Fossil fuels smoke from

Burning fossil fuel releases carbon into the atmosphere—more than 6.3 billion tons in 1998 alone. Significant amounts of carbon also come from burning of live wood and deadwood. Such fires are often deliberately set to clear land for crops and pastures. In 1988 the smoke from fires set in the Amazon Basin covered 1,044,000 square miles. By far the most serious implication of this is the significant threat to Earth s ecosystems by global climate change. 

Particulate matter is the term used to describe solid particles and liquid droplets found in the atmosphere. Particulates are produced by a host of natural and anthropogenic sources. Mist and fog are both forms of natural particulates, as are windblown soil, dust, smoke from forest fires, and biological objects, such as bacteria, fungal spores, and pollen. The incomplete combustion of fossil fuels is one of the most important anthropogenic (human-made) sources of particulates. Such processes release unhurned carbon particles, oxides of sulfur and nitrogen, and a host of organic compounds into the air. 

Smoke. Solid particles (0.05-1.0 im) resulting from incomplete combustion of fossil fuels. 

Combustion processes. Combustion is still a major source of these substances. PCDDs and PCDFs have been found in exhaust gases from a wide variety of combustion processes - from cigarette smoke to emissions by fossil fuel power plants. Stringent controls have been introduced on waste incinerators in the UK and several other countries. It is likely now that most formerly significant sources have been controlled, leaving diffuse combustion sources, e.g. bonfires and car exhausts, as major contributors to the environmental background. 

The product of incomplete burning of various fuels (mainly fossil fuel and biomass burning) is called black carbon (BC), made up of soot and smoke aerosol that absorbs short-wave radiation. Estimates of direct RF due to BC and organic matter (OM) have led to values in the interval from +0.16 Wm-2 to +0.42 W m-2, and total absorbed radiation within 0.56 Wm 2-2 Wm-2 (the parameter BC + OM is the soot component that appears as a result of fossil fuel burning). About 10% (by mass) BC constitutes aerosol formed in biomass burning, for which RF values were obtained from 0.16Wm-2 to -0.74Wm-2, whereas the radiation absorbed by aerosol varies within 0.75 Wm-2 to 2Wm"2. 

Components of the products of biomass and fossil fuel burning responsible for radiation scattering (along with water-soluble organic and inorganic components emitted to the atmosphere as part of smoke and soot compounds) can also function as CCN. This means that emissions of BC and OM participate in the formation of indirect RF due to the impact of CCN on the formation of clouds and their properties. It follows from available estimates that such a contribution can exceed 80% with respect to total indirect RF. The BC impact can also manifest itself by local warming of the atmosphere and a decrease in cloud amount and their water content, which leads to an albedo decrease. 

Finally we note that the data which are compiled in Tables II-V are mostly based on simple laboratory tests with single specimen of typical fuel types. The applicability of these data to mass fires is debatable (Powell et al., 1979). In fact, according to Rasbash and Drysdale (1982), the effect of the environments into which the fire volatiles are released is probably more important than the nature of the combustibles. Lack of ventilation enhances smoke production, as can clearly be seen from the data of Rasbash and Pratt (1979), listed in Table II. As shown in Tables II-IV, burning of unoxidized fossil fuels and plastics yields much more... 

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. 

Chrysene occurs as a product of combustion of fossil fuels and has been detected in automobile exhaust. Chrysene has also been detected in air samples collected from a variety of regions nationally and internationally. The concentrations were dependent on proximity to nearby sources of pollution such as traffic highways and industries, and was also dependent on seasons (generally higher concentrations were noted in winter months). Chrysene has also been detected in cigarette smoke and in other kinds of soot and smoke samples (carbon black soot, wood smoke, and soot from premixed acetylene oxygen flames). It has been detected as a component in petroleum products including clarified oil, solvents, waxes, tar oil, petrolatum, creosote, coal tar, cracked petroleum residue, extracts of bituminous coal, extracts from shale, petroleum asphalts, and coal tar pitch. 

People exposed to PAHs in conjunction with particulates from tobacco smoke, fossil-fuel combustion, coal fly ash, and asbestos fibers are at increased risk of developing toxic effects, primarily cancer. Even people not susceptible to the toxic effects of PAHs may become affected when exposure occurs in conjunction with exposure to particulates (NRC 1983). This enhanced effect results from the adsorption of PAHs onto the particulates. They are vacuolized into cells, and distributed differently in tissues depending on the size and type of particulate matter. This increased PAH uptake may result in more efficient induction of AHH activity at low PAH concentrations. This activity also increases the dose to the gastrointestinal tract as a result of mucocilliary clearance (NRC 1983). This synergistic action between PAHs and particulate matter in air pollution has been associated with the occurrence of stomach cancer in humans (Fraumeni 1975). 

A 1,000-MWe power plant uses 2,000 railroad cars of coal or 10 supertankers of oil but only 12 cubic meters of natural uranium every year. Fossil fuel plants can produce thousands of tons of noxious gases, particulates, and heavy metal bearing radioactive ash along with solid hazardous waste. There are up to 500,000 tons of sulfur from coal, more than 300,000 tons from oil, and 200,000 tons from natural gas. A 1,000 MWe nuclear plant releases no noxious gases or other pollutants and much less radioactivity per capita than is encountered from airline travel, a home smoke detector, or a television set. 

The catalytic oxidation of SO. The process of catalytic oxidation can occur on the one hand on the surface of solid particles and, on the other, as mentioned above, in the liquid phase. One example is a process occurring in hot smoke produced from combustion products emitted from metallurgical works or during the combustion of fossil fuels in power plants. The SO2 conversion to SO3 can be catalysed by metallic components of fly ash suspended in smoke. The reaction occurs at a sufficient rate in the presence of ferric oxide according to the scheme ... 

Gaseous sulphur emissions coming from the refineries and their products, represent a risk for the environment (smoke and acid rain) and a health hazard. Also gas emissions containing sulphur from the combustion of fossil fuels inhibit the catalysts of exhaust systems and there is every reason to think that the level of 50 ppm fixed for 2005 for gasoline and gas oil may well only be a step towards levels closer to zero (2, 30). 

It is remarkable that basically all sub-global air pollution problems (dust and smoke, sulfur and nitrogen pollution) in connection with fossil fuel combustion have been (or can be) solved by end-of-pipe technologies. Hence, the last and apparently insoluble problem remains CO2 emissions and the subsequent increase in the greenhouse effect. CCS technology is another end-of-pipe approach and far from any sustainable chemistry. But it seems the only practical way to start the abatement of CO2 emissions. 

The hydrocarbon benzo[rz]pyrene has been found in cigarette smoke and in the exhaust from automobiles. It is also formed in the incomplete combustion of any fossil fuel. It is found on charcoal-broiled steaks and exudes from asphalt streets on a hot summer day. Benzo[rt]pyrene is so carcinogenic that one can induce skin cancers in mice with almost total certainty simply by shaving an area of the body of the mouse and applying a coating of benzo[rz] pyrene. 

Produced when a high-tempera-ture heat source, such as an open flame, comes into contact with atmospheric nitrogen. Also a by-product from the burning of fossil fuels in places such as factories, power plants, and motor vehicles. In the home the major sources of nitrogen dioxide are gas cookers, gas or kerosene heaters, open fireplaces, and cigarette smoke... 

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