I’ve allocated this week for catching up on reports, but I’ve also spent a bit of time reading through the notes I made at BOHS Conference in Harrogate a few weeks ago.
One of the sessions I attended was devoted to nanotechnology. This is a fast developing area, although as it is generally still very much in the R & D phase, I guess most occupational hygienists haven’t had much involvement with it yet – I certainly haven’t – but as we’re likely to see more production processes coming on line in the not too distant future its important to keep abreast of developments.
The first presentation was a keynote address from John Hulme, a safety adviser at Cambridge University. A lot of research work on nanotechnology takes place at the University so he has had to work with the research scientists to ensure the risk are assessed and controlled. This isn’t easy when we’re not certain about the hazards and risks associated with nanoparticles. John gave a good overview of the state of knowledge. Some of the key points I noted were:
- over 1000 consumer products already contain nanoparticles
- nano-particles are not new – they’ve been around for a long time – there are natural sources (e.g. forest fires, wood stoves, volcanoes) and some “old” technology creates them (e.g. carbon black, traffic exhaust fume, welding fume, plastic fume)
- the small size of nanoparticles means that they can interact with DNA
- nanoparticles have a very high surface area to volume ratio and have highly reactive surfaces which can increase their toxicity
- nano-particles can pass through biological barriers (including the blood brain barrier) much easier than larger particles
- the chemical (and toxicological) properties of materials change when they are nano-sized
- as the surface area of nanoparticles is the main parameter which affects their toxicological properties, measuring their mass concentration is unlikely to be the most relevant way of evaluating he degree of risk
Professor Ken Donaldson of Edinburgh University, a leading authority on the health effects of nanoparticles provided an update on research into their effects. Up to now much of the work has focused on pulmonary effects, but there are concerns about the effects on the cardiovascular system which need to be investigated. Other key areas of research include potential effects on the brain and the foetus, the risk of chronic pulmonary obstructive disease (COPD) and asthma, and the effects caused by exposure to nano-fibres
Gary Burnett of HSL talked about the difficulties involved in measuring nanoparticles. His key points were
- what metric should be used? – mass concentration, the number of particles or the surface area
- results are confused by the background concentration of nanoparticles from natural and other sources
- even when measuring the same parameter, different instruments can give different results
Rachel Smith and Colin Webb of the Health Protection Agency presented a practical case study on the introductions of exposure controls for nanoparticles during the design and commissioning of a new research facility. They talked about some of the difficulties involved in deciding on controls when the hazards and risks are not fully understood and described the very comprehensive measures that were introduced.