WATER POLLUTION

Definition "The introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in such deleterious effects as harm to living resources, hazards to human health, hindrance to marine activities, including fishing, impairment of quality for use of sea water and reduction of amenities.“ (United Nations, 1971) Water pollution almost always means that some damage has been done to an ocean, river, lake, or other water source.

Sources of Pollution Direct outfalls form factories, refineries, waste treatment plants etc.  these emit fluids directly into urban water supplies.  Indirect contaminants coming from the soil or groundwater containing contain residue coming from  human agricultural practices like fertilizers pesticides, etc.  and improperly disposed industrial wastes atmosphere via rain water entering the water supply which usually comes form human practices such as gaseous emissions from automobiles, factories, and even bakeries

Sources of Pollution Disease-causing agents: these are bacterias, viruses, protozoa, and parasitic worms that enter the sewage system and untreated waste Oxygen-demanding wastes: wastes that can be decomposed by oxygen-requiring bacteria (blue-green algae) Water-soluble inorganic pollutants: acids, salts, and toxic metals making water unfit to drink. Nutrients: water-soluble nitrates and phosphates that cause the excessive growth of algae depleting water's oxygen supply Organic compunds: soil, plastics, and pesticides Suspended sediment Water-soluble radioactive compounds

Effects on the Environment Harms the food chain: Toxins within water can harm aquatic organisms, thus breaking a link in the food chain. Flooding: The erosion of soil into waterways causes flooding, especially with heavy rainfall. Harms animals: Birds that get into oil-contaminated water die from exposure to cold water and air due to feather damage. Other animals are affected when they eat dead fish in contaminated streams. Causes algae in water: Algae grow according to how much waste is in a water source. Bacteria feed off the algae, decreasing the amount of oxygen in the water.

Effects on the Environment Suspended particles can often reduce the amount of sunlight penetrating the water, disrupting the growth of photosynthetic plants and micro-organisms. Some toxins affect the reproductive success of marine life and can therefore disrupt the community structure of an aquatic environment. The environmental damage of water pollution doesn't stop there, water pollution also increases the impact of air pollution, because the more polluted water gets the better chance there is that some of these pollutants will evaporate into air.

Acid Rain Typical rainwater has a pH of about 5 to 6. Acid rain has a pH of or below 4. During precipitation, rainwater dissolves gasses such as carbon dioxide and oxygen. When industries emit great amounts of acidifying gasses, such as sulphuric oxides and carbon monoxide, these gasses also dissolve in rainwater, which cause the pH level of rainwater to become acidic. Acid rain affects the life in the water as well as the life on land. Acid rain damages everything over a period of time because it makes the living things in the environment die.

Effects on Human Health Heavy metals from industrial processes can accumulate in nearby lakes and rivers. When ingested, this can result in birth defects and some are carcinogenic.  Industrial waste often contains many toxic compounds that damage the health of aquatic animals and those who eat them. They can cause immune suppression, reproductive failure or acute poisoning.  Suspended particles in freshwater reduces the quality of drinking water for humans and the aquatic environment for marine life. 

Effects on Human Health Microbial pollutants from sewage often result in infectious diseases that infect aquatic life and terrestrial life through drinking water. This can cause diseases such as cholera and typhoid fever and is the primary cause of infant mortality.  Sulfate particles from acid rain can cause harm the health of marine life in the rivers and lakes it contaminates, and can result in mortality. 

Effects on Human Health Exposure to polluted water can cause diarrhea, skin irritation, respiratory problems, and other diseases, depending on the pollutant that is in the water body.  Stagnant water and other untreated water provide a habitat for the mosquito and a host of other parasites and insects that cause a large number of diseases especially in the tropical regions.

Minamata Disease In Minamata, Japan, inorganic mercury was used in the industrial production of acetaldehyde, which later contaminated the nearby bay. Fish and other creatures in the sea were soon contaminated and eventually residents of this area who consumed the fish suffered from MeHg (methyl mercury) intoxication, later known as the Minamata disease.  The disease was first detected in 1956 but continued until 1968. But even after thisstopped, the bottom sediment of the polluted water contained high levels of this mercury.

Ways to Prevent or Minimize Water Pollution Conserve water. This will result to less amount of water that enters sewage systems, which is a source of contamination. Do not throw chemical substances such as paint, oil, acid, etc. in your sink or toilet. Do not litter in bodies of water (i.e. oceans, lakes, rivers, etc.). Use natural pesticides and fertilizers. The chemical ones seep into ground water and runs off to bigger water sources, thus polluting the water.

Ways to Prevent or Minimize Water Pollution Use environmentally-friendly household products instead of products that contain chemicals. Example: instead of bleach, use vinegar. Chemical household products tend to go down the drain and mix with the water in the sewage systems. Regularly check and fix your septic system. Poorly conditioned systems contaminate the water it contains, which pollute nearby water sources when released.

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