Water is a necessity to life on earth. All organisms contain it, some drink it, and others inhabit it. Plants and animals require water that is moderately pure, and they cannot survive if their water is affluent with toxic chemicals and/or harmful microorganisms. If severe, water pollution can kill large numbers of fish, birds, and other animals, in some cases killing all members of a species in an affected area. Water pollution is not only hazardous to water-bond animals it also poses as threat to humans as well.
The majority of water pollution occurs when people overload the water environment with wastes. It’s defined as contamination of streams, lakes, underground water, bays or oceans by substances harmful to living things. Such things as oil spills, boat fumes, and dumping of trash into the oceans, lakes, and rivers are just a few of the major contributors to water pollution. Throughout the past century water pollution has become a very real problem and solution must be found.
First of all, Water pollution presents problems to humans in a few ways. Water pollution makes streams, lakes, and coastal waters unpleasant to look at, to smell, and to swim in, as well as preventing us from drinking it without filtration. Fish and shellfish harvested from polluted waters may be unsafe to eat. People who ingest polluted water can become ill and if they’re exposed for a long time, may develop cancers, or have children with birth defects.
There are two types of water pollution; point source and non-point source. Point sources of pollution occur when harmful substances are put directly into a body of water (such as an oil spill). A non-point source is when pollutants enter the water indirectly through environmental changes (like when fertilizer is carried into a stream by rain).
The major water pollutants are chemical, biological, and physical materials that lessen the water quality. These pollutants can be separated into seven
different classes: Petroleum products, pesticides and herbicides, heavy metals, hazardous materials, excess organic matter, sediment, and finally thermal pollution.
The first category is petroleum products. Petroleum products include oil and chemicals from oil are used for fuel, lubrication, plastics manufacturing, and many other purposes. The petroleum products get into water by accidental spills from ships, tanker trucks, and leaky underground storage tanks. Many petroleum products are poisonous if ingested by animals and spilled oil damages the feathers of birds and the fur of animals, often causing numerous deaths among these birds, furred animals, as well as fish.
The second category that pollutants can be classified as is pesticides and herbicides. These include chemicals used to kill unwanted animals and plants. An example of this may be something used to keep certain bugs off of fruits or vegetables. These pollutants may be carried into streams by rainwater. If the chemicals in these herbicides and pesticides are not biodegradable they can remain dangerous for a long period of time. When an animal eats a plant that has been treated with certain non-biodegradable chemicals, the chemicals are absorbed into their tissues or the organs. When other animals feed on a contaminated animal, the chemicals are passed up to them. As it goes up through the food chain, the chemical becomes more harmful, so animals at the top of the food chains may suffer cancers, reproductive problems, and death. This can be a very serious problem for many species of animals.
The herbicides and pesticides found in some polluted waters don’t simple pose a problem to animals; they can also be harmful to humans. More than 14 million Americans drink water contaminated by pesticides, and the EPA estimates that ten percent of wells contain pesticides. These Nitrates can cause a lethal form of anemia called blue baby syndrome in infants. Also there are many other humans that have allergies to these chemicals, and can cause health problems if enough of the contaminated water is digested.
Other chemicals that are a problem in the pollution of water are heavy metals. Heavy metals, such as copper, lead, mercury, and selenium, get into the water from industries, automobile exhaust, mines, and natural soil. Heavy metals also become more harmful as they follow the food chain. When they reach high levels in the body, they can be immediately poisonous, or can result in long-term health problems. They can sometimes cause diarrhea and, over time, liver and kidney damage. Children exposed to lead in water can suffer mental retardation. Fish that have been exposed to mercury can be extremely poisonous to humans if they eat the fish.
The fourth classification that is known to pollute waters is hazardous materials. Included in this class are chemical wastes that are toxic, reactive, corrosive, or ignitable. If not treated or stored properly, they can pollute water supplies. Such as in other categories once the hazardous wastes reach one part of the food chain they can be passed on to the animals that depend on them for food.
The fifth leading cause of water pollution is excess organic matter. Some examples of excess organic matter are fertilizers and other nutrients used to promote plant growth on farms and in gardens that may fine their way into water. At first the nutrients will help the plants and algae in the water grow, but when they die and settle underwater, microorganisms decompose them, while decomposing them the microorganisms take in oxygen that is dissolved in the water. The oxygen levels in the water may drop so low that fish and other oxygen-dependent animals in the water suffocate, and die, this happens mostly in the Midwest and other such places where there are vast amounts of farm land.
Yet another principal cause of the pollution of water is sediment. Sediment is soil particles carried to a stream bed, lake, or ocean, if in large amounts, can also be a pollutant. Soil erosion can damage a stream or lake by adding too much nutrient matter. Sedimentation can also cover stream bed gravel where many fish lay their eggs. Therefore, this can greatly decrease the population of fish in future generations. This is one of the many reasons that soil erosion is trying to be prevented today.
The final cause of water pollution, which is often overlooked, is known as Thermal water pollution. Thermal pollution takes place when water is taken from rivers, lakes, or the ocean to be used in factories and power plants. This water is usually returned to the source much warmer than when it was taken. Even a small temperature change in a body of water can drive away the fish and other species that were usually inhabited that particular region, and in conjunction attract other species in place of them. This develops unwanted ecosystems in areas where they should not be. Thermal pollution can speed up the biological processes in plants and animals and/or lower the oxygen level in the water. Fish and other wildlife near the discharge source, may die.
So as you can see, water pollution is a very serious problem it is responsible for dramatic decreases of fish and wildlife populations in our, rivers, lakes, and oceans. Water pollutants should also be held accountable for many cases of food poisoning, especially experience in seafood. In order to solve this problem we need to learn about ways for disposing harmful household wastes so they don’t end up in sewage treatment plants or landfills. In our yards, we should determine whether or not we need to add nutrients before fertilizers are applied, and look for alternatives where fertilizers may run off into surface waters. We need to preserve existing trees and plant new trees and shrubs to help prevent soil erosion. Around the house we should we need to keep litter, pet waste, leaves, and grass clippings out of gutters and storm drains, and buy as many heavily packaged foods, certain boxes, cartons, bottles, etc that are made with polluting dyes.
On a more widespread note, we must be much more careful about the types of pesticides we use, how we transport oil and other harmful materials, and work as hard as we can to prevent soil erosion and excess organic matter. If everyone works together to prevent water pollution this problem can be decreased drastically, if not eliminated. We all depend on water as a part of everyday life, we simply need to make sure that we as humans don’t take this for granted, and take every step possible to keep the waters on this Earth as clean as possible.
Water Pollution, http://www.umich.edu/~gs265/society/waterpollution.htm.
Water Pollution General, http://members.tripod.com/water_pollution_hk/newpage2.htm.
Water Pollution, http://www.soton.ac.uk/~engenvir/environment/water/water.html.
Sources of Water Pollution, http://www.soest.hawaii.edu/GG/ASK/waterpol3.html.