Thursday, 1 October 2015


Carbon and its components are widely distributed in nature. The estimation is that carbon forms 0,032% of The Earth’s crust. Free carbon is found in big reservoirs like hard coal, amorphous form of the element with other complex compounds of carbon-hydrogen-nitrogen. Pure crystalline carbon is found in the form of graphite and diamond.
The Earth's atmosphere contains an ever-increasing concentration of carbon dioxide and carbon monoxide, form fossil fuel burning, and of methane (CH4), form paddy fields and cows.
No element is more essential to life than carbon, because only carbon forms strong single bonds to itself that are stable enough to resist chemical attack under ambient conditions. This give carbon the ability to form long chains and rings of atoms, which are the structural basis for many compounds that comprise the living cell, of which the most important is DNA.
Big quantities of carbon are found in the form of compounds. Carbon is present in the atmosphere as carbon dioxide in 0,03% in volume. Several minerals, like limestone, dolomite, gypsum and marble, contain carbonates. All the plants and live animals are formed by complex organic compounds where carbon is combined with hydrogen, oxygen, nitrogen and other elements. The remains of live plants and animals form deposits: of petroleum, asphalt and bitumen. The natural gas deposits contain compounds formed by carbon and hydrogen.

Carbon and human health.

Elemental carbon is of very low toxicity. Health hazard data presented here is based on exposures to carbon black, not elemental carbon. Chronic inhalation exposure to carbon black may result in temporary or permanent damage to lungs and heart.

Pneumoconiosist has been found in workers engaged in the production of carbon black. Skin conditions such as inflammation of the hair follicles and oral mucosal lesions have also been reported from skin exposure.

Carcinogenicity- Carbon black has been listed by the International Agency for Research on Cancer (IARC) within Group 3 (The agent is not classifiable as to its carcinogenicity to humans).
Some simple carbon compound can be very toxic, such as carbon monoxide (CO) or cyanide (CN-).
Carbon 14 is one of the radionuclide involved in atmospheric testing of nuclear weapons, which began in 1945, with a US test, and ended in 1980 with a Chinese test. It is among the long-lived radionuclide that have produced and will continue to produce increased cancers risk for decades and centuries to come. It also can cross the placenta, become organically bound in developing cells and hence endanger fetuses.
Most we eat is made up of compounds of carbon, giving a total carbon intake og 300 g/day. Digestion consists of breaking these compounds down into molecules than can be adsorbed to the wall of the stomach or intestine. There they are transported by the blood to sites where they are utilized or oxidized to release the energy they contain.

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