Green or black?
Do new nanotechnologies pose a risk to our environment?
Despite the potential for nano-clean-up, one of the biggest nano-related fears is the possibility of environmental damage. Given their small size, the worry is that nanoparticles will easily become airborne and spread through the atmosphere, or will contaminate aquatic environments. Once in the environment, they could accumulate in living organisms (as many harmful substances do) or damage ecosystems.
Very little is known about the fate of nanoparticles in the environment or their impact on living systems. Some preliminary research suggests that carbon nanoparticles – buckyballs – can harm ﬁsh, but this was at very high concentrations and involved only a few ﬁsh.
The impact of nanoparticles is also going to depend on their composition and their surface chemistry. Changing the chemical groups on the outside of buckyballs makes a big difference to their properties, so it’s not easy to make generalisations.
Each type of nanoparticle behaves in a different way, making it impossible to say categorically that nanoparticles are ‘safe’ or ‘harmful’. The challenge that researchers face is that every nanoparticle has to be tested rigorously to determine their safety. This requires testing in the same conditions to ensure the results for different nanoparticles are comparable. Some scientists argue that, so far, the studies that have investigated safety have just muddied the waters.Lead image:
USDA Natural Resources Conservation Service (NRCS) CC BY