The environmental degradation continues to accelerate. As a result of our new technologies we pollute rivers, lakes, oceans, the sky; we lose soil and destroy natural habitats. We are in an environmental crisis because human activities affect the nature.

Nowadays people understand how important it is to solve the environmental problems that endanger people’s lives. The most serious environmental problems are:

-  water pollution;

-  air pollution;

-  soil pollution;

-  destruction of wildlife.

Water Pollution

One of the most urgent human problems in the world today is the shortage of clean water.

Water pollution comes from many different sources (acid rain, industrial waste, sewage) and can affect many different things. For example, Lake Baikal in Russia is one of the largest lakes in the world. It contains a rich variety of animals and plants, including 1300 rare species that do not exist anywhere else in the world. But they are being destroyed by the massive volumes of industrial influent which pour into the lake every day.

The effects of water pollution pose a serious threat to society today and in the future.

Many people today dump their garbage into streams, lakes, rivers and oceans. Some examples of this garbage are cans, paper, furniture and other household products. When people dump cleaning products to the ecosystem they are endangering its inhabitants. When plastic is dumped in lakes, ducks are at risk because they might be strangled and when dumped in the ocean - dolphins might be killed. Aluminum cans can cut the animals and fish.

Many factories have pipes that drop chemicals into rivers or streams. These chemicals can damage aquatic life as they are carried by downstream. Furthermore, the added chemicals can warm the river, which decreases the amount of oxygen that the fish need to live.

When oil is spilled into the water, the effects on the ecosystem and its components are devastating. Some animals, such as birds, mammals and fish can be killed if they ingest oil. Many may die from eating oil contaminated prey. Birds may die if the oil coats their feathers. They can neither fly nor stay warm. Furthermore, when oil coats the feathers they can become sick and die. Oil and antifreeze can cause the water to have а bad odor and leave а sticky film on the surface of water that kills animals and fish. Oil is one of the most devastating pollutants of water.

Water from rain runs down the slopes of the land which may include farm areas that use fertilizers, pesticides and other farming chemicals. After that they travel down into the rivers, lakes or oceans. Fertilizers and some chemicals may cause plants to grow quicker. With the growth of more plants, more bacteria will grow (bacteria eat dead plants). Bacteria need oxygen to survive and if there are more bacteria in the river than normal, there is less oxygen for fish and some of them may die. Pesticides are toxic substances widely used in farming and forestry but they are concentrated as they go up the food chain. They are not excreted by the fish or animal absorbing it, they accumulate and are passed to the higher animal that eats them.

Other chemicals besides farming chemicals affect humans as well. Nitrates in drinking water can cause diseases to infants that might cause them death. Cadmium can be absorbed by crops, and if people ingest this in sufficiently large quantities it can cause diarrhea disorders, liver and kidney damage. The culprit is suspected to be inorganic substances such as mercury, arsenic and lead.