Quick FactAccording to the World Water Development Report, 2012, up to 90 % of wastewater in developing countries flows untreated into rivers, lakes and highly productive coastal zones, threatening health, food security and access to safe drinking and bathing water.
The addition of harmful or toxic material that results in degradation of the quality of water is termed as water pollution. Today, it has become a global concern, with an annual average of 5 million people dying because of water-related problems. The most abundant resource (water) on our planet Earth has been adulterated by mankind to a great extent for various personal gains.
The pollutants are effluent outputs from refineries, factories, waste treatment plants, water supply from groundwater systems that have fertilizers, pesticides, and industrial wastes. Also, the emission projected into the atmosphere through bakeries, factories and automobiles play a big role in contaminating the water all around.
One of the major causes of water pollution is the discharge of waste from industries. It is a common observation that industries find rivers and oceans a convenient place to dump their waste material into. The waste contains toxic substances and also includes elements like lead, mercury, nitrates and sulfates. They are quite harmful for humans as well as aquatic animals. A large amount of money is spent on treating the water bodies that get contaminated and making them suitable to use for drinking purposes again. Moreover, there are still risks of various diseases after consuming the water containing such toxic material. Often, hot or contaminated water is also released into the rivers from industries, which increases the overall temperature of the rivers, thus making them unfavorable for the aquatic flora and fauna to thrive.
This is another major cause that leads to the pollution of water bodies. Human settlements along the banks of rivers result in human and animal waste to be discharged into them. Sewage contains feces, urine and chemical wastes released by millions of people every day. The maltreated sewage is discharged in a wrong manner, besides there being leakages too. Sometimes, the sewage seeps through the ground and contaminates the groundwater. Instead of treating the sewage properly, most of the time, it is simply released directly into the sea or the rivers, thus polluting the marine life and habitat.
As the world continues developing, there has been a rise in the use of vehicles as well. There are millions of vehicles running on our roads and releasing toxic fumes of sulfates and nitrates every day. When released into the air, they come in contact with the water vapor present in the air, and become mild corrosive acids such as hydrochloric or sulfuric acid. They then return to the ground as acid rain. The acid percolates through the ground and mixes with the groundwater, which is then used by humans for consumption.
Burning of Coal
When coal is burned, it leads to the release of mercury into the atmosphere. This mercury reverts back to the Earth's surface and enters the rivers, lakes, and groundwater. As a result, all these water bodies get polluted, and are unsuitable for safe use. Consumption of water containing mercury is hazardous, more so for pregnant women and infants.
Slash and burn farming practices are a component in shifting cultivation agricultural systems. Fertilizers used for farming contain a large quantity of nitrogen and phosphorus. They enrich the soil near the lakes and rivers, and help algae grow at a considerable rate. The algae use all the oxygen and do not leave anything for the rest of the aquatic life around. Also, algae formation blocks the passage of light and air for the other aquatic animals. This has an adverse effect on the biological life of these aquatic animals, which is termed as Eutrophication.
Cattle and pig rearing results a significant amount of nutrient-filled waste. A lot of waste is discarded into the water bodies that are close by, and virulent pfiesteria toxin collects in these water masses. This makes it next to impossible for the aquatic animals there to survive.
Radioactive substances from nuclear power plants and industrial, medical and scientific use are also considered as contributors to the pollution of water. As the world is becoming more and more dependent on nuclear energy, there has been a tremendous increase in the amount of radioactive waste dumped into the aqueous regions. Uranium and thorium mining and refining are some of the examples. This kind of waste has a lot of side-effects on humans as well as aquatic life, and it is advisable to refrain from consuming water which has traces of radioactive substances. It has been proved that water containing radioactive substances causes genetic disorders.
In recent times, with the increase in traffic in all the oceans of the world, oil spills have become common, and are one of the major causes of water pollution. There have been numerous examples of large tanker ships spilling millions of gallons of oil into the seas. Sometimes, it is an accidental spill, but most of the time, waste, which is in form of oil is deliberately released into the seas and oceans. The spilled oil spreads to huge areas to form oil slicks, making it impossible for marine life and plants of the aqua to get proper sunlight and air. This causes the possibility of extinction of some of the already endangered species. If there are trials to sink the oil or chemically treat it, the marine and beach ecosystems also face further disruption.
A few other noteworthy sources of water pollution are:
- Atmospheric Deposition (Water body pollution caused by air pollution)
- Underground Storage (Pipelines and sewage systems below the surface, which leak, polluting the soil and nearby water bodies)
- Marine Dumping (All kinds of waste like paper, plastic, rubber, metal, etc., dumped into the oceans)
- Forest Fires (Uncontrolled fires in the wild pollute the water bodies nearby)
Water pollution has become a prime concern for most nations, and there is a shortage of quality drinking water all round the globe. It is high time that each one of us contributes towards making our environment clean and healthy. We can all provide a helping hand by minimizing the waste material in our own households, especially with the proper utilization of water. The governments of many countries have gone in for purification schemes of rivers and lakes. Only with a collective effort can this grave problem be tackled, before it is too late!