Water pollution (or oceanic contamination) is the defiling of water bodies, generally because of human exercise, in a way that adversely influences its natural quality. Water pollution decreases the capacity of the waterway to give environmental benefits. Water bodies incorporate lakes, waterways, seas, springs, repositories, and groundwater. Water pollution results when toxins are brought into these water bodies. Apart from harm to numerous species, water pollution can also prompt water-borne illnesses for individuals.

Sources of Water Pollution

Water pollution is generally credited to the following sources:

• Sewage
• Industry
• Farming
• Metropolitan spillover, including stormwater.
• Decaying animals and plants, domestic sewage, animal excreta and waste, discharge from food processing factories.
• Synthetic fertilisers
• Chemical factories 
• Erosion of soil by strip mining and agriculture 
• Substances used for destroying pests, and unwanted plants
• Mining of minerals that contain uranium.
• The water is utilised for cooling purposes in industries.

Causes of Water Pollution

• Urbanisation
• Industrial water waste
• Agricultural source
• Nuclear waste 
• Underground water pollution
• Marine pollution

Urbanisation

Urbanisation subsumes roads, houses, commercial spaces, and skyscrapers. Sometimes, to accommodate buildings, the channel of the streams is diverted, which disturbs the flow of water instead. Such areas are prone to water lags during the monsoon season.

Though urbanisation is considered advancement made towards the growth of the society, a rapid growth in population, and consequently urbanisation, raises the potentiality of groundwater pollution, which is caused due to dumping of waste material (inclusive of human excretes and chemicals.)

Industrial Waste

Pollution is also caused by industries that discharge several toxic chemicals affecting water sources, aquatic life forms, terrestrial animals and humans when such toxic water is consumed.

Agricultural Source

The chemicals used in agriculture, such as pesticides and insecticides, are rich in nitrogen, potassium, hydrocarbon, metallic salts, and phosphorus. When such fertilisers are used in excess, it reaches the groundwater through micro-organisms or roots of the crops or trees and mixes with the surface water such as lakes, rivers, or streams.  

Nuclear Waste

Nuclear power plants, hospitals, and large-scale science projects discharge massive radioactive waste daily. The nuclear waste consists of several reactive chemicals such as uranium, and it comes with no permanent disposal system. Such remains for decades without perishing. When this waste gets merged with the surface water, it gets highly reactive and loses its pH value for purity for consumption. This may lead to:

• Cancer (Carcinogenic)
• Damage in the chromosome (mutagenic)
• Congenital disabilities (Teratogenic)

Thermal Pollution

When heat is released in water, it decreases the capacity of water to hold dissolved oxygen in solution. With low levels of oxygen, aquatic species start to die.

Marine Pollution

The ocean acts as the ultimate sink of all-natural and artificial pollutants and has become an immediate remedy for dumping garbage. The ocean holds:

• Sewage and garbage of the coastal cities
• Toxins and impurities from rivers
• Navigational discharges
• Oil spills

Effects of Water Pollution

• Effects on aquatic ecosystem
• Effect on human health
• Effects on groundwater
• Effects on ecosystem

Effects on aquatic ecosystem

The ecosystem is prone to respond to small changes in the environment. Thus, the increase of the chemicals in the water body effectively grows algae upon such water bodies, which increases bacteria, decreasing the percentile value of the oxygen present in the water.

Effects on human health

• The contaminated water contains viruses, bacteria, and other chemicals which cause severe diseases such as cancer, jaundice, various other diseases, etc.
• Mercury mixed with water produces methyl mercury, and problems such as numbness in limbs, birth issues, blurring of vision (Ex. Minamata Disease).  
• Water mixed with cadmium causes diseases in bones and joints.
• Components of lead in the water shall result in anaemia, loss of muscle power, etc.

Effects on groundwater

Exposure to groundwater may lead to the leaching of arsenic from soil and rock sources thus contaminating it. Consumption of this water may cause black foot, cholera, skin cancer, etc.

Control Measures

The best way to avoid water pollution is to reduce harmful substances in such water bodies. There are several measures which we can take to protect the water resources. They are as follows :

• Conserving water
• Better treatment of sewage
• Eco-friendly products

Conserving Water

•  Wastage of water is a global issue. Thus, domestic conservation can make a huge difference.

• Better treatment of sewage – treating the toxic waste product before disposing it to the water body reduces water pollution to a greater extent, resulting in reutilization of such water.

• Eco-friendly products – having or utilising soluble products in the water shall reduce the danger of water pollution and diminish aquatic life.

Conclusion 

Since water is one of the significant sources of survival, it is essential to protect water bodies. When water is prone to exposure to hazardous gases, it becomes less suitable for consumption as water quality deteriorates. Water pollution can occur due to domestic sewage, farms, industries, etc. We humans cannot live with contaminated surface water or poisonous aquatic animals. Thus, it is necessary to keep the environment clean to remain healthy. It is important to follow the quality standard for public water set by WHO and EU.