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NanotechnologyThe Costs
There are no known problems with nanotechnology but with increased use and exposure to humans and the environment, certain aspects of this technology make it risky. The small size and greater mobility of free nanoparticles mean they pose a greater threat than fixed nanoparticles. Health Risks Millions of people apply nanoparticles to their skin daily in sunscreens and cosmetics, but we do not know how nanoparticles behave when placed onto or taken into the body. They may be very easily absorbed into the body. They may be toxic to humans. This is referred to as nanotoxicity and poses the greatest long term threat to human health. Nanoparticles may affect the regulatory mechanisms of enzymes and other proteins. If they can move freely across the blood brain barrier and enter the brain tissue, they have the potential to cause brain damage or other central nervous system disorders. They could even interfere with human DNA. Nanoparticles could cause an ‘overload’ on phagocytes, the cells that ingest and destroy foreign matter. This is likely to trigger a stress reaction that can lead to inflammation and weaken the body’s defences against other pathogens. Environmental Risks We do not know the risks of nanoparticles to the environment as there is not enough current data to determine what effect they will have. However, exposure to high levels of aluminium nanoparticles has been found to affect the growth of some plant species. The US National Research Council has released a report entitled A Matter of Size, saying there is evidence that nanoparticles could affect the health of laboratory animals and recommending safety measures. Free nanoparticles can be accidentally released into the air or water during their production, use or as a waste product. They may accumulate in animal tissue and through the food chain pose a serious threat to any humans that consume them. The unique properties and behaviour of nanoparticles means that they become more widely dispersed when they are released into the environment. This in turn means that a wider range of organisms may be exposed to these potentially toxic materials. Given that nanoparticles are potentially highly toxic and may persist and disperse throughout the environment, the possibility that they may disrupt ecosystem functioning needs to be considered. This is because a wide range of individuals across many species may be exposed to nanoparticles as they disperse through the environment. Harm to a single species may lead to a disruption in the functioning of the whole ecosystem. Disruption of natural bacterial processes could affect the fixing of nitrogen. This is the process by which atmospheric nitrogen gas is converted into ammonia. The ammonia is subsequently available for many important biological molecules such as amino acids, proteins, vitamins, and nucleic acids. Organisms that have been altered by nanotechnology might mutate and evolve into harmful new viruses. Nanotechnology may make humans more effective at destroying the environment because stronger materials and larger machines accelerate the pace of destruction. Social Risks
Corporations will be able to control the building blocks of nature and an even bigger gap may grow between rich and poor. Massive unemployment and social breakdown may occur. Surveillance monitoring and tracking of individuals may become more common. Molecular sized microphones, cameras and surveillance devices may become widespread because they are cheaper to buy. There is clear potential for nano applications to erode our privacy and freedom. There is also the potential for far greater genetic profiling and other applications that will invade privacy. Nanotechnology may be used to extend today's weapons capabilities by miniaturising guns, explosives and electronic components of missiles, and increasing the accuracy and precision of weapons. It is also possible that armies could develop nanoparticles to attack physical structures or even biological organisms at the molecular level using such technology in a potentially lethal way. The Grey Goo Scenario If nanoparticles are created to be self replicating there is the risk of them replicating uncontrollably, multiplying like a virus and infecting everything. ‘Grey goo’ is a phrase coined to describe what the earth’s surface will become like, as a result of nanoparticles disassembling the environment. |
