Inhaled carbon black nanoparticles create a double source of inflammation in the lungs, according to research conducted by researchers at the University of Iowa, United States. The researchers said they expected to find one level of inflammation when cells were exposed to carbon black nanoparticles, but were surprised to find that the nanoparticles activated a special inflammatory process that killed cells in a way that further increased inflammation. The surprising results came when the team discovered that the intake of carbon black nanoparticles, from sources such as diesel fuel or printer ink, killed macrophages – immune cells responsible for cleaning up and attacking infections – in a way that increases inflammation. Martha Monick, Ph.D., a professor of internal medicine and lead author of the paper, said, “Apoptosis is one way cells die in which all the contents stay in the cell, the cell just keeps shrinking onto itself and the surrounding tissue is protected. We thought that was what was happening with the carbon nanoparticles; we were wrong. A different process called pyroptosis was occurring, causing the cells to burst and spill their contents,” which, she added, can cause a secondary inflammatory response. Monick said the doses of carbon black nanoparticles used in the study were much more concentrated than typical exposure amounts. “This doesn’t mean that walking through a cloud of diesel exhaust will hurt your lungs,” she said. “It does show that we may have an environmental exposure that could contribute to inflammation in the lung.”
http://news-releases.uiowa.edu/2011/may/051811carbon-black-inflammation.html