Nanotechnology incorporates a wide range of nano-scale particles – around a thousand times smaller than the thickness of a human hair and, in essence, invisible to the human eye. Whilst nanoparticles exist naturally in the environment, their production has only become viable through recently developed manufacturing techniques, leading to a variety of manufactured nanoparticles that are revolutionising existing technologies and products, and producing step-changes in performance. Manufactured nanoparticles are now prevalent throughout society, in medical treatments, cosmetics, food preparations and the built environment. In the built environment, they are found in self-cleaning glass, high strength bolts and welds, self-healing paint – essentially any product that has delivered a step change in performance in the last few years.
Some manufactured nanomaterials are probably benign but there is significant research indicating that some are hazardous to health. Similarities with asbestos have been drawn by some researchers, so the potential for a negative long-term impact cannot be ignored.
With their increasing use in the built environment, and so increasing human contact, additional research is crucial to ensuring the safe and effective use of nanomaterials and in maintaining public confidence. Researchers argue that they are probably ‘safe’ when they remain bonded into the product or material, but concerns focus on if they become ‘bioavailable’ (i.e. a substance that can be absorbed by the human body) as they then have inhalation, ingestion and dermal pathways into humans.
|Some concerns relate to dosage, with a belief
that small doses are unlikely to create problems. However, there are some claims that certain particles may be problematic even at low dose levels. An additional challenge is that, as is
typical with many health concerns, the problems envisaged are likely to take many years to be obvious in individuals affected.
Despite the research suggesting health problems, most countries have stopped short of draconian measures for control of nanomaterials, perhaps being unwilling to stem the tide of beneficial innovations that have been enabled through nanotechnologies. Advice from the UK authorities is to take a prudent approach although little specific advice is provided about how to achieve this. Much of the safety research has focussed on the manufacture of products incorporating nanoparticles. The question that a Loughborough University team is asking is whether some construction, maintenance, refurbishment and demolition activities could make the nanoparticles bioavailable, and what measures should be taken to minimise any risks posed.
As nanomaterials are not listed as toxic and do not appear on lists under the Control of Substances Hazardous to Health (COSHH), there is no requirement to state their presence in products. Therefore designers, contractors and building users do not know what types of nanomaterials are incorporated in which construction products, and so they don’t know where they are.
Professor Alistair Gibb is Royal Academy of Engineering Chair at Loughborough University and Head of the European Construction Institute based at Loughborough. Alistair and his team have obtained funding from the Institute of Occupational Safety and Health (IOSH) to start addressing these challenges. The team will identify materials and products containing nanoparticles, investigate which types of nanoparticles are present, and develop tests to replicate demolition activities on the products to assess the likelihood of bioavailability of the particles during demolition processes.
The results will be cross-referenced with the developing epidemiological research as it separates the benign from the hazardous particles and will therefore be aimed at providing practical guidance for industry and end-users.