To date there are no epidemiological studies on carbon nanotubes (CNTs) available.
Carbon nanotubes (CNTs) consist exclusively of carbon, an element present in all living beings and the air. This fact complicates the detection of the CNTs in the environment. There is currently no information on the actual existing amounts of carbon nanotubes in the environment and their distribution in the individual compartments (e.g. water, soil.
Although numerous in vitro studies on the effect of carbon nanotubes (CNTs) have been performed so far, a final statement about their toxicity is not possible due to the very controversial discussion about the observed effects in the literature. A frequently mentioned reason for this is the contamination of the materials and not the carbon nanotubes themselves.
Animal tests (in vivo) have shown that carbon nanotubes (CNTs) can be found in different organs and cell types depending on their composition and method of administration (carbon nanotubes - uptake). Due to the manifold differences of applied nanomaterials, exposure pathways and analytical methods there emerges no clear picture on how carbon nanotubes behave once inside the body.