ScienceDaily (June 11, 2012)

Environmental pollution including carbon particles emitted by car exhaust, smoking and long term inhalation of dust of various origins have been recognized as risk factors causing chronic inflammation of the lungs. The link between smoking and autoimmune diseases such as rheumatoid arthritis has also been established. The Nanomedicine and Molecular Imaging team at Trinity College Dublin's School of Medicine led by Dr. Y.Volkov investigated similar risks caused by nanotechnology products which if not handled appropriately may contribute to the generation of new types of airborne pollutants causing risks to global health. The findings that have been recently published in the international journal Nanomedicine .

The scientists applied a wide range of nanomaterials including ultrafine carbon black, carbon nanotubes and silicon dioxide particles of different sizes, ranging from 20 to 400 nanometers, to human cells derived from the lining of the airway passages, and to the cells of so-called phagocytic origin. The nanoparticles cause specific transformation of the amino acid arginine into the molecule called citrulline which can lead to the development of autoimmune conditions such as rheumatoid arthritis. In the transformation to citrulline, human proteins which incorporate this modified amino acid as building blocks, can no longer function properly and are subject to destruction and elimination by the bodily defense system.

For more details and source: http://www.sciencedaily.com/releases/2012/06/120611105311.htm