AIR POLLUTION SOURCES 93
Part 1. Pollutant Emissions (continued)Pollutant types Sources and abundance Abatement and control
oxygen from the lungs through the circulatory system.
Small particulates are also detrimental to health by
having adsorbed toxic materials on their surfaces; the
particulates are then inhaled into the body. Particulates
are also responsible for soiling of materials and
reduced visibility.
In July 1987, the U.S. Environmental Protection Agency
promulgated revised national ambient air quality
standard for particulate matter. The new standard
placed emphasis on particles less than10 microns in
diameter. This revision was based on the finding that
fine particulates of less than 10 microns (also known
as PM-10) pose a greater hazard to human health than
larger particles, because it is these smaller particles
that penetrate deep into the lungs. In addition, because
of their ability to remain airborne and their refractive
properties, the smaller particles also have a greater
impact on visibility.
In July 1997, based on studies which indicated adverse
health effects from the inhalation of very fine
particles, the U.S. EPA promulgated a PM-2.5
standard.Naturally occurring sources of particulates are
due to forest fires and windblown dust.
Mechanical processes such as wind erosion,
grinding, spraying, demolition, industrial
activity and salt also contribute to particulate
problems. Most of these particulates are in
the 1–10 micron range and generally
predominate very near the source. Electricity
generation, forest product industries,
agriculture and its related operations, the
crushed stone industry, the cement industry,
the iron and steel industry and asbestos
mining are other important examples.
Surface coating sources emit spray and mist
pollutants. These pollutants include organic
solvent bases that are used in paints. These
volatile organic solvents become airborne
during the application of paints to their
intended surface.pollution control equipment and the
wetting down of working surfaces
with water or oil.
c) Disposal of solid waste by sanitary
land fill, composting, shredding and
grinding rather than incineration.
Mobile Sources: The aim is to develop
methods of achieving complete
combustion. If this is accomplished,
particulates (like soot and smoke)
would be minimal. To achieve
maximum combustion, vehicles in
the United States are equipped with
catalytic converters which help to
completely incinerate unburned fuel.
In the U.S. and in many other
countries like Canada, Britain and
Germany unleaded gasoline is
available for use in automobiles. Less
lead in the gasoline means less lead
particles being emitted into the air.
The following are examples of some
typical particulate pollutants.1940 1950 1960 1970 1980 1990
Ye a r
Remaining Categories
Waste Disposal & Recycling
Fuel Comb.—Ind.
Fuel Comb.—Elec. Util.Fuel Comb.—Other
Non-Road Sources
Miscellaneous (primarily fires)
Other Industrial ProcessPoint and fugitive process emissions(million short tons)051015201985 1990
YearWind Erosion
Remaining Categories
Paved Roads
Agriculture
Unpaved Roads
051015202530354045505560Fugitive dust emissions (million short tons)FIGURE 3 Trend in particulate Matter (PM-10) by point and fugitive process sources (1940 to 1994), and by fugitive dust sources (1985
to 1994).Pollutant types Sources and abundance Abatement and control- Aeroallergens: Aeroallergens (pollens) are airborne
materials that elicit a hypersensitivity or allergic
response in susceptible individuals. The most
common aeroallergens are the pollens of wind-
pollinated plants—especially ragweed pollen, which
is the main cause of hay fever. In addition to the
pollens, aeroallergens include molds, danders, house,
cosmetics, and others. It has been estimated that
Most aeroallergens are produced by natural
causes, although some may be produced
through man-made interferences
1) Natural sources. The aeroallergens
encompass a wide variety of materials, but
pollens are the most important member of
this group.Abatement and control measures for
aeroallergens have been directed
primarily at the ragweed. Since
ragweed grows quickly in areas
where the soil has been disturbed, it
is not controlled by pulling it up
when noticed, since the soil is thus
disturbed and the growth may be
heavier the following year.
(continued)C001_006_r03.indd 93C001_006_r03.indd 93 11/23/2005 9:42:40 AM11/23/2005 9: