Pollution is an unwelcome
concentration of substances that are beyond the
environment's capacity to handle. These
substances are detrimental to people and other
In an undisturbed ecosystem,
all substances are processed through an intricate
network of biogeochemical cycles, such as the
nitrogen and carbon cycles. During these cycles,
substances are taken up by plants, move through
the food chain to larger and more complex
organisms, and when the latter die, are
decomposed (broken down) into simpler forms to be
used again when they are taken up by plants.
Biodegradable substances are those that can be
broken down by the environment's biological
systems. Pollution occurs when the environment
becomes overloaded beyond the capacity of these
normal processing systems.
* An excess of normally helpful substances, such
as the nutrients nitrogen and phosphorus.
* An excess of substances that
are harmless, and perhaps even necessary in tiny
amounts, but toxic in concentration. Copper, for
example, is necessary in small amounts for
healthy plant growth, but becomes a pollutant if
it occurs in greater quantities.
* Synthetic (human made)
compounds that are poisonous in the environment,
often even in trace amounts, such as DDT, dioxin,
PCBs and organochlorines (see Enviro Facts
"Toxic waste" and "Poison, farmers
* Substances that, in any
amount, are not biodegradable, such as plastics
and highly persistent chemicals like DDT and
Some pollutants kill living
organisms outright, other sub-lethal pollutants
do not kill, but may cause long-term biological
damage, interfere with organisms' reproductive
cycle, or make them more vulnerable to disease.
TYPES OF POLLUTION
Pollutants can be grouped according to the main
ecosystem which they affect. One pollutant often
affects more than one ecosystem.
Sulphur dioxide produced through the burning of
coal, causes acid rain and respiratory problems.
Nitrogen oxides and volatile hydrocarbons from
vehicle emissions, combine to form photochemical
smog which causes respiratory problems. Carbon
monoxide from vehicle emissions, restricts oxygen
uptake, causes drowsiness, headaches, death.
Carbon dioxide produced during the burning of
coal enhances global warming. CFCs used and
aerosols, refrigeration, airconditioning and
foam- blowing industries destroys the ozone
layer. Methane from feedlots and rubbish dumps
enhances global warming. Noise from industry and
traffic affects hearing and is stressful.
Sewage contains pathogens which cause typhoid,
cholera and gastroenteritis if there is
inadequate sanitation. Nutrients in sewage cause
eutrophication. Fertilizers used in agriculture
cause eutrophication. Silt build up in freshwater
ecosystems, caused by inappropriate agriculture,
smothers aquatic organisms. Pesticides used in
agriculture and by the health services are toxic
and interfere with breeding of mammals and birds.
Toxic metals which are produced by industry are
health and life threatening.
Sewage released into marine systems due to
inadequate sanitation will cause the diseases
mentioned above. Fertilizers used in agriculture
cause eutrophication. Oil spills from tankers
smother marine plants and animals. Plastics in
the sea causes the death of marine animals.
Pesticides used in agriculture and by the health
services also causes the death of sea life.
Solid waste is classified as hazardous
(radioactive, pesticides, medical, poisons) which
is health and life threatening; or non-hazardous
(domestic, urban, mining, industrial, scrap
metal.) which is unsightly and disposal takes up
DEALING WITH POLLUTION
In the past, most approaches to handling
pollution could be summed up by the phrase
`dilution is the solution to pollution'. However,
pollution levels have increased so much in amount
and toxicity that this approach is no longer
acceptable. An alternative approach is source
reduction, i.e. a reduction in the amount of
pollution where produced.
Point source pollution: Pollutants
are produced from a stationary location, e.g.
industrial plants, mines, and municipal sewage
Non-point source pollution:
This pollution cannot be traced to a specific
spot, and is far more difficult to monitor and
control. Common examples are veld fires, motor
vehicle emissions, fertilizer runoff, sediment
from construction and erosion, plastic packaging,
and gases from aerosol cans. Some non-point
sources can be addressed by laws, such as banning
CFCs (chlorofluorocarbons), or requiring car
manufactures to install emission controls.
principle: This means that a polluter should
bear the costs of avoiding pollution, or
remedying its effects. This principle is
difficult to apply when the source of pollution
cannot be identified, as is often the case with
atmospheric pollution. The principle can be
usefully applied following a pollution disaster,
such as an oil spill from a tanker. However, the
consumer often pays for such pollution costs. For
example, Eskom estimates that the fitting of
scrubbers (see Enviro Facts "Energy and
environment") on the chimneys of their power
stations will increase the cost of electricity by
is implemented in Europe and North America, and
is increasingly applied in South Africa.
MOVEMENT OF POLLUTION
Pollution does not stay in one place but is moved
around the world by air and water, as well as by
living organisms. Even in Antarctica, birds and
marine mammals show traces of pollutants such as
DDT and PCBs. Some pollution is deliberately
moved abroad. Companies restricted by pollution
control regulations at home, sometimes move their
plants to other less restrictive countries, as
was the case with the plant involved in the
Bhopal chemical disaster. Or while remaining at
home, they may sell products abroad, that are
classed in their own countries as too dangerous
for sale, such as banned pesticides. In some
cases hazardous waste may also be shipped abroad,
generally from industrialised countries to
developing countries willing to accept such waste
for a fee, despite the hazards (see Enviro Facts
"Toxic Waste"). When such pollutants
turn up again in the originating country, as when
food is imported that contains banned pesticides,
the process is said to be completing the `circle
WHAT YOU CAN DO
* Avoid the creation of waste (see Enviro Facts
"War on waste").
* Find out all you can about
pollution and protest loudly when you see it
* Report air pollution to the
Chief Air Pollution Control Officer (CAPCO),
Department of Health.
* Report freshwater pollution
to the Department of Water Affairs. Report marine
pollution to Department of Environment Affairs
and Tourism, Sea Fisheries Research Institute.
* Report land (solid waste)
pollution to the Department of Water Affairs.
REPORT OF THE THREE
COMMITTEES OF THE PRESIDENT'S COUNCIL ON A
NATIONAL ENVIRONMENTAL MANAGEMENT SYSTEM.
Government Printer, Cape Town, 1991.
MANAGEMENT IN SOUTH AFRICA. R. Fuggle
and M. Rabie. Juta, Cape Town, 1992.
HAZARDOUS WASTE IN
SOUTH AFRICA. VOL. 1-5, AND SUMMARY. R.
Noble (ed). Department of Environment Affairs and CSIR, 1992.
ENVIRONMENTS INTO THE 21ST CENTURY. B.
Huntley, R. Siegfried and C. Sunter. Human and
Rousseau Tafelberg, Cape Town, 1989.
J. Clarke. Southern Books, Johannesburg, 1991.
GOING GREEN: PEOPLE,
POLITICS AND THE ENVIRONMENT IN SOUTH AFRICA.
J. Cock and E. Koch (eds). Oxford University
Press, Cape Town, 1991.
All books are available from
Russel Friedman Books, PO Box 73 Halfway House
1685. Tel. 011-70022300/1.
education brochures. Available from
Eskom, address below.
"Acid rain", "Energy and
environment", "Energy options",
"Ozone", "Global warming",
"Precious water", "Toxic
waste", "Marine pollution",
"War on waste".
Environment Affairs and Tourism. P/Bag
X447, Pretoria, 0001. Tel. 012-310 3425
Department of Health.
P/Bag X828, Pretoria, 0001. Tel. 012-312 0000
Environment Affairs and Tourism: Sea Fisheries
Research Institute. P/Bag X2, Rogge Bay,
8012. Tel.021-402 3911.
Department of Water
Affairs and Forestry. P/Bag X313,
Pretoria 0001. Tel. 012-2999111.
Marketing. PO Box 1091, Johannesburg,
2000. Tel. 011-800 3398.
Institute of Waste
Management. National Office, P.O. Box
1378, Pinegowrie, 2123. Tel. 011-7891101.
South African Institute
of Ecologists. PO Box 37618, Valyland,
Fish Hoek, 7975. Tel. 021-6864419.
Water Institute of
South Africa. PO Box 1948, Parklands,
2121. Tel. 011-7284303.