Urban air pollution

Camufo, D., C. Daffara, and M. Sghedoni (2000), Archaeometry of air pollution Urban emission in Italy during the 17th century, /. Archaeol. Sci. 27, 685-690. 

Some members of the US Judeo-Christian religious community have long been concerned with public health, sustainable agriculture, water and air pollution, urban land use, and other issues now labeled environmental . However, the faith-based environmental movement traces its roots to January 1,1990, when Pope John Paul II said, Men and women... 

Referred to locally as the Alaskan Apple, Alaskans have a love/hate relationship with their only major city. For the frontiersmen living in the bush, Anchorage represents everything that they ve escaped from air pollution, urban sprawl and traffic jams. On the other hand, the city s residents themselves hold an inspired awe of their city - its beautiful vistas and surprisingly advanced arts and culinary scenes engendering a fierce local pride. 

Models can be used to study human exposure to air pollutants and to identify cost-effective control strategies. In many instances, the primary limitation on the accuracy of model results is not the model formulation, but the accuracy of the available input data (93). Another limitation is the inabiUty of models to account for the alterations in the spatial distribution of emissions that occurs when controls are appHed. The more detailed models are currendy able to describe the dynamics of unreactive pollutants in urban areas. 

Human-made sources cover a wide spectrum of chemical and physical activities and are the major contributors to urban air pollution. Air pollutants in the United States pour out from over 10 million vehicles, the refuse of over 250 million people, the generation of billions of kilowatts of electricity, and the production of innumerable products demanded by eveiyday living. Hundreds of millions of tons of air pollutants are generated annu ly in the United States alone. The five main classes of pollutants are particulates, sulfur dioxide, nitrogen oxides, volatile organic compounds, and carbon monoxide. Total emissions in the United States are summarized by source categoiy for the year 1993 in Table 25-10. 

Bornstein et al.. Simulation of Urban Earner Effects on Polluted Urban Boundary Layers Using the Three-Dimensional URBMET TVM Model with Urban Topography, Air Pollution Proceedings, 1993. 

Problems of air pollution exist on all scales from extremely local to global. These are divided in this chapter into five different scales local, urban, regional, continental, and global. The local scale includes up to about 5 km. The urban scale extends to the order of 50 km. The regional scale is from 50 to 500 km. Continental scales are from 500 to several thousand km. Of course, the global scale extends worldwide. 

There are two different types of air pollution problems in urban areas. One is the release of primary pollutants (those released directly from sources). The other is the formation of secondary pollutants (those that are formed through chemical reactions of the primary pollutants). 

At least three types of problems contribute to air pollution problems on the regional scale. One is the carryover of urban oxidant problems to the regional scale. With the existence of major metropolitan areas in close proximity, the air from one metropolitan area, containing both secondary pollutants formed through reactions and primary pollutants, flows on to the adjacent metropolitan area. The pollutants from the second area are then added on top of the "background" from the first. 

What are the two types of air pollution problems found in urban areas ... 

The other major aspect of air pollution reduction is the control of shortterm episodes on the urban scale. This aspect is called tactical because, prior to an episode, a scenario of tactical maneuvers must be developed... 

Brysson and co-workers (7) conducted a study in St. Louis, Missouri, on the effects of urban air pollution on the tensile strength of cotton duck material. Samples were exposed at seven locations for up to 1 year. Figure 9-3 shows the relationship between tensile strength and pollutant exposure. For two levels of ambient air exposure, the materials exhibited less than one-half their initial tensile strength when exposed to air pollution for 1 year. 

National Research Council, "Rethinking the Ozone Problem in Urban and Regional Air Pollution." National Academy Press, Washington, DC, 1991. 

Hundreds of chemical species are present in urban atmospheres. The gaseous air pollutants most commonly monitored are CO, O3, NO2, SO2, and nonmethane volatile organic compounds (NMVOCs), Measurement of specific hydrocarbon compounds is becoming routine in the United States for two reasons (1) their potential role as air toxics and (2) the need for detailed hydrocarbon data for control of urban ozone concentrations. Hydrochloric acid (HCl), ammonia (NH3), and hydrogen fluoride (HF) are occasionally measured. Calibration standards and procedures are available for all of these analytic techniques, ensuring the quality of the analytical results... 

Gryning, S. E., and Lyck, E., "Comparison between Dispersion Calculation Methods Based on In-Situ Meteorological Measurements and Results from Elevated- Source Tracer Experiments in an Urban Area." National Agency of Environmental Protection, Air Pollution Laboratory, MST Luft - A40. Riso National Laboratory, Denmark, 1980. 

Benarie, M. M., "Urban Air Pollution Modeling." MIT Press, Cambridge, MA, 1980. 

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. 

In view of the unforeseen growth in automobile emissions in urban areas combined with the serious air pollution problems in many urban areas, the Congress has made significant changes to the motor vehicle provisions on the 1977 Clean Air Act. 

Plan analysts and planners (air pollution control, environmental, urban, and unspecified). 

Although the original Clean Air Act of 1977 brought about significant improvements in air quality, the urban air pollution problems of ozone (known as smog), carbon monoxide (CO), and particulate matter (PM,o) persist. Currently, over 100 million Americans live in cities which are out of attaimnent with the public health standards for ozone. The most widespread and persistent urban... 

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