A recent scientific study has concluded that breathing certain types of carbon nanotubes, or microscopic carbon particles used in nanotechnology research, could produce similar symptoms to inhaling asbestos fibers. In some recorded instances, patients who inhaled these carbon particles developed the same types of lung diseases as workers who had handled asbestos insulation in years past, including mesothelioma, an aggressive form of cancer that strikes the pleural lining of the lungs.
A carbon nanotube is a sheet of graphite (the same material found in pencil “lead”) with the thickness of an atom. Scientists exploring the applications of nanotechnology use carbon nanotubes as basic building blocks for machine parts measured in nanometers (one one-billionth of a meter). Carbon nanotubes are often joined together to form sheets, or are added to different chemical compositions to change their properties.
The research that showed the link between carbon nanotubes and mesothelioma showed that long, thick nanotubes behave much like asbestos fibers when the patient inhales a sufficient amount of the substance. Similarly to the established pathology of asbestos, the carbon nanotubes would pass through the tiny air sacs in the lungs, through the lung walls and into the pleural mesothelium, the fluid lining that protects and cushions the lungs. The nanotubes would potentially affect the mesothelium at a cellular level, creating mutations and malignancies that eventually lead to mesothelioma.
Professor Kenneth Donaldson of Scotland’s University of Edinburgh led the research efforts into this new potential health hazard. He and his team injected mice with carbon nanotubes and asbestos fibers of differing lengths. When the researchers noticed much of the same pathology occurring in mice injected with long carbon nanotubes as they saw in those injected with long asbestos fibers, Professor Donaldson said, “The results were clear”.
Still, the apparent correlation between mice injected with both substances and humans inhaling them is not as clear. Professor Donaldson stated that the experiments are still missing some vital data. He said that it is still uncertain if carbon nanotubes can be carried through the air in a similar way to asbestos fibers and, if so, if the inhalation of carbon nanotubes will create the same results as breathing in long, thin asbestos fibers.
Professor Donaldson also noted that only long, thin strands of carbon nanotubes produced the pathology of mesothelioma in the injected mice. His results showed that carbon nanotubes of different shapes and thickness did not produce the same results. The conclusion he reached is that the thin strands behave like asbestos fibers in that they can make their way deep into the lungs, but are thin enough to bypass many of the organ’s natural cleaning systems.
He also stressed that the findings carry much more good news than bad for nanotechnology researchers, calling the discoveries “a wakeup call”. He said that the team’s results showed that materials created from carbon nanotubes “could be made to be safe” if they are assembled and handled safely. However, he also reiterated that the study only examined how the fibrous form of the microscopic tubes interacted to induce symptoms related to mesothelioma and that long-term inhalation of carbon nanotubes could induce other lung disorders yet to be discovered.
Sources: Science Daily, Natural News