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.
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.
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).
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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