In the study, the researchers used several different techniques to analyze the lung fluids from 64 asthmatic kids living in Paris (chosen because they had already undergone the invasive process of removing lung fluids, which would be arduous for healthy patients). Man-made carbon nanotubes were found in each sample, which caused the researchers to conclude that humans are constantly breathing them in. Using several different analytic techniques on five of the samples, the researchers also found carbon nanotubes inside macrophages, immune cells that work within tissues to combat pathogens. The researchers suspect that the carbon nanotubes originate in vehicle exhaust, and they found similar structures in the dust and exhaust that they tested. But it’s not clear if that’s the only source of the carbon nanotubes. And though there’s evidence that prolonged exposure to carbon nanotubes can have asbestos-like effects on the lungs, causing inflammation and lesions that can turn into cancer, the researchers aren’t sure that the shape and length of the carbon nanotubes found in vehicle exhaust can cause that kind of damage. Importantly, the researchers have discovered and documented an effective way to look closely at carbon nanotubes in tissue samples. Their hope, they write, is that this methodology will lead to new findings about the health effects of carbon nanotubes in the lungs.
