Talking About Water
Pollution:
Water pollution is when waste,
chemicals, or other particles cause a body of water (i.e. rivers, oceans, lakes) to become harmful
to the fish and animals that need the water to survive. Water pollution
can disrupt and negatively impact nature's water
cycle as well.
A
lot of water pollution comes from human activity. Some human causes include
sewage, pesticides and fertilizers from farms, waste water and chemicals from
factories, silt from construction sites, and trash from people littering.
There
are many sources of water pollution. Here are a few of the major causes:
- Sewage - Even today sewage is flushed directly into streams and rivers in many areas around the world. Sewage can introduce harmful bacteria that can make people and animals very sick.
- Farm animal waste - Waste from large herds of farm animals such as pigs and cows can get into the water supply from the runoff of rain and large storms.
- Pesticides and herbicides - Pesticides are often sprayed on crops to kill bugs and herbicides are sprayed to kill weeds. These strong chemicals can get into the water through runoff of rain storms. They can also contaminate rivers and lakes through accidental spills.
- Construction, floods, and storms - Silt from construction, earthquakes, floods, and storms can lower the oxygen content in the water and suffocate fish.
- Factories - Factories often use a lot of water to process chemicals, keep engines cool, and for washing things away. The used waste water is sometimes dumped into rivers or the ocean. It can be full of pollutants.
(Extracted from http://www.ducksters.com/science/environment/water_pollution.php
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