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People and the Water Systems. Water Pollution 1950s USA (video). Why Some Beaches Get Closed?. Polluted water due to: Industrial waste Farming fertiliser Garbage dumping sites Oil spill accidents. Microorganisms. Water contains small amounts of microorganisms
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People and the Water Systems Water Pollution 1950s USA (video)
Why Some Beaches Get Closed? • Polluted water due to: • Industrial waste • Farming fertiliser • Garbage dumping sites • Oil spill accidents
Microorganisms • Water contains small amounts of microorganisms • When concentration is too high they create health problems • A common microorganism is coliform bacteria
The role of the temperature • Warm temperature creates good conditions for bacteria to multiply • Most common problems • Digesting system • Nausea • Vomiting • Diarrhea • Skin problems • Rash • Infections
Humans and Waterways • People enjoy the beauty of waterways • Some activities may create problems to environment • Gas-powered boats • Litter in beaches and campsites
Acid Rain • In many cases the air is polluted from toxins discharged in it • Such pollutants might be sulfur, dioxide and nitric oxide • Acid precipitation occurs when water vapor reacts with airborne pollutants • The resulting sulfuric acid and nitric acid fall back into Earth together with precipitation
Reading • Science & Technology 8 p. 218-219 • Answer the questions: What health risks are associated with the presence of coliform bacteria? Why are populations of many lake bacteria higher in the summer? • Homework: Monitoring water use at Home