River Pollution across the World and it's Consequences

Increasing water pollution is a major problem around the globe. Not only oceans and seas face this pollution, but river and lakes are also part of this. Many fishes and other marine species are affected due to river pollution. Rivers are the major provider of freshwater, but when the level of pollution it's water becomes next to useless. Rivers played a major role in the urbanization of humanity. Many major rivers in the world, which once provided a large volume of fresh water and home for much beautiful flora and fauna, are now turning into sewages. River pollution has caused a major shift in the global ecosystem.

Increasing river pollution not only affects the fishes and animals in it but its direct effect is also shown in agriculture, groundwater, drinking water and many water-based industries. W.H. Auden once said, "Thousands have lived without love, not one without water". Yet humans have used every way to pollute the water. According to a study, about 80% world's untreated wastewater is dumped directly into water sources including rivers, lakes, seas and oceans.

Almost every country in the world is now fighting water pollution. Whether developed nation or developing nation, people are now facing challenges to even get pure drinking water. Here are some of the major factors that create water pollution.

(1) Industrial disposal:

Direct disposal of industrial waste into the river pollutes the water. Industries around the globe are dumping their toxic wastes into rivers legally or even illegally. Many governments are ignoring this industrial disposal and some have banned this. But still, none can stop water pollution. Industrial waste adds unwanted and harmful chemicals to the water. These chemicals not only kill fishes inside the river but also makes the water undrinkable and useless for agriculture. Such water creates many harmful health issues in humans. Severe damage to the stomach, kidneys and intestine may occur if such toxic water is consumed. Only in the US, around 370,000 industries directly dump their waste into rivers and other sources. 

Contaminated water has created diseases like diarrhoea, cholera, typhoid in many developing and poor countries. According to WHO, more than 800,000 around the globe die each year due to the consumption of contaminated water. Industries without any hesitation dump their waste into the rivers but on the other hand, the governments cannot treat the contaminated water or stop the pollution.

(2) Agriculture:

The agriculture sector is the biggest consumer of freshwater sources and is also the top contributor to river pollution. This sector uses almost 65-70% of the surface and underground freshwater. The unwanted use of pesticides and fertilizers eventually wash into the waterways and contaminate them. This adds unwanted nutrients to the canal or river water. Nutrition pollution is also the major reason which contaminates the river water. Nutrition pollution is nothing but the addition of elements like nitrogen, phosphorus, potassium into the water. All these elements are major constituents of fertilizers and pesticides. Apart from decreasing the quality, these nutrients increase the growth of unwanted algae and other microbes in the water. The algae blooms have many harmful effects on animals and humans. These algae blooms make river and lakes unsuitable for fishing and drinking. The growth of these algae is also very hard to stop. 

(3) Inorganic Pollution:

When we talk about inorganic pollution, the addition of heavy meats into the water tops. Heavy metal ions are released into the water by industries and agricultural activities. The human body requires a minute quantity of heavy metals for metabolism. However larger exposure of these metals to humans and animals causes many serious problems. The heavy metal ions include iron, zinc, lead, copper. manganese, vanadium etc.  In plants, excess of these metals may damage the cell membrane, decrease the seed growth, affects the photosynthesis activity and decrease the reproduction rate. In humans, excess of these metals creates eyes and skin irritation, severe headache, diarrhoea. Some long term effects like organ failure, low blood pressure, kidney stones, bone fragility may also occur. Water polluted with arsenic can create lung and bladder cancer. Lead when exposed to children may cause long term memory loss, lack of concentration and makes them more aggressive. The best example of heavy metal pollution is the Flint Water Crisis in Michigan state of the USA.  

(4) Local body disposal:

Local residents also play a major role in polluting the rivers in many areas. The daily kitchen and other organic waste flows directly in sewage and eventually merges into the rivers. Many countries have taken required steps to stop the flow of household organic and inorganic waste into the rivers. Water treatment plants have been constructed to treat the polluted water. But in many underdeveloped areas, the same polluted, untreated water reaches back to the houses. Wastes like plastic, papers, metals are also dumped into the rivers. All these factors have damaged a lot of marine ecosystem and humans too. This polluted water also reaches underground and pollutes the underground water sources. 

Here is the list of some of the most polluted rivers in the world.

1. The Ganga (India): The Ganges is the third largest river in the world and it is the source of water for more than 2 billion people. Such a high number of people using the Ganga water polluted the river for many decades. Religious baths and rituals have polluted the river to the next level. The holiest river in the world is now filled with plastics and toxins. 

2. Sarno River (Italy): The Sarno is the most polluted river in Europe. Excess agricultural waste and wastewater from nearby industries are the main factors polluting this river. More than 500 industries are dumping their toxic water directly into the river. The polluted water has caused liver cancer to many in nearby areas. 

3. Mississippi River (USA): Mississippi is the longest and most polluted river in the USA. The excess agricultural wastes polluted the river and eventually lead to eutrophication. Eutrophication is the process in which water gets excessively enriched with nutrients and minerals. This has lead to algae bloom in the river, which eventually killed the underwater plants and many fishes by blocking the sunlight.

4. Yangtze River (China): The Yangtze is the most polluted river in China. In 2016, 35.30 billion tonnes of waste and toxic water flowed into the river. Agricultural fertilizers and wastes from the ships played a major role in polluting the river. The river is surrounded by many densely populated areas, which creates even more pollution. Hence today it has become very difficult to prevent or stop pollution.

5. Citarum River (Indonesia): The Citerum is also one of the most polluted rivers in the world. More than 2000 industries has highly polluted the river with lead, arsenic and mercury. Apart from chemicals, there are more than 20,000 tonnes of other waste floating on the surface. This makes Citarum the world's dirtiest river. The water of Citerum is used by more than 25 million people for different purposes.