Subskill: Reading Comprehension
Concept: Cause and Effect
Grade Level: Middle Elementary
All living things need water to stay alive, which is why water is our most precious natural resource. For this reason, it is important to learn about the causes of water pollution.
Water pollution is simply any harmful thing that is added to water. There are many causes of water pollution, but you cannot always see what is polluting it. Water can look clear, yet still be unsafe. It can be polluted by microscopic organisms, which are so tiny, they can only be seen with a microscope. These organisms are sometimes contagious and can make us sick. One cause of microscopic organisms in water is sewage from pipes.
Another major cause of water pollution is the fertilizers farmers use to make their crops grow fast and the pesticides they use to kill bugs and rodents. When it rains, these fertilizers and pesticides can wash off into waterways.
In addition, wastewater from factories contains harmful chemicals that can be poisonous to marine life. This wastewater is also very hot, and when it is pumped into waterways, it has the effect of heating up the temperature of the water. Many plants and animals cannot survive if the temperature of the water rises due to lack of oxygen.
Litter also pollutes waterways. When not disposed of properly, garbage shows up on the shorelines of beaches and can also be harmful to marine animals. Moreover, anything with a sharp edge can cut a mammal or fish. Marine animals are also known to mistake garbage for food.
Petroleum companies ship their oil all over the world in large supertankers, but accidents do happen. An important cause of water pollution and a great loss of marine life along shorelines is accidental oil spills by these large supertankers.
Here are some questions to ask after listening to the article:
What is one cause of water pollution?
What is a cause of microscopic organisms in water?
What is a harmful effect of litter in waterways?
What is the effect of very hot wastewater pumped into waterways?