Soot, carcinogenic compounds

In 1775, Pursevil Pott first noted that the compounds associated with soot caused scrotal cancer in British chimney sweeps (] ). Not having modern methods of Instrumental analysis available to him, Pott was unable to specify the chemical structures of these compounds. It remained until 1933 before Cook et al. identified the exact structure of benzo[a]pyrene and demonstrated its carcinogenicity ( ). Thus, polycyclic aromatic hydrocarbons (PAH) are one of the few groups of compounds which are known to be carcinogenic to man. 

IARC (International Agency for research on cancer). 1985. Polynuclear Aromatic compounds Bituminous, coal tar and derived products, shale oils and soots. Monographs on the Evaluation of the Carcinogenic Risks of Chemicals to Humans, 35 4. 

Benzo[a]pyrene, one of the most thoroughly studied carcinogens, is formed whenever organic compounds undergo incomplete combustion. For example, benzo[a]pyrene is found in chimney soot, in broiled steaks, and in cigarette smoke. Long before our... 

In 1775, PAHs were the first group of compounds known to cause cancer in humans. Nowadays, many of these compounds are well-known carcinogens in humans and animals. PAHs are produced in the environment as the result of heating organic matter to high temperatures like tobacco smoke, soot, coal tar, creosote production, wood burning, smoked foods, roasted coffee, charbroiled meat, and fossil fuel combustion exhaust. However, the major environmental source comes from asphalt, tar, used motor oil, diesel exhaust, and coal burning. 

IARC. 1985. Polynuclear aromatic compounds. Part 4, Bitumens, coal-tars and derived products, shale-oils and soots. IARC monographs on the evaluation of the carcinogenic risk of chemicals to humans. International Agency for Research on Cancer. 35 39-81. 

Carbon is a cosmic and human element. There is about 16 kg of carbon in the human body, most of it in the tissues. It is the most essential element to life. Carbon itself is non toxic, but some simple compounds (carbon monoxide and cyanide) can be very toxic. Carbon black, which is like soot, is an irritant and can harbour carcinogenic materials. 

There are an infinite number of compounds that are produced during a combustion process. Some common building materials and contents are known to give off toxic, corrosive and/or carcinogenic fumes when involved in fire. In addition to fumes, harmful particulates in the form of soot or other fallout present significant risks to the environment. 

Atmospheric oxidants or sulfur oxides oxidize PAH to compounds including quinones, which are carcinogenic. PAH vary in their sensitivity to photooxidation. For example, 60% of B[a]P in soot particles was degraded under light in 40 minutes, whereas several other PAH showed little or no photooxidation (Thomas etal., 1968). On exposure of equimolar concentrations of B[a]P and benz[a]anthracene to a simulated atmosphere of ozone and ultraviolet irradiation, more than half of B[a]P was degraded in 30 minutes compared with only 20% degradation of benz[a]anthracene. 

Wolff RK, Henderson RF, Snipes MB, Sun JD, Bond JA, Mitchell CE, Mauderly JL, McClellan RO. Lung retention of diesel soot and associated organic compounds. In Ishinishi N, Koizumi A, McClellan RO, Stober W, eds. Carcinogenic... 

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