Sources of pollution

Existing methods for monitoring the transport of gases were inadequate for studying aerosols. To solve the problem, qualitative and quantitative information were needed to determine the sources of pollutants and their net contribution to the total dry deposition at a given location. Eventually the methods developed in this study could be used to evaluate models that estimate the contributions of point sources of pollution to the level of pollution at designated locations. 

Vapors emitted from the materials of closed storage and exhibit cases have been a frequent source of pollution problems. Oak wood, which in the past was often used for the constmction of such cases, emits a significant amount of organic acid vapors, including formic and acetic acids, which have caused corrosion of metal objects, as well as shell and mineral specimens in natural history collections. Plywood and particle board, especially those with a urea—formaldehyde adhesive, similarly often emit appreciable amounts of corrosive vapors. Sealing of these materials has proven to be not sufficiently rehable to prevent the problem, and generally thek use for these purposes is not considered acceptable practice. 

Part 403 general pretreatment regulations for existing and new sources of pollution Part 411 cement manufacturing point source category Part 413 electroplating point source category... 

Clean Air Act of 1970 The Clean Air Act of 1970 was founded on the concept of attaining National Ambient Air Quahty Standards (NAAQS). Data were accumulated and analyzed to establish the quality of the air, identify sources of pollution, determine how pollutants disperse and interac t in the ambient air, and define reduc tions and controls necessary to achieve air-quahty objectives. 

Bubble Policy The bubble concept introduced under PSD provisions of the Clean Air Act Amendments of 1977 was formally proposed as EPA policy on Jan. 18, 1979, the final policy statement being issued on Dec. 11, 1979. The bubble pohcy allows a company to find the most efficient way to control a plant s emissions as a whole rather than by meeting individual point-source requirements. If it is found less expensive to tighten control of a pollutant at one point and relax controls at another, this woiild be possible as long as the total pollution from the plant woiild not exceed the sum of the current hmits on individual point sources of pollution in the plant. Properly apphed, this approach would promote greater economic efficiency and increased technological innovation. 

The oceans of the world are an important natural source of pollutant material. The ocean is continually emitting aerosols to the atmosphere, in the form of salt particles, which are corrosive to metals and paints. The action of waves on rocks reduces them to sand, which may eventually become airborne. Even the shells washed up on the beach are eroded by wave and tidal action until they are reduced to such a small size that they too may become airborne. 

Valid emission factors for each source of pollution are the key to the emission inventory. It is not uncommon to find emission factors differing by 50%, depending on the researcher, variables at the time of emission measurement, etc. Since it is possible to reduce the estimating errors in the... 

The third category for interactions is high dose (III). The effects produced by this level of interaction can be seen by the casual observer. The result of high-dose exposure is destruction or severe injury of the forest system. High-dose conditions are almost always associated with point source emissions. The pollutants most often involved are SO2 and hydrogen fluoride. Historically, the most harmful sources of pollution for surrounding forest ecosystems have been smelters and aluminum reduction plants. 

Examples of industrial chemical waste are given in Table 16.1. Common industrial sources of pollution are given in Table 16.2. Since waste can result in pollution, the two terms are often used synonymously. 

Emissions to the atmosphere from ammonia plants include sulfur dioxide (SOj), nitrogen oxides (NOJ, carbon monoxide (CO), carbon dioxide (COj), hydrogen sulfide (HjS), volatile organic compounds (VOCs), particulate matter, methane, hydrogen cyanide, and ammonia. The two primary sources of pollutants, with typical reported values, in kilograms per ton (kg/t) for the important pollutants, are as follows ... 

Point Source a source of pollution that is well defined, such as the smokestack of a coal-fired power plant or smelter. 

Outdoor inhalation exposure is mainly due to traffic, energy production, heating, and natural factors such as pollen and mineral dusts. These outdoor sources of pollution also affect indoor air quality. The indoor concentration is typically 20-70% of the corresponding outdoor concentration. Occasionally the indoor concentrations of an external pollutant (especially radon) may even exceed the concentrations outdoors. ... 

In large facilities and offshore platforms where the escaping gases and liquids could present a source of pollution or ignition, it is common to route the relief valve discharges into a common header that discharges at a remote safe location. Often a vent scrubber is installed in this header to separate the bulk of the liquids and to minimize the possibility of liquid discharges to atmosphere. 

ASTDR s mission is to prevent exposure and adverse human health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment. 

A more flexible 24-hour standard of 65 micrograms, revised from the original USEPA proposal, will give greater flexibility to individual sources of pollution, while still ensuring that the health of the American people is protected... 

As treated in other chapters of this book, air masses often transport acidic pollutants thousands of kilometres from their original source prior to deposition. Because air mass and storm movements tend to follow regular patterns, there is a strong linkage between the sources of pollutants and the areas that receive the acidic deposition. In eastern North America, the air mass movements and storm tracks are, on the average, from southwest towards the northeast. This serves to carry the emitted pollutants from the industrial "heartland over the more rural and comparatively pristine area of the northeast United States and southeastern Qmada (14). The spatial distribution of sulphate deposition over the eastern United States and Canada in 1980 is shown in Figure 4 (17). 

Overall the results reported in this review indicate that water scarcity might increase metal exposure (due to low dilution), metal uptake (due to higher retention under low flow), and metal toxicity and/or accumulation (depending on the dose and time of exposure), but also might cause opposite effects depending on the source of pollution. In addition, water scarcity will influence nutrient loads and will also modulate the fate and effects of metals. Thus, future studies addressing the role of environmental stress on the effects of toxicants at community scale are key to predict the impact of toxicants in the aquatic ecosystems. 

Although the major concern about the fate of organic pollntants in soil has been about pesticides in agricultural soils, other scenarios are also important. The disposal of wastes on land (e.g., at landfill sites) has raised questions about movement of pollutants contained in them into the air or neighboring rivers or water conrses. The presence of polychlorinated biphenyls (PCBs) or PAHs in snch wastes can be a significant source of pollution. Likewise, the disposal of some industrial wastes in landfill sites (e.g., by the chemical industry) raises questions about movement into air or water and needs to be carefully controlled and monitored. 

The principal source of pollution by polybrominated biphenyls (PBBs) has been the commercial mixture Firemaster, which was produced in the United States between 1970 and 1974. Production was discontinued in 1974 following a severe pollution incident in Michigan, when Firemaster was accidentally mixed with cattle feed on a farm. In due course, PBBs entered the human food chain via contaminated animal products. Substantial residues were found in humans from the area, and were snbse-quently found to be highly persistent. 

Local exhaust ventilation serves to remove a contaminant near its source of emission into the atmosphere of a workplace. A system normally comprises a hood, ducting which conveys exhausted air and contaminants, a fan, equipment for contaminants collection/ removal and a stack for dispersion of decontaminated air. Hoods normally comprise an enclosure, a booth, a captor hood or a receptor hood. Those relying on other than complete enclosure should be as close a practicable to the source of pollution to achieve maximum efficiency. 

No operator should work between the source of pollutant and the rear of the booth (i.e. all work should be handled from the front open face, as illustrated by Figure 11.1). 

If enclosure or use of a booth is impracticable, a captor hood is used. This is placed some distance from the source of pollution and the rate of air flow needs to be such as to capture contaminants at the furthermost point of origin. 

Examples of industrial chemical waste are given in Table 13.1. Common industrial sources of pollution are given in Table 13.2. Since waste can result in pollution, the two terms are often used synonymously. Wastes can be in the form of solid, liquid or gas, or any combination, e.g. solid waste comprises liquid slurries, sludges, thixotropic solids and solids of varying particle sizes. Typical examples are given in Table 13.3. 

S / S than ores of zinc (ZnS) have. Thus, the value of S / S in atmospheric SO2 can identify whether the source of pollutant was an iron or zinc smelting operation. 

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