Pollution
The word pollute, comes from the Latin word Pollutus meaning “made foul, unclean, or dirty.”
Pollutus was historically used to describe sewage or wastes that contaminate air water or land.
Pollution can affect all aspects of the environment that is both subtle and obvious.
It is important to know the types of pollutants and how they affect the environment and the
health of living organisms.(Cunningham William P)
Water pollution
Water pollution is the contamination of any body of water including ground water, by substances
not found in the body of water and can adversely effect of the natural environment and on human
health. There are many types of pollutants that end up in water these are classed as point source
that comes from industrial plants, or municipal discharges; and non-point source that comes from
runoff this can be from storm water that erodes soil and picks up land pollutants to be carried to
creeks, rivers, lakes where it settles to the bottom and smothers the organisms that feed and breed
there. Ground water can be contaminated by leaky underground chemical-storage tanks.
Synthetic organic chemicals like petroleum products and pesticides are major sources of toxic
pollution the most common are from urban runoff, agricultural runoff, and industrial discharge.
Oil spills like the Exxon Valdez in 1989 near Alaska was a major toxic pollutant.
Effects on natural bodies of water
This depends on the type of contaminant and the type of body of water that receives it, rivers and
streams are self-flushing fresh water with quality from pristine mountain streams to organic and
nutrient laden coastal rivers, these waters serve many uses including human water supply,
ecological support of fish and wildlife, recreation, industrial use, and waste assimilation.(John
Randolph)
Toxic and hazardous chemicals:
Humans have created and released toxic and hazardous chemicals into the environment for long
time.
Environmental pollution is any discharge of material or energy into water, land, or air that
causes or may cause short term or long term detriment to the Earth’s ecological balance or that
lowers the quality of life.
Hazardous chemicals are dangerous because they are flammable, explosive, strong irritants,
sensitizers, or acids and bases.
Toxic chemicals disrupt specific cellular processes in living organisms.
Acute toxicity refers to exposure to a chemical that will kill an organism in a short time with a
single dose.
People exposed to carcinogens, chemicals or physical factors that cause cancer can sometimes
develop cancer soon after exposure, and the link between the chemical and the cancer is easier to
determine, as in the people exposed to asbestos.
Persistent organic pollutants:
Chlorinated hydrocarbons have an affinity for fat, many of these chemicals are stored and
concentrated as organisms ear one another, until they eventually reach toxic concentrations in
predators at the top of the food chain, such as people, polar bears, whales, and eagles. It has been
shown that DDT and several of its chemical cousins interfere with shell formation by blocking
the action of normal hormones in birds. While this hormone disruption by these chemicals has
not been proven to affect humans, it is logical to think it can because the physiological processes
are similar.
Organic solvents like: benzene, chloroform, carbon tetrachloride, trichloroethylene have been
used as degreasers, dry cleaning solvents, thinners, and other industrial applications. Chronic
exposure to these has been linked to serious health problems.
Metals:
Many metals like mercury, cadmium, chromium, and nickel are highly toxic and persist in the
environment. In the 1950’s Minamata Bay, Japan became synonomous with mercury poisoning.
A local company had been dumping mercury-contaminated wastewater, assuming the metal was
inert and innocuous. Microorganisms absorbed the mercury and it moved through the food chain
until it reached toxic levels in the fish eaten by villagers. The mercury tainted fish caused
permanent brain damage, physical and mental retardation, and death for some of the villagers.
Mercury remains a hazard in some parts of the world. Lead is another serious pollutant, lead
based products are no longer made in the US but lead is found on older houses or in the soil
around city streets and freeways. As little as ten parts of lead per billion in the blood can have
adverse effects on mental development of young children, once the damage is done it is usually
irreversible. (Cunningham William P)
Radioactivity
Radiation enters the environment from a wide variety of sources, the most well-known are from
the detonation of nuclear weapons and the controlled release of energy by nuclear reactors. Other
sources of radiation include the mining of uranium minerals, by-products of mining and
processing operations, spent-fuel reprocessing plants, and experimental research laboratories.
The USA has about 181 million metric tons of nuclear waste left over from weapons production
and nuclear power plant operations.(Cunningham William P)
Under normal conditions nuclear power plant release very little radiation.
In 1979 there was an nuclear accident at Three Mile Island nuclear power plant near Harrisburg,
PA and in 1986 the Chernobyl reactor in the Ukraine discharged 6.4 metric tons of highly
radioactive fuel. Another is radon this is a type of gas that is released during the breakdown of
uranium deposits in many types of rocks, and in the decomposition of radium and uranium. This
gas seeps into homes through basements, and foundations and if not ventilated properly if built
up enough can cause lung cancer.
Unconventional pollutants
There are several types of unconventional pollutants like noise, light, and visual blight.
Noise in urban areas such as highway traffic, general street traffic, sirens, alarms, construction
noise, loudspeakers, jet planes; are a source of stress. Evidence suggests that noise-related stress
causes a wide range of psychological and physiological problems ranging from irritability to
heart-disease. By the age of 40 most Americans have suffered from hearing loss.
Lights
Cities have innumerable lights and many inner-city people have never seen the milky-way or a
star filled sky. Astronomers are finding it more difficult to see through the glow of large cities.
Visiual blight
The jumble of advertising signs, clashing of architectural styles, ugly buildings, factories,
garbage, litter, and abandoned buildings can be regarded as visual pollution. This type of
pollution is not just in the big cities, a sea of tree stumps that used to be a forest, power lines,
windmills, oil wells, mines, and other energy producing facilities ruin beautiful rural vistas.
Visual pollution can be hard to define and harder to regulate because different people find
different things visually offensive.
Air pollution
Most air pollution is caused by humans, but natural processes like forest fires pollute the air.
Common air pollutants are:
Carbon monoxide, an odorless colorless gas that is produced by the combustion or burning of
petroleum products, including heating oil, gasoline, and diesel fuel. Cars and other types of
engines produce a significant amount of carbon monoxide.
Sulfur oxides, are gases produced by a combustion of fuels that have sulfur like coal, heavy fuel
oil, and industrial smelting plants and facilities that produce a form of coal used in blast furnaces.
Nitrogen oxide, are produces by the combustion of fossil fuels like gasoline.
Small air-borne particles known as soot are formed by the combustion of coal used by electric
power generators and heavy industry.
Volatile organic compounds, are formed by the evaporation of petroleum derived chemical
products such as gasoline and other fuels, solvents, and oil based paints.
Ammonia gas, happens in the industrial emissions and the volatile emissions from animal
wastes, especially at large animal holding facilities. The animal waste may collect in a field,
feedlot or lagoon but evaporates into a gaseous form on hot days.
Some of these primary pollutants can undergo chemical reactions in the air and form into a
secondary pollutant. Many air pollutants in high concentrations, can cause health problems such
as air-borne lead can cause learning disabilities, behavioral problems, slowed growth in children,
high blood pressure, nerve disorders in adults.
Carbon dioxide has been increasing since the 18th century with the clearing of forests, fossil fuel
usage and the increase in population of people and animals, with the increase of carbon dioxide it
causes the Earth’s temperature to rise. There is much debate over how this warming has affected
the Earths’ climate and what the future will be if the current trend keeps going.
Pollution control
Pollution control is the management of waste materials in order to minimize the effects of
pollutants on people and the environment. The United States has done a lot to control noticeable
pollution of the air, water, and land. However the remaining toxic pollutants like trace pesticides,
dioxins, and heavy metals; still remain a problem and large-scale problems like acid rain,
depletion of the ozone layer and industrial pollution in other developing countries remains a
problem.
There are four historic technical approaches to pollution control. First was the use of taller
smokestacks and longer effluent pipes to disperse pollutants. This worked to lessen the
concentration of pollution but this method did not help reduce pollution. Second was to curtail
pollution generating activities during high pollution conditions. This did not work as a long term
solution because it increased high pollution episodes. Third was to reduce the pollutants through
use of treatment facilities. This method is successful at reducing air and water pollutant
discharges and improved the levels of air and water quality, but pollution from land runoff and
small sources of toxic air pollutants are found to be more difficult and expensive to control.
Fourth was to prevent pollution by changing industrial processes or the ways of doing things.
This focus is used to redesign and reinventing ways to improve economic efficiency and prevent
the generation of pollution. (Randolph J)
Works Cited
Cunningham, William P. "Pollution, Environmental." Grolier Multimedia Encyclopedia. Grolier
Online, 2012. Web. 1 May. 2012.
Lansford, Henry. "Environmental Pollution." The New Book of Popular Science. Grolier Online,
2012. Web. 1 May. 2012.
Randolph, John. "Pollution Control." Grolier Multimedia Encyclopedia. Grolier Online, 2012.
Web. 1 May. 2012.
Randolph, John. "Pollution, Water." Grolier Multimedia Encyclopedia. Grolier Online, 2012.
Web. 1 May. 2012.
Schmitz, Richard J. "Water Pollution." Encyclopedia Americana. Grolier Online, 2012. Web. 30
Apr. 2012.
Zipper, Carl E. "Pollution, Air." Grolier Multimedia Encyclopedia. Grolier Online, 2012. Web. 1
May. 2012.