ACID RAINS

Дата добавления: 2014-10-24 | Просмотров: 1501

Every year more and more plants and animals disap­pear never to be seen again. Strangely, it is the most in­telligent but most thoughtless animal that is causing most of the problems — man. Nature is very carefully balanced and if this balance is disturbed, animals can disappear alarmingly fast. Every day, thousands of spe­cies of animals draw closer to extinction.

In many lakes fish are dying. Fishermen are worried because every year there are fewer fish and some lakes have no fish at all. Scientists are beginning to get wor­ried too. What is killing the fish?

The problem is acid rain. Acid rain is a kind of air pol­lution. It is caused by factories that burn coal or oil or gas. These factories send smoke high into the air. The wind often carries the smoke far from the factories. Some of the harmful substances in the smoke may come down with the rain hundreds of miles away.

The rain in many places isn't natural and clean any more. It's full of acid chemicals. When it falls in lakes, it changes them too. The lakes become more acidic. Acid water is like vinegar or lemon juice. It hurts when it gets in your eyes. It also kills the plants and animals that usu­ally live in lake water. That is why the fish are dying in lakes.

But dead fish may be just the beginning of the prob­lem. Scientists are finding other effects of acid rain. In

some large areas trees are dying. Not just one tree here and there, but whole forests. At first scientists couldn't understand why. There were no bugs or diseases in these trees. The weather was not dry. But now they think that the rain was the cause. Acid rain is making the earth more acidic in these areas. Some kinds of trees cannot live in the soil that is very acidic.