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Pollution v • d • e

Air pollution

Acid rain • Air Quality Index • Atmospheric dispersion modeling • Chlorofluorocarbon • Global dimming • Global warming • Haze • Indoor air quality • Ozone depletion • Particulate • Smog

Water pollution

Eutrophication • Hypoxia • Marine pollution • Ocean acidification • Oil spill • Ship pollution • Surface runoff • Thermal pollution • Wastewater • Waterborne diseases • Water quality • Water stagnation

Soil contamination

Bioremediation • Herbicide • Pesticide • Soil Guideline Values (SGVs)

Radioactive contamination

Actinides in the environment • Environmental radioactivity • Fission product • Nuclear fallout • Plutonium in the environment • Radiation poisoning • Radium in the environment • Uranium in the environment

Other types of pollution

Invasive species • Light pollution • Noise pollution • Radio spectrum pollution • Visual pollution

Inter-government treaties

Montreal Protocol • Nitrogen Oxide Protocol • Kyoto Protocol • CLRTAP

Major organizations

DEFRA • EPA • Global Atmosphere Watch • Greenpeace • National Ambient Air Quality Standards

Related topics

Natural environment

Water stagnation occurs when water stops flowing. Stagnant water can be a major environmental hazard.

Contents 1 Dangers 2 Causes and prevention 3 Life that may thrive in stagnant water 3.1 Bacteria 3.2 Fish 3.3 Insects 3.4 Other 4 Miscellanea 5 See also

Malaria and dengue are among the main dangers of stagnant water, which can become a breeding ground for the mosquitoes that transmit these diseases.

Stagnant water can be dangerous for drinking because it provides a better incubator (than running water) for many kinds of bacteria, and other parasites.

Stagnant water may be classified into the following basic, although overlapping, types:

• Water body stagnation: stagnation in lakes, lagoons, rivers, etc.
• Surface and ground water stagnation
• Trapped water stagnation. The water may be trapped in human artifacts (discarded cans, plant pots, tires, dug-outs, roofs, etc.), as well as in natural containers, such as hollow tree trunks, leaf sheaths, etc.

To avoid ground and surface water stagnation, drainage of surface and subsoil is advised. Areas with a shallow water table are more susceptible to ground water stagnation due to the lower availability of natural soil drainage.

Excessive watering may cause ground or surface water stagnation.

Some plants prefer flowing water, while others, such as lotuses, prefer stagnant water.

Various anaerobic bacteria are commonly found in stagnant water.

• Denitrifying bacteria
• Purple bacteria (both sulfur and non-sulfur)
• Leptospira

• Northern snakehead fish
• Siamese fighting fish
• Pygmy gourami
• Spotted barb
• Lepisosteidae (gar)
• Walking catfish

Stagnant water is the favorite breeding ground for a number of insects.

• Mosquito larvae
• Fly maggots
• Dragonfly nymphs
• Nepidae (water scorpions)

• A number of species of frogs prefer stagnant water.
• Algae
• Biofilm
• Some species of turtles
  • Mata mata

Pools of stagnant water have historically been used in the processing of hemp and some other fiber crops, as well as of linden bark used for making bast shoes. Several weeks of soaking makes bast easily separable due to bacterial and fermentative processes.

• Water pollution