Soot, carcinogenicity

A large number of polycyclic aromatic hydrocarbons are known Many have been synthesized m the laboratory and several of the others are products of com bustion Benzo[a]pyrene for example is present m tobacco smoke contaminates food cooked on barbecue grills and collects m the soot of chimneys Benzo[a]pyrene is a carcinogen (a cancer causing substance) It is converted m the liver to an epoxy diol that can induce mutations leading to the uncontrolled growth of certain cells... 

Other factors associated with the risk of NMSC include exposure to ionizing radiation and arsenic, which is connected with BCC. Chemical carcinogens that give rise to NMSC include industrial hydrocarbons that are found in coal tars, soot, asphalt, paraffin waxes, and tobacco.21 Exposure to the human papilloma virus (HPV-6, -11, -16, and -18) has been linked to SCC.31 Lastly, a personal history of previous melanoma is a risk factor for developing another primary melanoma. 

Man has served as the unintentional guinea pig for the identification of some major classes of carcinogens. These include the polycyclic aromatic hydrocarbons (PAH), or polyarenes, which have been identified as the active components of soot, which was recognized by the London surgeon Percivall Pott two centuries ago as responsible for cancer of the scrotum in chimney sweeps. Subsequently, polycyclic hydrocarbons have been implicated as agents responsible for skin cancer in other occupations such as shale oil distillation and mule spinning in the cotton industry. 

Although various restrictions have been placed on carbon particulate emissions from different types of power plants, these particles can play a beneficial, as well as a detrimental, role in the overall plant process. The detrimental effects are well known. The presence of particulates in gas turbines can severely affect the lifetime of the blades soot particulates in diesel engines absorb carcinogenic materials, thereby posing a health hazard. It... 

In the 1930s, polycyclic aromatic hydrocarbon was isolated from coal tar and demonstrated to be carcinogenic. Despite this evidence, millions of people continue to expose themselves to the soot from tobacco and suffer from the resulting lung cancer. 

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. 

Initially, major attention was focused on emissions of diesel soot from light- and heavy-duty motor vehicles, because the particle extracts contained such direct-acting bacterial mutagens and animal and possible human carcinogens (IARC Group 2B, 1989) as 1-nitropyrene (1-N02-PY) and the 1,6- and 1,8-dinitropyrenes (DNP), as well as a third isomer, 1,3-dinitropyrene, IARC Group III. For example, Paputa-Peck and coworkers (Paputa-Peck et al., 1983 IARC, 1989) reported 100 nitro-PAHs (17 positively identified) in... 

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... 

Although various restrictions have been placed on carbon particulate emissions from different types of power plants, these particles can play a beneficial, as well as a detrimental, role in the overall plant process. The detrimental effects are well known. The presence of particulates in gas turbines can severely affect the lifetime of the blades soot particulates in diesel engines absorb carcinogenic materials, thereby posing a health hazard. It has even been postulated that, after a nuclear blast, the subsequent fires would create enormous amounts of soot whose dispersal into the atmosphere would absorb enough of the sun s radiation to create a nuclear winter on Earth. Nevertheless, particulates can be useful. In many industrial furnaces, for example, the presence of carbon particulates increases the radiative power of the flame, and thus can increase appreciably the heat transfer rates. 

In England in 1775, Dr. Percivall Pott wrote a paper on the high incidence of scrotal cancer in chimney sweeps who were typically boys small enough to fit inside chimneys and clean out the soot. Pott suggested that chimney soot contained carcinogens that could cause the growth of the warts seen in scrotal cancer. Over a 150 years later, chimney soot was found to contain hydrocarbons capable of mutating DNA. 

The first known carcinogen was an aromatic substance discovered around the turn of the twentieth century in chimney soot. Chimney sweeps in Great... 

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. 

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