Archive: Exposure to carbon nanotubes – A risk for dockyard workers and boat owners?
Since several years antifouling paints containing carbon nanotubes which shall enhance the fouling prevention are available on the market. If applied by air less spraying or removed by sanding, carbon nanotubes can be released into the air. Workers in dockyards and boat owners should be aware of the exposure risks. An increasing body of literature has been published which show carbon nanotubes exposure can pose a risk which has not yet been fully evaluated.
In a recent publication it was recorded that chronic exposure to single-walled carbon nanotubes caused malignant transformation of human lung epithelial cells. The transformed cells induced tumorigenesis in mice and exhibit an apoptosis resistant phenotype characteristic of cancer cells. This study provides new evidence for carbon nanotube-induced carcinogenesis (Wang et al. 2011). Since years several studies revealed a variety of pathogenic effects. The concern about worker exposure including amateur use to carbon nanotubes (CNT) or carbon nano fibers (CNF) arises from results of animal studies. Several studies in rodents and rats have shown:
An equal or greater potency of CNT compared to other inhaled particles known to be hazardous to exposed workers (ultrafine carbon black, crystalline silica, and asbestos) in causing adverse lung effects including pulmonary inflammation and fibrosis.
The early onset and persistence of pulmonary fibrosis observed in CNT-exposed animals in short-term and subchronic studies.
The reduced lung clearance in rats exposed to low mass concentrations of CNT. In addition, the long and thin structure of some CNT and CNF dimensionally resemble asbestos fibers, and multi-walled carbon nanotubes (MWCNT) have been observed to migrate from pulmonary alveoli to the pleura. The US-National Institute for Occupational Safety and Health stated in a recent draft which is under discussion that though additional research is needed to further elucidate the mechanisms of biological responses to CNT and CNF, these findings of adverse respiratory effects in animals indicate the need for precautionary measures to limit the risk of occupational lung diseases in workers with potential exposure to CNT and CNF (www.cdc.gov/niosh.).
WANG, L., S. LUANPITPONG, V. CASTRANOVA, W. TSE, Y. LU, V. PONGRAKHANANON & Y. ROJANASKUL (2011). Carbon nanotubes induce malignant transformation and tumorigenesis of human lung epithelial cells. Nano letters 11(7), 2796-2803.