What does it mean exactly? If you look up "pollution" in the dictionary you will find something like - "to destroy purity of; to contaminate, especially with man-made waste". Yes the environment, i.e. our surroundings, the place we live, is being made unclean by our own activities. The pollutants we produce not only affect our own lives but also those of other living things, the plants and animals that we share our environment with. All living things depend upon the non-living parts of the environment to survive - the land, the air and the water, and it is these 3 parts which are affected by pollution...
Land
A healthy soil is essential for life. Plants provide food for animals and human beings, and for growth and health plants need good conditions. A good soil should have plenty of humus - (decaying animal and plant remains), water, mineral salts, air and a population of living organisms, including bacteria, insects and worms. These good conditions may be ruined by...
Industrial Waste & Litter
If we're not careful, Britain could become just one big tip! Every household produces about one tonne of rubbish per year and most of it is buried in enormous landfill sites. Waste materials, some poisonous or radioactive, from factories may be dumped or buried causing danger to wildlife and humans. All the buried rubbish decomposes and can form poisonous substances which seep into the soil. The careless throwing away of unwanted things - litter - onto the streets and in the countryside by thoughtless human beings is both unsightly and dangerous to other animals.
Fertilisers & Pesticides
A growing human population over the years has meant a growing demand for food. To meet this demand, farmers have been using artificial fertilisers and chemical sprays to kill crop pests. Problems arise when these substances are over-used. Artificial fertilisers may lead to soil erosion i.e. manure used to be put on the land which contains humus and this holds the soil together; powdery artificial fertilisers do not contain humus and without it the action of the rain and wind washes or blows the valuable topsoil away. Soil erosion is a serious problem throughout the world and some areas have been turned into dustbowls and deserts.
Air
Air is a mixture of gases and without it animals and plants cannot live. Pollution is caused when harmful or poisonous substances are released or found in the air, rivers, seas, animals, plants or even our bodies. Now, we live on a strong planet with robust plants and hardy animals and humans - but there’s only so much we can take.
Did you know? Pollution is one of the main causes of asthma, which affects a whopping 1.1million children in the UK
Here are some of the causes of air pollution:
Exhaust Fumes
In Britain nearly 30 million vehicles are contributing to the pollution of the air. Petrol fumes contain carbon monoxide, carbon dioxide , nitrogen oxide, soot, oil vapour and lead - all potentially dangerous to human health. Fortunately, lead free petrol is now being used extensively and cars with catalytic converters - which remove the polluting gases (except carbon dioxide) - are beginning to be introduced. In some cities, such as Los Angeles, fog combines with the fumes to form "smog" which causes lung problems.
Industrial Smoke
In our technological world we need masses of energy for lighting, heating, cooking, transport, industry...etc. To supply this energy, fuels are burnt. When power stations burn coal, oil and gas, these fuels are not totally used up and smoke is produced This smoke contains sulphur dioxide, nitrogen oxides, carbon particles and tar.
One of the worst types of pollution that we have been producing over the last 100 years is a direct result of the gases from power stations, especially sulphur dioxide and the nitrogen oxides. These gases combine with gases such as hydrogen and oxygen to produce the dangerous acids, sulphuric acid and nitric acid. These fall to the ground as acid rain and cause damage to buildings, plants, rivers and lakes. Whole habitats around the world have been totally destroyed by acid rain.
Water
Every living thing depends on water for life. Over two thirds of the planet Earth is covered by sea water and there are also numerous freshwater habitats. Yet essential though all water is, humans continue to pollute it at an alarming rate. Here's how...
Freshwater - rivers, streams, lakes and ponds
One of the biggest threats to water purity comes from chemicals. Fields are often sprayed with pesticides and herbicides. Rain washes them off the crops into nearby streams and rivers and the bacteria which normally break down the remains of dead animals and plants in the water cannot deal with the chemicals. Animals and plants are immediately poisoned and the balance of life is seriously affected.
Artificial fertilisers containing nitrates and phosphates, "slurry" (liquid animal manure), combined with phosphates from domestic effluent such as washing powders, can also be washed into water ways. These do not poison water life directly but cause the water plants, particularly algae, to grow rapidly. The algae uses up so much oxygen that there is none left for the plants and animals. The growth also blocks out sunlight, leading to the death of underwater life. Eventually the algae itself dies, leaving a stinking, decaying mass. This problem of excess fertilisers in water is called europhication.
Factories, often built beside rivers so that water can be used, may discharge poisonous chemical waste into the water so killing the river-life.
Sewage works clean waste water from our homes and then discharge it back into the rivers. Bacteria in the filter beds digest the organic waste matter but if the water contains chemicals, such as bleach, the bacteria die and polluted water is often returned to the rivers. The water is also so depleted of oxygen that the animals cannot live in it.
Power Stations use water and when returned to the river it is often so warm that animals may die and plants grow so quickly that they may die too. Acid Rain, as described under "air pollution" is often concentrated strongly enough in rivers to kill fish.
Finally, the dumping of rubbish causes enormous damage. Streams, ponds and rivers are regularly used for dumping anything from old cans to cars. Landfill sites are the burial grounds for dangerous chemicals and metals such as cadmium and mercury from batteries. They can seep through the soil and find their way into rivers.
Microplastic beaches
Scientists have discovered that under the microscope water samples taken from beaches show tiny bits of plastic, also known as microplastic. This microplastic shouldn't be here so where has it come from?
Researchers took 18 samples from beaches around the globe including the UK, US, India and Singapore. They found that all the samples contained this tiny plastic pollutant which could be causing harm to our marine environments, and also making its way into the food chain.
Plastics such as polyester, acrylic and nylon were among the major finds across the samples, do you recognise these names? Take a look at a clothes label and you will very often find that it is made out of one of these synthetic fibres. Man-made fibres account for 68% of fibres used worldwide but how do these plastics end up on our beaches? Through our washing machines.
The researchers discovered that just one garment released up to 1,900 microplastic particles per wash! On a washing cycle when the machine is finished all the dirty water flows into sewers before being treated and flushed out to sea or in rivers. The microparticles aren't filtered out by water treatment, so make it out to sea.
These particles are swallowed by animals and can become lodged in their cells. In 2004 scientists tested plankton samples right back to the 1960s and found that the levels of microplastics had increased significantly over time. The nature of plastic is that it stays around for a long time, taking hundreds if not thousands of years to break down, and it is thought that microscopic plastics will never entirely disappear or decompose.
It is not yet known what the long term effects of this kind of pollution may be. But what we do know is that this plastic pollution will only increase as the production of synthetic fibres rises. In 2010, worldwide production of man-made fibres amounted to a whopping 53 million tonnes.
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