There’s a new kid on the block that’s rivalling asbestos in terms of the dangers when inhaled. A University of Edinburgh study discovered that carbon nanotubes are dangerous when they get into the lungs, forming scar-like tissue that the body uses as a type of scaffolding, building new cells over them, so thickening the walls of the lungs.
Carbon nanotubes are made from sheets of graphite that are no thicker than an atom (about a nanometer) and they’re formed into cylinder of varying diameter. Scientists have noted the similarities between carbon nanotubes and asbestos for several years and warning of the potential health and environmental risks. Carbon nanotubes are excellent electricity conductors and can also be used to reinforce polymers, creating very strong plastics.
Nano technology is the technology of the future, so carbon nanotubes are set to play an important role in the future of manufacturing – computer chips, energy efficient batteries, electronics, even in new drugs.
An exciting discovery in nanotube research is that they can emit light and will be able to replace standard copper interconnects in circuits by optical waveguides manufactured from nanotubes which will result in fully integrated optoelectronic circuits.
The Edinburgh research specifically only looked at carbon nanotubes that emulated asbestos fibre behaviour and their potential to cause certain types of cancer. Other types of nanotubes may affect the body in different ways – either better or worse. The hypothesis used in the research was that long, thin carbon nanotubes could have the same impact as similarly shaped asbestos fibres. The study was not conducted to curtail the development of nanotubes but to highlight any potential dangers they could present at manufacturing and disposal sites.
The toxicity of carbon nanotubes is an important issue for the nanotech industry. Research is ongoing and the data are still subject to criticism and fragmentary at best. Available data clearly show that nanotubes can cross membrane barriers under some conditions, suggesting that if they reach the human organs it could result in fibrotic or inflammatory reactions. Carbon nanotubes may deposit in the alveolar ducts of the lungs if they align length wise with the airways which leads researchers to postulate that they could lead to pleural mesothelioma (cancer of the lining of the lungs) or peritoneal mesothelioma (cancer of the lining of the abdomen). Both these conditions can be caused by asbestos exposure.
With business and research communities increasingly investing in carbon nanotubes for a wide range of applications under the assumption that they are no more hazardous than graphite, further research is essential to avoid long term hazards such as we’ve already seen with asbestos use. Current scientific thinking suggests that under certain conditions (especially those that involve chronic exposure), carbon nanotubes may pose a serious risk and health hazard.
Although asbestos was known to cause health problems as far back as the 1920’s, it was widely used across the globe for many years and wasn’t totally banned in the UK until 1999. This has left us with a legacy of asbestos problems with more diagnoses and deaths expected, especially over the coming 10 years. It’s essential that research into carbon nanotubes is carried out promptly to prevent a similar health hazard from this new wonder material.