Water Pollution Issues Globally

Water Pollution in Less Developed Countries

• Half of the world's 500 major rivers are polluted by untreated sewage and industrial waste.
• Water is often used for human activities despite pollution.

Water Pollution in More Developed Countries

• Water pollution control laws were introduced in the 1970s.
• Successful water clean-up efforts are evidenced by cases such as the Ohio River (US) and Thames River (Great Britain).
• Industrial and mining activities contribute to contamination by toxic inorganic and organic chemicals.

The Ganges River (India)

• Industrial and raw sewage are major pollutants.
• Metal contamination leads to diseases and illnesses.

The Citarum River (Jakarta, Indonesia)

• Trash is the primary pollutant.
• River workers move trash away from areas near the river.

The Yellow River (China)

• Respiratory illnesses and cancers are linked to polluted water.

The Sarno River (Italy)

• Industrial and agricultural activities pollute the river.
• Liver cancer is a result of pollution.

The Buriganga River (Bangladesh)

• Dye discharge contaminates the river, impacting human health by affecting smell, lungs, kidneys, and causing premature deaths.
• Industrial activity is another source of pollution.

The Great Lakes

• Cultural eutrophication is a concern, stemming from nitrates and phosphates from various sources like farms, feedlots, streets, parking lots, and fertilized lawns.
• Mining sites and sewage plants contribute further to contamination.

Cultural Eutrophication

• Excessive nutrients (nitrates and phosphates) from human activities cause algal blooms.
• Fertilizers, farms, and sewage contribute to the problem.

During Hot Weather/Droughts

• Algal blooms and increased bacteria (both aerobic and anaerobic) occur due to high nutrient presence during hot weather or drought.

Preventing/Reducing Cultural Eutrophication

• Removing nitrates and phosphates is crucial.
• Diverting lake water is one possible measure.
• Cleaning up lakes and removing excess weeds through the use of herbicides and algaecides.
• Pumping air into lakes to reduce stagnation.

1960s-1970s Pollution Control Programs

• Control programs like the Canada-US Great Lakes pollution control program reduced algal blooms and increased fishing catches.
• However, existing issues of raw sewage and pollution from pesticides/fertilizers remain.

Major Water Pollutants

• Excessive or improper handling of nutrient pollution, which enters the rivers from different sources.
• Heavy metal pollution from industrial waste.
• Pesticides and fertilizers which enter the water from industrial and agricultural runoff.
• Improper waste disposal that causes the entry of dangerous bacteria into water sources.

Water Pollution Effects

• Water pollution leads to various infectious diseases, including typhoid and guinea-worm disease, and is a significant cause of death, mostly among children under five years of age.
• Polluted water can also lead to cesspool leakage and overflow of bacteria into water sources, such as the case of Pfiesteria piscicida which causes disease in aquatic organisms.

Nuclear Pollution

• Thermal pollution occurs from industries that alter the ecological balance of water bodies.
• Heat stress and changes to fish habits result from this type of pollution.
• Sediments affect aquatic life as well.
• Heavy metals like lead, mercury, chromium, cadmium, and are toxic.

Heavy Metals

• Methyl mercury is toxic to most living organisms.
• Minamata Bay, Japan, experienced mercury poisoning as a result of industrial/chemical pollution in 1938, and ecological damage began in 1950.
• Lead poisoning causes health issues, including headaches, irritability, reduced sensations, and aggressive behavior.

Pollution Control

• Scientific authorities have set maximum contaminant levels for pollutants that affect human health.
• Water-polluting companies may actively seek to ignore or weaken such laws.

Water Purification

• Several methods like reservoirs, purification plants, treatment of sewer water, plastic exposure to sunlight (UV) for disinfection, and use of chemicals (chlorine and iron sulfate) are used to purify water.

Bottled Water

• Bottled water can be expensive.
• The U.S. and Canada have relatively clean drinking water.
• Bottled water is less regulated than tap water.
• Bottled water use can result in environmental problems.