A study into the health risks posed by nanofibres has quantified the lengths at which they are harmful to the lungs.
Nanofibres – tiny fibres used in the manufacturing of a range of products, from tennis rackets to airplane wings – can be made from a range of materials, including carbon. They are about 1000 times smaller than the width of a human hair and can enter the lung cavity when inhaled. There has been growing concern that nanofibres may cause similar health problems to asbestos.
Researchers from the University of Edinburgh prepared silver-nanofibres of five defined length classes to examine the threshold for acute pleural inflammation in the lungs. Nickel-nanofibres and carbon nanotubes were used to strengthen the relationship between fibre length and pleural inflammation.
The researchers then looked at the effect of these fibres on mouse cells. Their findings showed that short fibres of a length less than five-thousandths of a millimetre did not affect lung cells.
Commenting on the findings, Ken Donaldson, professor of respiratory toxicology at the University of Edinburgh, said: “Concern has been expressed that new kinds of nanofibres being made by nanotechnology industries might pose a risk because they have a similar shape to asbestos.
“We knew that long fibres, compared with shorter fibres, could cause tumours but until now we did not know the cut-off length at which this happened. Knowing the length beyond which the tiny fibres can cause disease is important in ensuring that safe fibres are made in the future, as well as helping to understand the current risk from asbestos and other fibres.”
The research is published in the journal Toxicology Sciences.
