Cool, Clear Water
The lake in the picture above looks clean and healthy. A person may be tempted to sit down by the bank and have a cool drink of water. However, this is not a good idea. You don’t know what is in that water. There are a number of pollutants that could be present, both from natural processes and from human contamination.
Why It Matters
- Water is a precious commodity, one on which our lives are based. Our bodies need fresh water every day to maintain proper functioning. Unfortunately, much of our water supply cannot be used. A variety of pollutants are dissolved in the water, including toxic metals, pesticides, and fertilizers. Some affect the safety of water directly, while others promote growth of algae and other materials that deplete the oxygen supply and increase the loss of fish and other aquatic creatures.
- Cyanide ion (CN-) can be a major contaminant in areas where there is a large amount of industrial activity. This water-soluble pollutant comes mainly from metal refining and finishing industries, as well as organic chemical manufacturing plants. Exposure to cyanide can produce rapid breathing and tremors short-term, and significant nerve damage long-term.
- Lead contamination comes mainly from plumbing, not from pollution of natural water supplies. Older houses (before 1986) have lead plumbing which can leach lead into the water system. In children, the chief effects are delays in development and impaired learning.
- Oil spills are a major contaminant problem in the oceans. Either through leakage or damage to a ship. there have been several large oil spills over the years. These materials are not water-soluble, so remain on the water surface where they contaminate both plant and animal life. Oil clean-up involves a variety of approaches, including physical trapping, treatment with dispersants to make the materials more water-soluble, and bacterial degradation.
- Watch a video about an oil spill at the link below:
Show What You Know
Use the links below to learn more about water pollution. Then answer the following questions.
- What is one example of natural water pollution?
- How do car oil and antifreeze contribute to pollution?
- What percentage of U.S. rivers and streams are too dangerous for fishing or drinking?
- What fraction of the wells in one survey were found to be polluted with pesticides?
- What are factors that influence pesticide contamination of water supplies?