Theodore Parker Sr.
What is air pollution?
Air pollution is substance in our atmosphere consisting of man-made contaminants that may be harmful to humans, plants, animal life or property. Air pollution consists of
gaseous material
which makes up more than 90% of the total of air pollution. Air pollution consists of
suspended particulates
which make up less than 10% of the total of air pollution.
Gaseous Material: Sources and Effects
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Carbon Monoxide
CO—( over 50% of total of U.S. air pollution) colorless, odorless, tasteless.
Sources:
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1) automobile engines account for 50% of world total (three pounds of CO released for each gallon of gasoline burned)
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2) Industry 20%
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3) Incomplete fossil fuel combustion
Effects:
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1) Low concentrations cause drowsiness, dizziness, nausea and contributes to driver fatigue.
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2) 10 parts per million—illness reaction time slowed
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3) 50 parts per million—eight hour exposure reduces the oxygen carrying capacity of the blood by 15%.
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4) 120 parts per million—one hour exposure can affect driver responses noticeably. (rush hour concentrations often exceed 300 parts per million)
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5) 1,300 parts per million—fatal in thirty minutes.
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6) persons with heart disease, anemia or respiratory disease are most sensitive to the effects of carbon monoxide.
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7) contributes to photochemical smog.
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Hydrocarbons
—a class of compounds containing carbon and hydrogen in various combinations. Found mainly in oil, natural gas and coal.
Sources:
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1) automobiles and other motor driven sources—55% (over 200 different kinds of hydrocarbons are found in auto exhaust)
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2) bacterial decomposition*
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3) forest fires*
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4) combustion processes*
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* % variable
Effects:
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1) many hydrocarbons are cancer producing (carcinogenic).
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2) detrimental to balance of the ozone layer in the atmosphere.
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3) contributes to photochemical smog.
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Nitrogen Oxides
—reddish brown gas with a characteristic odor.
Sources:
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1) internal combustion engines—39%
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2) residential and commercial burning—47%
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3) natural processes—14%
Effects:
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1) nitrous oxide, like carbon monoxide reduces the oxygen carrying capacity of the blood.
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2) nitrogen dioxide can be fatal in high concentrations.
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3) increased respiratory infections in children (mainly bronchitis).
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4) nitrogen dioxide and water combine to form nitric acid
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5) the oxides of nitrogen combine with water on mucous membranes to
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form mild acid solutions. This leads to irritation of the eyes, nose, bronchial tubes and lungs.
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Sulfur Dioxide—
SO2 a heavy , pungent, colorless gas.
Sources:
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1) burning of coal and oil as well as other industrial processes.
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2) natural decay and volcanic eruptions.
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3) smelting and petroleum refining.
Effects:
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1) pulmonary damage
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2) irritation to eyes, nose and throat.
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3) kills plant life (damages leaves and stems)
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4) can injure the bronchial tubes leading to the lungs and the delicate tissues of the lungs themselves.
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5) affects the PH balance of water.
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6) forms sulfuric acid with water. This acid attacks metal, concrete, granite and other structural materials.
Suspended Particulates: Sources and Effects
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Particulates
—solid or liquid matter, including dust, smoke fumes, fly ash, mists and sprays.
Sources:
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1) incinerators and fossil fuel burning plants, especially coal burning operations.
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2) industrial processes.
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3) automobile exhaust.
Effects:
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1) disturbs the normal cleansing action of the lungs.
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2) particles often carry or contain materials that have direct toxic effects on humans (particles often contain bacteria, viruses, sulfuric and nitric acids).
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3) particles suspended in the air scatter and absorb sunlight, produce haze, reduce visibility and reduce solar energy reaching earth.
Photochemical Smog
Sources: Photochemical smog is secondary air pollutant produced by the chemical reaction due to the combining of hydrocarbons, carbon monoxide, nitrogen oxides and particulates. The smog making process begins when the sun’s ultra-violet rays trigger a photochemical reaction between hydrocarbons and nitrogen oxides, forming a number of secondary pollutants or
smog products such as ozone, aldehydes and peroxy-acynitrate (PAN).
Effects:
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1) ozone can cause coughing, choking, headaches and severe fatigue.
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2) ozone can damage the leaves of plants.
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3) PAN causes eye irritation and damages the leaves of plants.
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4) aldehydes, with their suffocating, pungent odor, cause severe respiratory irritation.
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5) photochemical smog with its brownish haze causes discomfort and decreases visibility.
Lead Aerosol
Sources: tetra-ethyl lead is the anti-knock compound in leaded gasolines that is responsible for 95% of the lead aerosol in the air.
Effects:
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1) exposure to high levels of lead aerosols causes scarring and shrinking of kidney and liver tissue.
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2) over-exposure to lead can result in peripheral nerve system damage affecting primarily motor nerves.
