Pollution is the introduction of contaminants
into an environment that causes instability, disorder, harm or
discomfort to the ecosystem i.e. physical systems or living organisms
which can come "in the form of chemical substances, or energy such as
noise, heat or light". "Pollutants can be naturally occurring
substances or energies, but are considered contaminants when in excess
of natural levels."
Environmental pollution is a problem both in developed and developing
countries. Factors such as population growth and urbanization
invariably place greater demands on the planet and stretch the use of
natural resources to the maximum.
Forms of pollution
The major forms of pollution are listed below along with the particular
pollutants relevant to each of them:
- Air pollution, the release of chemicals and particulates
into the atmosphere. Common gaseous air pollutants include carbon
monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen
oxides produced by industry and motor vehicles. Photochemical ozone and
smog are created as nitrogen oxides and hydrocarbons react to sunlight.
Particulate matter, or fine dust is characterized by their micrometer
size PM10 to PM2.5.
- Water pollution, by the release of waste products and
contaminants into surface runoff into river drainage systems, leaching
into groundwater, liquid spills, wastewater discharges, eutrophication
and littering.
- Soil contamination occurs when chemicals are released by
spill or underground leakage. Among the most significant soil
contaminants are hydrocarbons, heavy metals, MTBE, herbicides,
pesticides and chlorinated hydrocarbons.
- Littering
- Radioactive contamination, resulting from 20th century
activities in atomic physics, such as nuclear power generation and
nuclear weapons research, manufacture and deployment. (See alpha
emitters and actinides in the environment.)
- Noise pollution, which encompasses roadway noise, aircraft
noise, industrial noise as well as high-intensity sonar.
- Light pollution, includes light trespass, over-illumination
and astronomical interference.
- Visual pollution, which can refer to the presence of
overhead power lines, motorway billboards, scarred landforms (as from
strip mining), open storage of trash or municipal solid waste.
- Thermal pollution, is a temperature change in natural water
bodies caused by human influence, such as use of water as coolant in a
power plant.
Effects-
Air Pollution Effects
- Reduced lung functioning
- Irritation of eyes, nose, mouth and throat
- Asthma attacks
- Respiratory symptoms such as coughing and wheezing
- Increased respiratory disease such as bronchitis
- Reduced energy levels
- Headaches and dizziness
- Disruption of endocrine, reproductive and immune systems
- Neurobehavioral disorders
- Cardiovascular problems
- Cancer
- Premature death
Water Pollution Effects
Waterborne diseases caused by polluted drinking water:
- Typhoid
- Amoebiasis
- Giardiasis
- Ascariasis
- Hookworm
Waterborne diseases caused by polluted
beach water:
- Rashes, ear ache, pink eye
- Respiratory infections
- Hepatitis, encephalitis, gastroenteritis, diarrhoea,
vomiting, and stomach aches
Conditions related to water polluted by
chemicals (such as pesticides, hydrocarbons, persistent organic
pollutants, heavy metals etc):
- Cancer, incl. prostate cancer and non-Hodgkin's lymphoma
- Hormonal problems that can disrupt reproductive and
developmental processes
- Damage to the nervous system
- Liver and kidney damage
- Damage to the DNA
- Exposure to mercury (heavy metal):
>>In the womb: may cause neurological
problems including slower reflexes, learning deficits, delayed or
incomplete mental development, autism and brain damage
>>In adults: Parkinson's disease, multiple
sclerosis, Alzheimer's disease, heart disease, and even death
- Water pollution may also result from interactions between
water and contaminated soil, as well as from deposition of air
contaminants (such as acid rain)
- Damage to people may be caused by fish foods coming from
polluted water (a well known example is high mercury levels in fish)
- Damage to people may be caused by vegetable crops grown /
washed with polluted water (author's own conclusion)
Soil Pollution Effects
- Causes cancers including leukaemia
- Lead in soil is especially hazardous for young children
causing developmental damage to the brain
- Mercury can increase the risk of kidney damage; cyclodienes
can lead to liver toxicity
- Causes neuromuscular blockage as well as depression of the
central nervous system
- Also causes headaches, nausea, fatigue, eye irritation and
skin rash
- Contact with contaminated soil may be direct (from using
parks, schools etc) or indirect (by inhaling soil contaminants which
have vaporized)
- Soil pollution may also result from secondary contamination
of water supplies and from deposition of air contaminants (for example,
via acid rain)
- Contamination of crops grown in polluted soil brings up
problems with food security
- Since it is closely linked to water pollution, many effects
of soil contamination appear to be similar to the ones caused by water
contamination
Noise pollution Effects-
- Hearing defects.
- Insomnia
- Hypertension
- Ischemic heart disease
- Annoyance
- Headache
- Fatigue
- Vertigo
- Stress
Please click here to go back to the Home Page