Carbon Black - Uptake
Uptake via the Lung – Inhalation
Carbon black can principally be taken up through the air we breathe.more...
Carbon Black is taken up mainly via the respiratory air. Effects on health seem to increase with the age of the person inhaling the particles . Epidemiological studies have shown that high concentrations of carbon black can cause cough, sputum production, bronchitis, and even lung cancer . Also in vivo studies reveal that inhaled particles deposit in the lung and can be detected as black spots in the lung tissue . While small doses of inhaled carbon black can be found as deposits in the lung tissue without causing any damage, high doses may lead to inflammation, tissue injury or even lung tumors e.g. .
Uptake via the Skin - dermal
Nanoparticles from cosmetic or pharmaceutical products, for example suncreams, can be taken up via the skin. Carbon black has been approved for use as a color in cosmetic products (for example in mascara). So far, it has not been used in lotions for application to large areas of the skin.more...
As shown by the European project Nanoderm for titanium dioxide particles , the skin generally provides a very good barrier to nanoparticles. There has been no evidence so far of particles or nanoparticles transferred via the skin to blood vessels or close-to-surface cells of the immune system such as the dendritic cells (cells of Langerhans).
Skin cells exposed to concentrations of 10 µg particles per cm2 during in vitro studies did neither exhibit stress symptoms nor did the carbon black cause cell-damaging effects. Moreover, an in vitro test for apoptosis proved negative .
A conclusion by analogy puts it all into perspective: Tattooing ink, particularly black ink, contains carbon particles (carbon black consists of more than 96% amorphous carbon) and is deposited in the deeper layers of the skin. The fact that only very few of these particles are transported from there into the nearby lymphatic vessels while most of them remain where they are explains the lifelong durability of the tattoos.
Uptake via the Gastrointestinal Tract
Carbon black can principally be taken up by swallowing. At present, there are no studies that investigate explicitly the release of nanoscale carbon black from products during use. Carbon black has not been approved for use in food in the EU.more...
Studies of the uptake of carbon black in calves have shown that the particles are mainly taken up by the small intestines’ Peyer’s patches .
Cell cultures of large-intestine cells exposed to concentrations of 10 µg particles per cm2 did neither exhibit stress symptoms nor did the carbon black cause cell-damaging effects. Moreover, a cell culture test for apoptosis proved negative .
Uptake and risk for environmental organisms
For the larvae of the fruit fly, nanoscale carbon black administered in feed, was non-toxic, and the development and fertility of adult flies was not affected. However, particles enriched in the fly’s body and were still visible in adult animals as a distinct black coloration in the body.more...
The particle powder adhered quickly and firmly to the exterior of adult exposed animals, and removal by the natural grooming behavior was not possible. The particle-coating led to impaired mobility and killed the animals within hours by blocking the breathing holes . Such an exposure scenario to large amounts of pure carbon black is highly unlikely under real environmental conditions.
Ground-dwelling amphipods also showed an increased mortality when exposed to very high concentrations of carbon black .
A brown alga, the toothed wrack was selected as a marine model organism, and effects on fertilization, embryo development and germination in the presence of nano-and microscale carbon black has been investigated . No uptake of nanoscale carbon black was observed, but very high concentrations prevented the fertilization and development. However, germination and root growth were unaffected.
Since mussels feed by filtering smallest particles from the water, they are considered particularly at risk by expsoure to engineered nanoparticles (see picture). Carbon black strongly influenced the immuno system and certain digestive processes of animals, indicating an uptake of the particles from the water [4,5].
Soot from exhaust gases, which was not precisely defined in terms of size, reduced the toxic effect of a weed control agent to a green alga . This effect can be explained with the strong binding of chemicals to soot particles, making them unavailable for the algae and therefore no longer toxic.
In conclusion, nano-scaled, pure carbon black as a material is little toxic for the organisms studied. Harmful effects can be found, however, due to the strong binding of the soot on surfaces and chemicals.
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Canesi et al (2008) Environment International, 8, 1114-1119.
Canesi et al (2010) Aqua Tox, 100, 168-177.
- Knauer et al ( 2007) Aqua Tox, 83, 143-148.