Freshwater Pollutants

Freshwater can fall under two categories, lentic water and lotic water. Lentic water refers to a body of still water, such as a lake. Lotic water refers to actively moving water such as a river or stream. Freshwater sources can become polluted due to human contamination. As a result, humans, animals and plants can become threatened by the pollution. It is also possible for habitats to be destroyed due to pollution of freshwater biomes. A biome is a geographical area consisting of plants and animals.

Metals

• Heavy metals are contributors of pollution.

  Metals in freshwater systems are one of the biggest contributors of pollution. Metals are discharged into freshwater via industrial plants, crop fields, lawn and street discharge, and from mines. Metals include cadmium, arsenic, lead, copper and mercury. Metals that enter freshwater can remain sedentary for years. As a result, the metals become non-biodegradable. When an animal ingests a metal, the toxin is stored in the animal's fat. If a human consumes a contaminated animal such as a fish, the toxin can be released to the human. According to the U.S. Geological Survey, 33 states have issued an advisory warning for fish consumption due to an increased prevalence of mercury in fish.

Detergents

• Detergents can lead to the growth of algae.

  Detergents refer to products used for industrial and domestic purposes. Such detergents can be soaps or detergents used when washing your car. According to Lenntech Water Treatment Solutions, if detergents appear in freshwater, aquatic life becomes threatened. The external mucous layer responsible for protecting fish from harmful parasites can be compromised. Organisms may have difficulty in breeding, and detergent can also kill fish eggs. Phosphates contained in detergents can cause algae blooms. Algae blooms can deplete the oxygen necessary to sustain aquatic life.

Organic Pollutants

• Organic pollution can cause difficulty for sustained life in freshwaters.

  Organic pollutants include raw or treated sewage, urban run-off, farm waste, as well as other organic compounds. Organic pollutants are troublesome because it requires massive amounts of oxygen to breakdown complex organic molecules into simpler molecules. This breakdown lowers available oxygen in the freshwater, resulting in turbidity, or suspended solids in water.

Other Pollutants

• Aquatic life suffers from freshwater pollution.

  Other forms of freshwater pollutants include chlorine, pesticides, radionuclides, acids and alkalis. Chlorine and pesticides are not only toxic, but carcinogenic. Fish ingesting these contaminants are ingested by animals that then are ingested by humans. Radionuclides are found in rocks and soils, which then seep into freshwater. Acids and alkalis found in freshwater are a result of acid rain. Radionuclides, acids and alkalis kill fish, make species incapable of breeding and damage developing fish.