Pollution is when various contaminants are introduced into a natural environment that causes instability, disorder, harm or discomfort to an ecosystem.
Pollution can take a number of forms including:
· Air pollution - comes from both natural and man-made sources. Motor vehicle emissions are one of the leading causes, but other principal pollution sources include chemical plants, coal-fired power plants, oil refineries, petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms, PVC factories, metal production factories, plastic factories and other heavy industry.
· Odour pollution - related to air pollution and although not necessarily harmful, is environmentally most unpleasant. Sources can include industrial processes and landfill sites.
· Soil pollution - when chemicals or other substances are released into the ground deliberately, accidentally or by underground leakage. These can include hydrocarbons, herbicides, pesticides, chlorinated hydrocarbons and heavy metals such as chromium and cadmium from batteries.
· Thermal pollution - temperature change to natural water by, for instance, the addition of water used in the cooling of power plants.
· Noise pollution - chiefly associated with transport and heavy industry. This will include roadway noise, aircraft noise, industrial noise and can also include high intensity sonar.
· Visual pollution - can include a proliferation of overhead power lines, advertising signboards alongside major roads, scarred landscapes following opencast mining and open storage of scrap metal and waste. There is also a strong body of opinion that considers wind farms to be a form of visual pollution.
· Water pollution - the discharge of wastewater, intentionally or otherwise, from commercial, industrial premises or industrial processes into surface water. Water pollution can include untreated sewage plus the chemical contaminants used to treat sewage such as chlorine; runoff from surface water that can include chemical fertilisers and pesticides, plus urban pollutants; and general leaching from waste disposal. One large scale example of water pollution occurs with the process of hydraulic fracturing (fracking or hydrofracking), a process used to extract natural gas reserves from shale that requires large quantities of water. Studies on the hydrofracking process have found water pollution issues, raising health and other concerns.
Pollution is not always the result of human action; it can also be the consequence of natural disasters such as hurricanes and tornadoes, other severe storms and earthquakes and volcanic eruptions. These can all cause pollution that often results in drinking water supplies being contaminated by sewage and petrochemical spills from ruptured tanks from boats, automobiles or storage tanks.
This was tragically illustrated in March 2011 when an unprecedented earthquake and tsunami in Japan caused considerable environmental damage, loss of life and pollution, including the release of potentially hazardous nuclear contaminants.
Pollution is acknowledged as being a grave risk to many organisms. Human health can be affected in a number of ways. Polluted air can cause respiratory disease, cardiovascular disease, throat inflammation, chest pains and general congestion. Older people are at most serious risk, especially those with heart or lung disorders, but children and infants are also particularly vulnerable
It is reported that in China alone around 650,000 people die each year as a result of air pollution and the number who die in India is well over half a million. It is thought that even in the US the figure could top 50,000.
Is estimated that worldwide, contaminated drinking water kills around 14,000 people each day. This is mainly from untreated sewage. In October 2010 the UN Human Rights Council affirmed that clean, safe drinking water is a binding and universal human right, yet it is estimated that almost 900 million people are still without access to clean drinking water and more than 2.6 billion people do not have access to basic sanitation.
Pollution is largely the result of waste created by an industrialised society. At one time there was very little waste to dispose of but the world has now moved to a state where there is so much waste that its disposal must be controlled, otherwise environmental pollution will be the inevitable result.
The waste products of the world might come from consumption, heating, agriculture, mining, manufacturing, fossil fuel extraction, transportation, or some other human activity and without some form of control, they will degrade the environment as they accumulate or disperse.
The logical aim must be to minimise waste and prevent pollution rather control the pollution once it has occurred.
Certainly in the developed world conscious efforts are now being made to minimise waste. Many procedures for recycling waste have been developed in recent years. Awareness of the effects of pollution has led to stricter regulations with respect to automobile, shipping and industrial emissions. Considerable progress has been made in the sustainable transport field, with the design and development of emission-free vehicles.
One area where progress continues to be slow is with respect to pollution and the link to climate change and global warming. Our industrialised world releases large quantities of gas into the Earth's atmosphere. This is often known as greenhouse gas, because it has a similar effect to a greenhouse in that it forms a layer around the Earth that prevents the heat from the sun from being reflected back into space. The result is that the Earth heats up, rather in the manner of the air inside a greenhouse.
One of the effects of the release of these gases into the atmosphere is that they cause an increase in carbon dioxide in the oceans. Corals can undergo a process known as bleaching causing the reefs to perish. Since the coral reefs are the home of scores of other creatures that rely on the reefs for food, they also die, resulting in the destruction of entire ecosystems.
Other predicted outcomes are the melting of glaciers and ice caps causing rises in the level of oceans, which could seriously affect coastal ecosystems. Sulphur dioxide from factory emissions can mix with hot air and cause destructive acid rain, adding to the destruction of the world's rainforests.
Plastic pollution is also a serious issue in some of the world's oceans; ocean currents mean this plastic detritus cumulates together forming large garbage patches. The largest of these patches, approximately as large as Texas, is located in the Northern Pacific Ocean, named the Pacific Gyre or The Great Garbage Patch.
Global warming has a major influence on world pollution and has been described as a ticking active bomb. It might seem that there is no stopping its onslaught and although in some respects this might be partly true, it is certainly possible to slow the process down. Time is fairly short, but if the nations of the world took a united stand to cut greenhouse emissions this would certainly be a major step in the right direction.
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