Will Carbon Nanotubes be the Next Asbestos?
Multi-walled carbon nanotubes are one type of engineered nanomaterials currently being used in a variety of applications from composite building materials (such as decking ‘lumber’) to the building of airplanes (Boeing 787). New applications for carbon fibers are being developed every year and at the present time the United States, Japan and Western Europe lead the world in producing these fibers.
As carbon fibers are produced, and again as they are used in the manufacturing of new products, there is concern with the health effects on workers who inhale the tiny fibers/dust. Research by the National Institute of Occupational Health and Safety (NIOSH) points to a long-standing concern of mine that the new nanotube ‘craze’ may well be the asbestos ‘problem’ of the future!
Studies conducted on laboratory mice show nanotubes ‘sticking right through the lining’ of the lung, having migrated through the alveoli to the pleura, there is evidence that some of these needle-like tubes (fibers) have physically penetrated the lung lining into the region where asbestos-related mesothelioma can and has developed in workers exposed to asbestos fibers. Other studies show mice with respiratory irregularities and inflammation. Two recent reports, one from the United Kingdom (Poland et al., Nature Nanotechnology, 20 May 2008) and one from Japan (Takagi et al., J Toxicol Sci 33:105-116, 2008) contribute to the carbon nanotube/asbestos fiber comparison debate.
The recently published British study adds to the body of work showing an asbestos-like response to the carbon fibers, and after the publication of the Japanese study, the Japanese Ministry of Health, Labor and Welfare issued a notice instructing those involved in the manufacture, repair and inspection of nanomaterials, to ensure that their facilities’ processes follow strict safety measures using either sealed, unattended or automated conditions, or installing local exhaust systems.
While it is still early to state definitively, the initial results don’t look good. In fact, these studies are compelling enough to suggest action be taken to do further studies and consider more rigid safety requirements be put in place to avoid a repeat of the asbestos tragedy. RGA Environmental offers consulting services including, but not limited to working with companies to establish safe work practices, write or update health and safety plans and use air monitoring and fiber analysis techniques to determine the levels of fibers that may be present for potential worker exposure. For more information please contact your local RGA office.
Ethel Kaufman, Trainer – Seattle, WA
Tags: air monitoring, asbestos fibers, carbon fibers, dust monitoring, fiber analysis, health and safety plans, HSPs, mesothelioma, nanomaterials, Nanotubes, TEM analysis, worker exposure, worker health, worker protection, worker safety