Pollution sources combustion

AhR-mediated activity results Dioxin-like activity is a useful marker of compounds that are able to activate the AhR receptor, which had been shown to be involved in numerous health effects such as impairment of immunity and nervous system or reproduction (Mukeijee 1998). There have been several studies describing AhR-mediated effects of the PMi (Wenger et al. 2009) and PMio (Clemons et al. 1998 Ciganek et al. 2004 Brown et al. 2005) aerosol size fractions. The TEQ calculated from the data of 28 PAHs (25 parent PAHs, retene, biphenyl and triphenylene) represents by average 7.5 and 95% of the dioxin-like activity associated with the particulate and gaseous fractions, respectively. Most of the activity could be produced by dioxins and furans, but also by partly oxygenated PAHs, such as polycyclic aromatic ketones and quinones that were also shown to activate AhR and to be produced by combustion pollution sources (Misaki et al. 2007). The results, furthermore, confirm that a significant portion of the AhR-mediated activity was produced by compounds present in the gas-phase at many polluted localities as it have been shown previously (Klein et al. 2006 Novak et al. 2009). 

The most widespread and persistent urban pollution problem is ozone. The causes of this and the lesser problem of CO and PMjq pollution in our urban areas are largely due to the diversity and number of urban air pollution sources. One component of urban smog, hydrocarbons, comes from automobile emissions, petroleum refineries, chemical plants, dry cleaners, gasoline stations, house painting, and printing shops. Another key component, nitrogen oxides, comes from the combustion of fuel for transportation, utilities, and industries. 

Schauer, J.J., Kleeman, M.J., Cass, G.R., and Simoneit, B.R.T. Measurement of emissions from air pollution sources. 3. C1-C29 organic compounds from fireplace combustion of wood, Environ. Scl Technol, 35 (9) 1716-1728, 2001. 

Possible pollution sources in the area include dust, ash, scum, slag, carbon coke residues, minerals, heavy oils, hydrocarbons, and combustion residues. The minerals used to produce cast iron and steel were imported mainly from Africa (Liberia and Mauritania), Canada, India, the former USSR, and from the American Continent (L Industria Mineraria, 1979a). 

A calculation of maximum/minimum ratio from the atmospheric input data in Figure 3 yields the following results Pb = 33, Zn = 9, Cd = 17, Cr=1.5, Cu = 5, Ni = 4. We know that the burning of leaded gasoline is responsible for the large increase of Pb. Enormous metal production of Zn and Cd ores as well as refuse incineration are responsible for the increases of these metals. In addition, marine aerosols are an important source of Cd (Li, 1981). Obviously, Cu-Ni production from ores increased during this period but not nearly as much as for Zn-Cd. Also, combustion of fossil fuels contributed somewhat to the increase of Cu and Ni. The main source of Cr is steel and iron manufacturing which appears to not be as important an impact on the atmospheric environment as sources for the other metals. The pollution sources of Cr are minimal as reflected in the balance between riverine input and marine sediment output (Li, 1981). 

The most abundant carbon-containing compound in the stratosphere and mesosphere is carbon dioxide (CO2). By interacting with infrared radiation, this gas plays an important role in the thermal budget of the atmosphere, and the 30% increase in its concentration resulting mainly from fossil fuel burning has provided a significant forcing to the climate system of about 1.5 Wm 2 (IPCC, 2001). Carbon dioxide does not play any substantial role in the chemistry of the atmosphere except in the lower thermosphere, where its photolysis is an important source of carbon monoxide (CO). This latter gas, which is also released at the Earth s surface by incomplete combustion (pollution) and is partially transported to the stratosphere, is converted to CO2 by reaction with the hydroxyl radical (OH). 

Several observations have shown that hydrogen is affected by pollution sources. The hydrogen molecule is an important product of incomplete combustion in several anthropogenic and natural processes. The production of H2 by industrial combustion and automobiles is estimated to vary from 15 Tg H2/yr (Novelli et al., 1999) to 25 Tg H2/yr (Schmidt, 1974). According to Crutzen et al. (1979) 9 to 21 Tg H2/yr are produced by forest and savanna burning, especially for agricultural purposes in tropical regions. 

Source Appendix G in C. Baukal, Industrial Combustion Pollution and Control, Marcel Dekker, New York, 2004. 

Impacts of major pollutant sources e.g. municipal wastewaters, urban runoff, combustion of fossil fuels) Source apportionment (quantitative)... 

Qian Z, He Q, Kong L, Xu F, Wei F, Chapman RS, Chen W, Edwmds RD, Bascom R (2007) Respiratory responses to diverse indoor combustion air pollution sources. Indoor Air 17 135-142 Raukas-Kivioja A, Raukas ES, Meren M, Ldt HM, Ronmark E, Lundback B (2007) AUeigic sensitization to common airborne aUeigens among adults in Estonia. Int Arch AUeigy Immunol 142 247-254... 

It is important to pinpoint the PAH source even in an environment where more than one pollutant source is evident. The following source-specific compounds have been used cyclopenta(cd)pyrene for automobile exhaust benzo(6)naphtho(2,l-d)thio-phene for hard coal combustion picene derivatives for brown coal combustion, and l-methyl-7-isopro-pylphenanthrene (retene) for wood combustion. 

There are over 280 million scrap tires produced annually in the United States. Of these over 100 million are used as fuel and most of these are burnt to supplement fuel use in cement and other rotary kiln operations. The cement process is particularly convenient for tire combustion because the reinforced steel wire in the tire tread can be a source of iron for the cement chemistry. Kilns burning tires must comply with the EPA s boiler and industrial furnace act and hence are heavily regulated as a pollution source. Table 6.3 gives a typical average composition of tires supplied by the Rubber Manufacturers Association of America. 

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