Nanotechnology can offer significant benefits to society. Over 600 products are known to contain nanomaterials, including sunscreens, cosmetics, food additives, paints, fuel additives, lubricants and medical implants. With the market rapidly expanding, there is the potential for nanoparticles to enter the environment through many routes and in greater quantities, which has caused some concern.
While the study found no significant evidence to suggest that nanomaterials could be a source of environmental or health hazards, past experience has shown that some products and chemicals thought to be safe have been later discovered to cause damage to the environment and human health. A key example is asbestos, a fire-retardant that was revealed to cause serious lung disease.
There are no specific regulations covering nanotechnologies in the European Union and the use and disposal of nanomaterials is governed by a number of separate regulations including REACH1, a European Community regulation on the safe use of chemicals. The authors recommend changes to REACH to specifically incorporate nanomaterials, including suitable testing protocols.
The special properties of nanomaterials arise from how the material is designed to function, and not their small size or method of production. The authors therefore advise that the function and behaviour of nanomaterials should be the basis for assessment of risks to the environment and human health.
However, safety studies examining potential risks and methods to detect nanoparticles accumulating in the environment have not kept pace with the speed of development of the new materials. This implies that regulatory bodies have insufficient information on which to base their policies and further research programmes with clear priorities should be established.
Of particular concern to the authors is the increasing use of nanosilver and carbon nanotubes. Nanosilver is an antibacterial agent incorporated into clothing. Carbon nanotubes are among the least biodegradable of man-made products and are produced in a variety of different forms with different functions, for example, to target the delivery of drugs in the body or for use in computer components.
Some laboratory tests have shown that aquatic organisms can ingest nanomaterials, and nanosilver has been shown to be toxic to bacteria and fish with implications for wider ecosystem functioning and water quality. Other studies suggest that nanoparticles could cross the blood/brain barrier. In addition, there is evidence that carbon nanotubes could act the same way as asbestos fibres and inflammatory responses to carbon nanotubes have been observed in the lungs of rats and mice.