Pollution urban

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. 

Air pollution is principally a problem in urban and heavily industrialized areas, where the flow of clean air from surrounding areas is insufficient to disperse the accumulation. Motor vehicles account for more than 50% of the man-made emissions of carbon monoxide, hydrocarbons, and nitrogen oxides (4). More than half of the U.S. annual trillion vehicle miles are driven in urban areas (5). Nature produces much more pollutants than all man-made sources, but natural emissions are widely dispersed and do not contribute heavily to urban pollution problems (6, 7). 

Again, the myriad influences of human activity are usually viewed as separate effects (global warming, acid rain, ozone loss, urban pollution, etc.) However, these individual symptoms clearly have major interdependencies that must be understood if humans are to learn how to coexist with a stable Earth system. 

Martin V. Melosi. Environmental Crisis in the City The Relationship between Industrialization and Urban Pollution. In Triumph and Failure the American Response to the Urban Water Supply Problem, 1860-1923. Austin University of Texas Press, 1980. 

Thus the total soil pollution was connected with a respiratory system and a digestive tract. Both systems were also sensitive to such urban pollutants as heavy metals and PAH. For radionuclides the correlation with the given nosologies was not revealed. The asthma morbidity was mostly connected with soil pollution rates. This circumstance, apparently, can be related to nonspecific action of pollutants on a human organism, because the etiology of asthma is connected with the human immune defense system and allergy state (Roite, 1991). The last was shown for pesticides (Nikolaev et al., 1988) and heavy metals (Drouet et al., 1990). The sensitized immune system is, apparently, responsible for chronic toxic effects of other pollutants at low doses (Sidorenko et al., 1991 Novak and Magnussen, 1993). 

This report deals primarily with the origins and effects of ozone and other photochemical oxidants. It is limited, more or less, to the problem of urban pollution and to such closely related topics as natural background in the earth s boundary layer. No consideration is given to the stratospheric ozone layer and the effects produced by supersonic transport (sst) emission or halocarbons. 

In previous studies we found that improved emission-control devices (such as hot-side electrostatic precipitaters and wet-scrubber systems) now being installed on modern pulverized-coal-fired power plants modify the quantity, chemical composition, and distribution characteristics of fine aerosol emissions (12,13). Such modifications must be understood to adequately assess human health and environmental hazards, and to apportion the contributions of sources to urban pollutant inventories. 

In general, we feel that there are far too few studies of the composition of particles in the submicrometer region. More studies are needed to adequately characterize the human health and environmental hazards associated with utility coal combustion, and to more accurately determine their contribution to urban pollutant inventories. 

When the data were factor analyzed in abundance form, a weak Ca loading appeared on a factor that appears to be composed of urban pollutants from Champaign-Urbana, including Pb and Zn. This is of considerable interest, because urban concentrations of Ca and other crustal elements have been found to be enhanced over rural concentrations (11, 12, 13). Nevertheless, the factor analysis procedure used did not distinguish between rural soil and road sources of crustal elements. 

Masclet and co-workers (1986) have also developed a relative PAH decay index. They used it, for example, to identify various major sources of urban pollution and developed a model for PAH concentrations at receptor sites. An interesting and relevant area that is beyond the scope of this chapter is the use of PAHs as organic tracers and incorporating their relative decay rates (reactivities) into such receptor-source, chemical mass balance models. Use of relative rates can significantly improve such model performances (e.g., see Daisey et al., 1986 Masclet et al., 1986 Pistikopoulos et al., 1990a, 1990b Lee et al., 1993 Li and Kamens,... 

Sillman, S., and P. J. Samson, Impact of Temperature on Oxidant Photochemistry in Urban, Polluted Rural, and Remote Environments, J. Geophys. Res., 100, 11497-11508 (1995). 

The sources of urban pollutants are municipal sewage, runoff from city streets and landfills, and industrial effluents. Indirectly solvents contribute to municipal sewage, insofar as they comprise part of the landfill and runoffs. Mostly, industrial effluents have solvent components. 

Until the mid 1980 s the simple chemical species nitric oxide, NO, was generally associated with the numerous nitrogen oxides found in photochemical smog and other forms of urban pollution but was suddenly identified as an essential biological... 

Markkola, A. M., Ohtonen, R., Tarvainen, O. Ahonen-Jonnarth, U. (1995). Estimates of fungal biomass in Scots pine stands on an urban pollution gradient. New Phytologist, 131, 139-47. 

It includes wet and dry deposition processes and a simplified photochemical smog mechanism that is only applicable to regional and urban pollution. 

Hydrocarbons. Photochemical air pollution in many urban areas focuses attention on nitrogen oxides and hydrocarbons. Globally sources of hydrocarbons include not only the urban pollutant sources but also major natural sources. 

Pooler, F. Jr., A Prediction Model of Mean Urban Pollution for Use with... 

Sillman S. and Samson P. J. (1995) The impact of temperature on oxidant formation in urban, polluted rural, and remote environments. ]. Geophys. Res. 100, 11497-11508. 

J. Tarr, The Search for the Ultimate Sink Urban Pollution in Historical Perspective, University of Akron Press, Akron, OH, 1996. 

Calderongarciduenas L, Osnaya N, Ro-driguezalcaraz A, Villarrealcalderon A. 1997. DNA damage in nasal respiratory epithelium from children exposed to urban pollution. Environ. Mol. Mutagen. 

Table 8.3 Sprawl and Urban Pollutants in U.S. Drinking Water...

Different variables affect the intensity of solar radiation. As the emission of solar radiation is considered constant, the summer sun is stronger than the winter sun, the sun on the equator stronger than the sun in Lapland, and the midday sun burns more than the afternoon sun. Eog does not slow down UV penetration, but urban pollution is, on the contrary, a powerful sunblock because of the presence of aromatic hydrocarbons, which make excellent UV blocks. Altitude in itself has less influence than the angle of incidence, but snow, on the other hand, reflects 85% of UV rays, whereas dry sand only reflects 17%, water 5% and grass 2%. Therefore, places lying between snow-covered mountains on a very sunny day are particularly dangerous. 

Factors which are currently affecting environmental quality in Lake Pontchartraln are generally those related to urban development and urban pollution, altered land use patterns, and hydrologic modification within the lake s watershed. Paramount... 

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