The environment means surroundings in which people, animals and plants develop and exist.
Ecology is a branch of biology which investigates relationships between living beings and tnd their surroundings,environment.
The most serious ecological problems of today are the pollution of air, water and soil, the global warming, the greenhouse effect,acid rains, breaking of the ozone layer, destruction of tropical rainforests, extinction of animal species and natural disasters such as floods, draughts, hurricanes.

Pollution is damage to the surroundings. We know three main forms of pollution-air, water, land pollution.

AIR POLLUTION

It is the biggest problem in the town and cities with developed industry. The most harmful emissions are smoke e.g. from factories, dust, car exhauts. Smoke is mostly formed when fossil fuels are burnt.The growing number of cars on roads and highways contribute much to the air pollution. Factories produce large quantities of carbon dioxide, lead poisons, sulphur and nitrogen compouds which get into the air.This is one of the main causes of the acid rain
Acid rain-the harmful substances (sulphur dioxide, nitrogen oxide) in the air mix with water vapour in the atmosphere and form dangerous acids in the clouds. They later fall down as acid rain. Acid rain kills trees, makes soil infertile, destroys life in lakes and rivers, destroys buildings and causes quicker corrosion of some materials.
There are also other gases which contribute to another serious ecological problem, the greenhouse effect, which causes serious climatic changes.

Greenhouse effect-it is caused by harmful gases which are so called greenhouse gases.The most known of them are CFCs ( from aerosols and refrigerators ) and carbon dioxide. These gases stay in the atmosphere and the heat from the sun can´t get back into the space so it stays in the Earth´s atmosphere. The earth behaves like a greenhouse. That´s why the Earth´s temperature is rising and is called the global warming.
Global warming- the temperature on the Earth has gradually been gradually rising in the last decades. It is caused by the changes in the atmosphere, mostly by the air pollution. The temperature is rising, the ice caps on the poles are melting and thus sea level is rising.This means that in the future coastal areas will be flooded. Floods are not the only consequence of the global warming. On the other hand, thetre are severe draughts which lead to famine and many people are dying of starvation.
Ozone hole- Ozone forms a layer in the upper atmophere. It protects life on Earth from harmful ultraviolet radiation from the sun rays, which is the main cause of skin cancer. But there appeared a hole in the ozone layer whis still getting larger and larger and this harmful radiation endangeres life on Earth.The main danger for the ozone layer are CFCs from aerosols and refrigerators.

How can the problems of air pollution be solved?
People should try alternative sources of energy, such as solar, water, wind, geothermal, tidal or burn smokeless fuels.
We should reduce road traffic, use more railways or public transportation.
Tree planting is also important because trees are the lungs of our planet. They breath in harmul carbon dioxide and give out life sustaining oxygen which is necesarry for all living creatures in the world.
Cars shoul have catalytic converters and use unleaded petrol.

WATER POLLUTION

Factories directly increase water pollution. Many of them are buit near rivers into which they put their chemical waste. Another polluters are households which put sewage into water, then farmers with their pesticides or fertilizers, waste disposal sites and also ships. Water pollution can have serious effect on our health as well as on life in rivers or other animals which drink poisonous water or eat plants which are poisoned.

How can we solve the problems of water pollution?
We should lower the factory waste discharges into water, we should build more sewage treatment plants, we should develop enviromentally friendly pesticides and people shouldn´t clean their cars near rivers

SOIL POLLUTION

Soil is mostly contaminated as a result of industrial waste and domestic rubbish.Rubbish is disposed on landfills.Landfil areas contaminate underground water.Solid waste is a big problem .

Before we put waste on the landfil site we shoul do something to reduce it. There are three main steps how to make our surroundings cleaner and healthier- reduce, reuse, recycle. first of all we shoul try to reduce the amount of solid waste in a way that we will use less one-time-use items.

Recycling is a proces when we make the used material usable again. First of all we sould sort out the rubbish.We have bottle containers, can containers, plastic containers and paper containers.
Domestic rubbish should be sorted out too. Kitchen garbage and garden waste of organic origin can be composted and turned into fertilizer

Reuse-people shoul reuse as many materials as they can or at least sort them out for recycling
People shouldn´t throw litter in the streets or in the countryside.

sewage treatment plant-čistička odpadových vôd
sewage-kanalizačné splašky
factory waste discharge-vypúšťanie odpadu z tovární