Major Air Pollutants

The most common and widespread anthropogenic pollutants currently emitted are sulfur dioxide (SO2), nitrogen oxides (NO ,), carbon monoxide (CO), carbon dioxide (CO2), volatile organic chemicals (hydrocarbons), particulates, lead, and a variety of toxic chemicals. Table 9.7 lists important air 

Sulfur and nitrogen oxides Fossil fuel combustion 

Ozone Atmospheric reactions between nitrogen oxides and organic compounds 

Source USEPA, Environmental Progress and Challenges EPA s Update, U.S. Environmental Protection Agency, Washington, DC, 1988. 

Air pollutants were categorized into two groups primary and secondary. Primary pollutants are emitted directly into the atmosphere, where they exert an adverse influence on human health or the environment. Of particular concern are primary pollutants emitted in large quantities carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen dioxide, hydrocarbons, and particulate matter. Once in the atmosphere, primary pollutants may react with other primary pollutants or atmospheric compounds such as water vapor to form secondary pollutants. Receiving a lot of press and attention is acid precipitation, which occurs when sulfur or nitrogen oxides react with water vapor in the atmosphere. 

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Inorganic chemical produced Major air pollution emissions... 

Bromine All of the bromine produced in the United States is extracted from naturally occurring brines by steam extraction. The major air pollution concern is H2S from the stripper if H2S is present in the brine. The H2S can either be oxidized to SO2 in a flare or sent to a sulfur recovery plant. 

Air pollution in the United States is regulated at federal, state, and local levels. Allowable concentrations of the major air pollutants are set by the U.S. Environmental Protection Agency (EPA) under the auspices of the Clean Air Act. States and localities implement pollution control plans in accordance with the provisions of the Clean Air Act in regions where air pollutant concentrations exceed the federal standards. Some states and localities have air pollution standards of their own, and in the past, such standards have occasionally been more stringent than those of the EPA. 

The environmental pollution in Ukraine has reached critical levels. Vehicles, power plants, steel mills and nonferrous metallurgy works are the major air polluters. Pesticides are responsible for much of the harm done to human health. 

The environmental pollution in transition economy countries has reached critical levels. Vehicles, power plants, steel mills and nonferrous metallurgy works are the major air polluters. Pesticides are responsible for much of the harm done to human health. Water pollution continues on a large scale. Very often the situation is disastrous because this country has a combination of energy-intensive industries, thermal power generation, and intensive agriculture, further aggravated by Chernobyl. 

Considerable time elapsed before there was general acceptance of Haagen-Smit s important discovery, in part because of its subtle nature. For the first time, a major air pollution problem was demonstrated to be caused by a pollutant generated in the atmosphere. Its effect often did not become apparent until many miles downwind from the source. (The same suspicion has been attached to sulfate-containing aerosols for many years, but the proof that the sulfate is damaging is not as well established.) In addition, a new pollution source, automobile exhaust, had been shown to be of prime importance. 

Figure 6-1. In addition to the site description, there is a statement of all the conditions being monitored, the m ods used, and the numerical specifications for the sampling probe, both for the sampling manifold and for the connections from the manifold to the instruments. A third page (not included here) shows a schematic drawing with the dimensions and locations of the bends in the ducting. The sampling-probe specifications currently in effect at four major air pollution control agencies are summarized in Table 6-4.

An integrated study should be conducted in which relative effects of all major air pollutants on materials are assessed. 

Through EU legislation, major air pollutants have been regulated. For example, through an EU Directive (EC 1999), the EU has estabhshed limit values for concentrations of sulfur dioxide, nitrogen dioxide and nitrogen oxides, particulate matter and lead, as well as alert thresholds for concentrations of sulfur dioxide and nitrogen oxide, in ambient air. Member States must take the measures necessary to ensure that concentrations of the pollutants in ambient air do not exceed the limit values. 

Respiration into the lung alveoli is the most important hazard for plant workers. The average lung has 300 million alveoli with a surface area of about 70 m, which is designed for rapid gas exchange. This alveolar surface area is about 40 times larger than the external skin area of a person. There has been a systematic study of the major air pollutants associated with the protection of industrial workers, as monitored by the OSHA and the ACGIH, and there are three well-documented measurements and databases ... 

Information presently available will allow only a first approximation to be made into the significance of air pollution on plant growth. To complicate an evaluation, very little is known about the impact of various pollutant combinations that might interact to determine the phytotoxicity of the mixtures. Current knowledge about the inhibitory effects of major air pollutants on apparent photosynthetic rates in plants is described below. The discussion includes observed plant responses to simple dual combinations of the pollutants. 

Although information concerning the inhibition of photosynthesis by air pollution is limited, we may gain perspective into the potential problem through appraising available data on the extent that CO2 uptake by oats, barley, and alfalfa canopies can be suppressed by short-term (a few hours) exposure to the major air pollutants and simple combinations investigated. 

The major air- pollutants as identified by a number of countries in recent years in connection with pollutant regulatory programs are (1) Particulate matter (2) nitrogen oxides (NOj) (3) sulfur oxides (SO ) (4) hydrocarbons and (5) carbon monoxide (CO). 

Most of the information on the effects of air pollution on humans comes from acute pollution episodes such as the ones in Donora and London. Illnesses may result from chemical irritation of the respiratory tract, with certain sensitive subpopulations being more affected (1) very young children, whose respiratory and circulatory systems are poorly developed, (2) the elderly, whose cardiorespiratory systems function poorly, and (3) people with cardiorespiratory diseases such as asthma, emphysema, and heart disease. Heavy smokers are also affected more adversely by air pollutants. In most cases the health problems are attributed to the combined action of particulates and sulfur dioxides (SO2) no one pollutant appears to be responsible. Table 4.2 summarizes some of the major air pollutants and their sources and effects. 

Formula S02 MW 64.06 CAS [7446-09-5] a major air pollutant produced when soft coals, oils, and automobile fuels bum used as a fumigating and bleaching agent colorless gas with a strong suffocating odor liquefies at -10°C solidifies at -72°C soluble in water (8.5% at 25°C), alcohol, ether, and chloroform highly toxic and a strong irritant. 

Kim, S.-C., 2001. Emission characteristic of dioxins/furans and major air pollutants from incinerators. J. Environ. Toxicol, (in Korean) Special Lecture in The Korean Society of Environmental Toxicology 2001. 

What are the fundamental building blocks of our shoes, ourselves, our consumer goods our universe What are major air pollutants we encounter every day and what effects can they have on us What is air What is clean air What is polluted air Why is methylisocyanate so harmful How can a molecule be benign and deadly at the same time ... 

Herschkovitz et al. ([69] Section 3.3.3.2) reported formaldehyde, a major air pollutant, detection in solution phase based on the coupling of a biosensor measuring device and a flow injection system. Amperometric formaldehyde sensor was constructed using screen-printed carbon ink electrodes modified with osmium-based hydrogel and then placing formaldehyde dehydrogenase immobilized nylon membrane directly onto the electrode. The sensor is selective, inexpensive, stable over several days, easy to construct and... 

Gordon, G. E., Study of the Emissions from Major Air Pollution Sources... 

Hazard Highly flammable, dangerous fire and explosion risk. Flammable limits in air 12-75% by volume. Toxic by inhalation. TLV 25 ppm. Note Carbon monoxide has an affinity for blood hemoglobin over 200 times that of oxygen. A major air pollutant. 

Based on the output of the conducted experiments, regional ecological standards for the quality of the atmosphere, with respect to the major air pollutants were developed, taking into account the risk for the land vegetation (trees and agricultural crops and plants) (Table... 

Introducing the major air pollutants The major chemicals that pollute the air are carbon monoxide, CO carbon dioxide, CO2 sulfur dioxide, SO2 nitrogen monoxide, NO nitrogen dioxide, NO2 hydrocarbons and suspended particles. 

I shall begin this presentation by reminding you of some of the major air pollution issues in which traffic plays a major role. 

The important inorganic compounds of carbon are the carbides the cyanides, most of which are extremely toxic carbon monoxide, also toxic and a major air pollutant the carbonates and bicarbonates and carbon dioxide, an end product of metabolism and a component of the global carbon cycle. 

The haze phenomenon in Southeast Asia is a major air pollution problem and its impacton the chemistry of precipitation is still unknown. It has been speculated that forest fires could raise the acidity of precipitation. While it is known that forest fires produce acid precursor gases such as SO2, NO and NO2, the non-carbonaceous matter of particles produced by these fires contains Ca and K, which give rise to alkalinity in rainwater. There is a need for a research project to study both the emissions from the forest fires in Southeast Asia and their impact on precipitation chemistry and rainfall acidity. 

Among sulfur-containing compounds, the toxic effects of sulfur dioxide have importance in practice. Sulfur dioxide belongs to the group of major air pollutants, and emissions from industry and ocean-going ships are the main sources of its input into the environment. 

Reactions in the Gas Phase VOCs are major air pollutants, and catalytic combustion is one of the most important technologies for eliminating low concentrations of VOCs in effluent systems [64] Platinum metal is the most active catalyst for hydrocarbon combustion and is widely used supported on AI2O3 and other oxides. It is important for this combustion to take place at low temperatures. However, the water vapor produced during combustion under these conditions can be adsorbed on the oxide support due to its hydrophilicity, which can negatively affect the catalytic activity of the metal. This activity can also be affected by humidity in the feeding stream. Hydrophobicity of carbon materials could overcome this problem, and activated carbons have been proposed as supports in VOC combustion [65,66]. 

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