pollution is harmful to human beings. polluted water causes many kinds of diseases such as diarrhea, enteritis, etc. and sometimes these diseases even take man’s life. dirty air or air-borne garbage causes stinging eyes and running nose. pollutants are destructive. they cause runs in nylon stockings and crack rubber tires and they eat away at stone and rust iron.

　　measures have been taken to control pollution. in recent years, legislative steps have been introduced to control pollution. rivers are being cleaned. air is purified, and pollutants are being trapped before they are poured out of chimneys.

　　however, pollution problems have not been completely solved. pesticides are widely used almost everywhere. they pollute soil, water and food. they have the power to make our streams fishless and our gardens and woodlands silent and birdless. some factories are still using air as a dumping place for wastes. some lakes are still dirty. quite a few chimneys are still pouring smoke into air and noise pollution remains serious.