The Environmental Impact of Nanotechnology
The Environmental Impact of Nanotechnology
This report looks at the recent development of nanotechnology and its environmental impact by studying the beneficial applications of technology and the consequential risks posed by it on the environment and the public. Over the course of writing this report I discovered that not much scientific literature exists on the topic and that this is itself one of the series of problems faced by nanotechnology in its emergent phase.
Nanotechnology is the branch of science whose characteristic feature is that it involves working with and creating materials or structures that are measured on the nanometer scale. Until recently, nanotechnology was but a popular theme in science fiction. However, it has since expanded into a diverse and extensive field of study and research with a wide range of possible applications. Today nanotechnology has implications in a variety of fields that affect human affairs such as medicine, agriculture, engineering, materials, ethics, and law. However, as with any emerging technology, nanotechnology has set off a number of discussions on its toxicity and, hence, impact on the environment. This has led to the setting up of regulatory bodies all over the globe to supervise the research and commercial applications of nanotechnology as well as to deal with the potential risk that nanotechnology poses to our environment.
Beneficial Applications of Nanotechnology
Nonetheless, nanotechnology has proved beneficial for the sustenance of our environment in numerous ways. One such application, according to Tina Masciangioli, is the use of nanotechnology to make more efficient water purification systems. By using advanced materials for filtration nanotechnology has the potential to make a tremendous positive impact on the long-term availability and quality of water resources. It is also possible, by the use of advanced nanosensors, to detect chemical and biological contamination in the environment (including the hydrosphere) even at very minute concentrations. Moreover, there is a vast amount of ongoing research on the possibility of using nanotechnology to completely eliminate the hazardous materials that remain behind in water systems due to the chemical processes that are currently used for water purification.
For instance, nanoparticles of iron are already being used extensively for end-of-pipe management and pollution cleanup in groundwater systems. Iron is known to chemically reduce contaminants in the environment but the use of nanosized particles further enhances its reactivity. This is essentially because the nanosized particles can access difficult areas more easily. The process can be further improved by coupling iron with other metals such as palladium on the nanoscale.
Nanosized particles of zinc oxide are also used widely for the development of greener pollution treatment processes. The minute particles of zinc oxide function dually as both sensors and catalysts. First, the presence of organic pollutants is detected by looking for changes in the visible emission signals. The zinc oxide particles then oxidize the pollutants by photocatalysis and reduce them into more environmentally friendly compounds. The benefit of using nanotechnology over other methods of purification is the dual sensor functionality of the nanoparticles being used. As a consequence of this multi-functionality the net consumption of energy of the process is reduced.
Nanotechnology can also be used to develop more environmentally friendly manufacturing processes. Since manufacturing products on the nanoscale involves assembly at the atomic/molecular level, the use of nanotechnology in the process would greatly reduce the wastage of materials and, consequentially, the amount of raw materials required. Moreover, with the aid of nanotechnology pollutants and waste products can be removed or chemically purified in manufacturing plants directly at their source. Thus, simple applications of nanotechnology such as the above can have a substantial impact upon the contamination of the environment.
Another field where nanotechnology is being used to develop more efficient processes is the generation of solar energy from photo voltaic cells. The use of a new material called nanoflakes can make the whole process much more cost effective and efficient than it is today. Firstly, by the use of this technology photo voltaic cells can be made to absorb much more sunlight than traditional ones due to the large surface area of the nanoparticles used in their manufacture. According to Dr. Martin Aagesen, the use of nanoflakes can enable up to 30 percent of the total solar energy to be converted into electric energy simply due to the reduction in the distance that the energy has to travel in a modified cell. Finally, the use of nanoparticles would require lesser amount of conducting materials like silicium for the manufacturing of a single cell thereby making them a cheaper alternative to the photo voltaic cells that are currently on the market.
Nanotechnology can also be applied beneficially in the emerging sector of hydrogen fuel generation. In fact, nanotechnology can be used to play a prominent role in nearly every step of the fuel generation process. To further illustrate this point consider the generation of electricity by the catalytic electrolysis of water. By using nanoparticles on the surface of the catalytic electrodes the efficiency and speed of the process could be greatly increased. Moreover, ongoing research on porphyrin (a kind of molecule used by plants during photosynthesis) nanotubes with a coating of platinum particles predicts that it can be a valuable catalyst for the photolytic dissociation of water.
Storage of hydrogen in tankers or transporting them via pipes is not entirely practical because, firstly, there is a possibility of leakage and, secondly, hydrogen is reactive with steel. The alternative to this is using substances that absorb hydrogen easily on their surface. Materials such as nanotubes of carbon can, therefore, have a vital role in the storage and transportation of hydrogen because of the massive increase in the absorption of hydrogen gas that is possible due to their large surface areas.
Risks Posed by Nanotechnology
For a technology that has gained prominence only recently, nanotechnology has developed very rapidly. The sudden widespread application of this technology immediately raises some concern on the interaction of nanoparticles with the environment. It is known from research that nanoparticles can reach cellular and tissue locations that larger particles of the same material cannot. Nanoparticles can access various difficult locations like the mitochondria at the cellular level, the central nervous system by the olfactory and trigeminal nerve endings in the nose, and the blood. However, owing to the difference in the pharmacokinetic properties of individual nanoparticles it is difficult to predict data for one nanoparticle from another.
Recent study has shown that buckyballs, though not highly soluble in water individually, can form aggregates that are both highly soluble in water and acts as bactericides. This matter is of concern because bacteria constitute the bottom of many food chains in the environment. Buckyballs could be extremely dangerous if they entered the human food chain because they are known to have the capacity to cause oxidative damage to animal brain and liver cells. Another study conducted on rats that had their lungs instilled with carbon nanotubes showed that the nanoparticles were responsible for the appearance of unusual granulomas on the lungs in less than a month.
Although only a few nanoparticles are manufactured on the industrial scale, the emission of wastes from such industries into the air is a matter of great concern. The human body already has mechanisms in place to deal with the larger organic and inorganic particles that enter our bodies. However, the sheer size of nanoparticles allows them to enter the body across natural tissue barriers and into the cells. Their inherent small size not only makes them more mobile but also more chemically reactive due to the increase in net surface area of the particles. Moreover, engineered nanoparticles rely on various chemical coatings that impart required characteristics to the nanoparticles but these coatings are also known to have altered toxicological properties that are potentially hazardous to living beings.
Evidently, the overall impact of nanotechnology on the environment cannot be fully assessed without fully documenting and researching its effect on the ecosystem and the public. Most studies on nanoparticles exposure have dealt only with workplace scenarios. Another important area of research, however, is the study of nanotechnology’s impact on the global environment. Nanoparticles, once released into the environment, have the potential to cause a variety of adverse organic and photochemical reactions. Take, for example, cesium dioxide. The decarboxylating and polymerizing effects of cesium dioxide are put to use industrially by mixing its nanoparticles in gasoline. This process greatly improves the combustion rate of gasoline. However, studies have shown that the environmental release of cesium dioxide particles can have a sizeable impact on the environment by altering the carbon chemistry in water, soils, and other ecological systems.
One can see from the wide range of applications of nanotechnology that it can be beneficial to the environment and society in many ways. However, without sufficient research and an assessment of the potential risks that nanotechnology poses there cannot be a sustainable and safe development of the technology. For this reason a regulatory body needs to be set up that incorporates a set of rules based on data from research on the commercial and development aspects of nanotechnology. Though commercial advantages would have to be temporarily sidelined, many scholars believe that through the aid of regulations a lot of the environmental threats posed by the development of nanotechnology can be averted.
Given the rapid development of nanotechnology, there is bound to be controversy surrounding it. Just as there is a call for regulation of the technology there is a lot of resistance to the idea as well. However, the reason why most of the opposition to regulation of nanotechnology even exists is because sufficient scientific information does not exist on the subject of the risks posed by nanoparticles on the environment and, hence, any regulation on the development of nanotechnology would be hasty and, in fact, detrimental to the development of nanotechnology. However, there have been many emergent technologies in the past like genetically modified food, etc. that were successful for a short time but failed due to unexpected problems like poor risk assessment research, legal issues, and ethical dilemmas. If one is to learn any lesson from these past events it is that it’s better to be safe than to be sorry. There is certainly a need for more research on primary nanotechnological concerns such as its toxicity and impact at the systems level of the environment.
1. Masciangioli, Tina (2002). Nanotechnology for the Environment. PowerPoint Presentation. United States Environmental Protection Agency. http://www.environmentalfutures.org/Images/nanotech.ppt. 17th December 2008
2. Anon (2007) Nanoflakes Could Make PV More Efficient. RenewableEnergyWorld.com. http://www.renewableenergyworld.com/rea/news/story?id=50956. 16th December 2008.
3. Walsh, Ben (2007). Environmentally Beneficial Nanotechnologies: Barriers and Opportunities. UK, Department of Environment, Food, and Rural Affairs. http://www.nanowerk.com/nanotechnology/reports/Environmentally_Beneficial_Nanotechnologies.html. 17th December 2008.
4. Department of Environment, Food, and Rural Affairs (2007). Charecterising the Potential Risks Posed by Engineered Nanoparticles – 2nd Report. UK, Department of Environment, Food, and Rural Affairs. http://www.nanowerk.com/nanotechnology/reports/Characterising_the_Potential_Risks_posed_by_Engineered_Nanoparticles_2nd_report.html. 16th December 2008.
5. Hunt, Geoffrey and Mehta, Michael (eds) (2005) Nanotechnology: Risks, Ethics, and Law. UK, Earthscan Publications Ltd. http://www.nanowerk.com/nanotechnology/reports/Characterising_the_Potential_Risks_posed_by_Engineered_Nanoparticles_2nd_report.html. 16th December 2008.
6. Guzmàn, Katherine, et al. (2006) Environmental Risks of Nanotechnology: National Nanotechnology Initiative Funding, 2000-2004. Environmental Science & Technology. http://www.innovationsgesellschaft.ch/images/fremde_publikationen/environmentalrisks.pdf. 16th December 2008.
Murphy, Cynthia (2004) Nanotechnology and the Environment: Beauty and the Beast? Unpublished presentation, University of Texas. http://www.utexas.edu/research/ceer/greenmaterial/Lectures/Nanotechnology%20and%20the%20Environment.pdf. 17th December 2008.
The Royal Society and The Royal Academy of Engineering (2004) Nanoscience and Nanotechnology: Opportunities and Uncertainties. Cardiff, Clyvedon Press. http://www.nanotec.org.uk/report/Nano%20report%202004%20fin.pdf. 17th December 2008.
 Author of “Nanotechnology for the Environment”, a presentation for the United States Environmental Protection Agency.
 As quoted in the article “Nanoflakes Could Make PV More Efficient” on RenewableEnergyWorld.com.
 From “Environmentally Beneficial Nanotechnologies: Barriers and Opportunities” by Ben Walsh.
 From “Charecterising the Potential Risks Posed by Engineered Nanoparticles – 2nd Report” by the UK’s Department of Environment, Food, and Rural Affairs.
 From “Nanotechnology: Risks, Ethics, and Law” edited by Geoffrey Hunt and Michael Mehta.
 From “Environmental Risks of Nanotechnology: National Nanotechnology Initiative Funding, 2000-2004” by Katherine Guzmàn, et al.