Pollution sources indirect

Trace element analysis Trace element analysis is an indirect technique that seeks to infer the sources of sulfur pollution by measuring other chemical elements emitted along with the sulfur. The technique is based on the fact that different pollution sources emit characteristic chemical "signatures" (characteristic amounts and types of chemical elements) that depend on the type of fuel burned. For example, the pollution from coal-fired plants is relatively high in selenium, an element chemically similar to sulfur pollution from oil-fired plants is relatively low in selenium. By measuring the levels of such elements in polluted air, it is in principle possible to infer whether the pollution came predominantly from coal-fired sources (and therefore predominantly from the Midwest) or from oil-fired sources (and therefore chiefly from the Northeast). (A similar technique has been used to trace oil spills, based on the fact that the oil in each ship s hold is a chemically unique mixture). 

Humans may also be indirectly affected through exposure to increased levels of toxic metals in drinking water and food. Increased levels of toxic metal are a consequence of direct deposition of pollutants into water sources, increased leaching of metal from soils and lake sediments, and increased corrosion of water pipes. 

Sources of land pollution include direct dumping of domestic and industrial solid waste, excessive application of agrochemicals, and indirect contamination resulting from leaks or from leaching of hazardous components from liquid waste disposal sites or from atmospheric fallout. Land may also become contaminated by chemicals processed, stored or dumped at the site, perhaps in the distant past. Such contamination may pose a health risk to workers on the site, those subsequently involved in building, construction or engineering works, or the public (e.g. arising from trespass), and to animals. 

The CWA21 imposes pollutant limitations for all discharges of wastewater from identifiable ( point ) sources into the nation s waterways. These discharges are defined as either direct discharges, indirect discharges, or zero discharges. 

At the heart of the problem of relating improvements in air quality to reductions in pollutant emission is a reliable method of prediction. Only with such a method can there be rational planning for air pollution control through regulation of transportation, indirect sources, and stationary sources. Decision-makers need it as a tool and must specify it in their regulations. Otherwise, their administration of an air quality plan would be based on sheer guesswork tempered by political negotiation. 

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. 

The most important industrial alkalis are the weak alkali ammonia (Section 9.3), caustic soda (sodium hydroxide), and lime (calcium oxide).1-6 For many industrial and agricultural purposes, the most economical source of alkali is lime, which is used in steelmaking and other metallurgical operations ( 45% of U.S. production of lime), in control of air pollution from smokestack gases (Chapter 8), in water and sewage treatment (Sections 9.6 and 14.5), in pulp and paper production (Section 10.4), in reduction of soil acidity, in cement and concrete manufacture (indirectly, as discussed later), and in many chemical processes such as paper making (Section 10.4). In short, lime is one of the most important of all chemical commodities. 

Historically, the combustion of fossil fuels has directly or indirectly been the source of air contaminants at three levels local, regional, and global. Pollutants of importance at the local level have included sulfur dioxide and trace metals. Local forest damage is confined to a zone of a few km immediately surrounding a facility and for a distance of several to tens of km downwind. 

Indirect Sources Air, water, and soil can become polluted from a variety of indirect sources. Motor vehicles and factory smokestacks release gases that can indirectly cause many different types of pollution. The acidic gases that are produced (sulfur dioxide and nitrogen oxides) dissolve and contribute to the formation of acid rain. The concentrations of ions in ground water are affected by how acidic the water is. 

Most of the pollutants listed in this chapter find their way into water directly by human or natural discharges (from diffuse or point sources) or indirectly through discharges into soil. It is therefore important to realize that in order to manage or control such direct or indirect pollution, the chemistry of such chemicals must be understood and their physicochemical behavior in soil-water systems predicted. To accomplish these tasks, and to minimize adverse effects on the environment, one needs to have a background in water chemistry, soil mineralogy, soil surface chemistry, and the... 

Toxic Pollutant Standards for Indirect Discharge Point Sources... 

EPA. 1993h. Toxic Pollutant Standards for Indirect Discharge Point Sources. Organic Chemicals, Plastics, and Synthetic Fibers. Subpart K - Indirect Discharge Point Sources. U.S. Environmental Protection Agency. Code of Federal Regulations. 40 CFR 414.111. 

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