechnological applications. It is also clear from the above description of nanotechnologies that these encompass a whole group of different technologies and involve many different disciplines. Soon, several countries recognized the applicability of nanotechnologies in several different sectors such as medicine, biotechnology, electronics, materials science, energy, and more. In 2000, the US National Nanotechnology Initiative (NNI) was created to support this highly interdisciplinary technological development, while in 2009, the European Commission recognized nanotechnology as one of the six key enabling technologies [1]. Several developing countries such as India, Brazil, South Africa, Thailand, the Philippines, Chile, Argentina, and Mexico invested millions in pursuing nanotechnologies during the first decade of the twenty-first century, while in 2005, the number of nanotechnology patent applications from China ranked third, behind the United States and Japan [2].
While consumer products making use of nanotechnologies and engineered nanomaterials began appearing on the marketplace in everyday products such as cosmetics, clothing, sporting goods, and computer processors, the applications in the agriculture and food sector lagged behind. The main reason for this different development is probably due to different levels of risk/benefit factors attributed to distinct applications. In fact, while the benefits due to the use of nanotechnologies in medicine are, despite possible risks, recognized as being very important by most stakeholders, including consumers, the applications of engineered nanomaterials or nanoparticles in, or around food cause alarm. In 2004, Britain's Royal Society and the Royal Academy of Engineering published a report [3] in which they illustrated not only the opportunities provided by nanotechnologies but also the necessity for an open debate and the need to address uncertainties about the health and environmental effects of nanoparticles. They also recommended the evaluation of nanospecific regulations. In 2011, the European Commission published a “Recommendation on the definition of nanomaterials,” which uses size as the only defining property of the material (i.e., size range 1–100 nm) [4]. Regulations on food information followed soon afterwards [5], requiring indication of nanomaterials in the list of ingredients. Specifically, the ingredients to be labeled “XX (nano)” are “engineered nanomaterials,” further characterized as “any intentionally produced material,” with size on the order of 100 nm, or above, retaining “properties that are characteristics of the nanoscale.” These characteristics are related to the large specific surface area, and/or physicochemical properties different from those of the nonnanoform of the same material [5]. The discrepancies between the recommendation and the regulation underline the regulatory uncertainties regarding nanolabelling, uncertainties which still exist also outside the European Union.
In the past years, there have been great national and international efforts in developing risk assessment and risk management approaches that propose and implement strategies to identify potential hazards. Today, the need for a differentiated debate involving all actors is becoming increasingly necessary. For years, the word “nano” has been used as an advertising tool by both supporters and detractors of nanotechnologies. The former used it to underline unprecedented, possibly all-resolving characteristics; the latter as an overall warning sign. In particular, in the public perception, anything “nano” applied to agriculture and food runs counter-current to the trends on “organic,” “natural,” and “environment-friendly.” A study conducted in 2012 [6] showed that while there was an increased effort in addressing the complexity of the “nano issue” among the experts community (both scientists, policy makers, and regulatory bodies), the results were communicated insufficiently, the processes were less transparent, and the industries remained, or became silent. As a consequence, the knowledge among consumers regarding nanotechnologies and the benefits of their applications decreased, while uncertainty and expectation of the risks to health and environment increased significantly. It has been shown [7] that communication of scientific uncertainty for a given risk will give rise to a di...
