About 70 per cent of the earth's surface is under water. Twenty per cent of the land mass is also covered by ice and snow, the solidified forms of water. Ninety-seven per cent of all water is found in oceans; two per cent is ice, and only a meagre one per cent is for direct human use. However, 70 per cent of the drinking water is polluted and 80 per cent of the diseases are water-borne.
These facts and figures reveal the extent to which water regulates life on the earth. Despite it being an omnipresent substance and the fluid of all known living organisms, water is now increasingly becoming unfit to support healthy life. This has been encapsulated in the oft-repeated line from English poet Samuel Taylor Coleridge's poem, "The Rime of the Ancient Mariner": "Water, water everywhere and not a drop to drink!"
Meaning of Water Pollution
Stated in the simplest of terms, the contamination of water bodies is called water pollution. It is the abuse of ponds, lakes, reservoirs, rivers, and oceans through discharge of substances which adversely modify the quality of water. As all waste products are easily soluble in water, water pollution is a phenomenon that is easily caused.
According to the World Health Organisation, water gets polluted when its composition is altered to such an extent that it is rendered completely toxic and useless. Polluted water can be neither drunk nor used for agricultural purposes. On the other hand, it causes multiple health issues and diseases like diarrhoea, cholera, dysentery and typhoid, which kill half a million people every year. All aquatic life, including organisms and vegetation, is also immediately affected by water pollution.
Causes of Water Pollution
How are the water bodies turning into veritable pools of poison? Various forms of man-made waste – ranging from plastic bags to chemical discharge – are to blame for water pollution. Natural occurrences like volcanic eruptions and tsunamis also contaminate water and affect the underwater ecosystems.
Bacteria, viruses, parasites, fertilizers, pesticides, pharmaceutical products, nitrates, phosphates, plastics, faecal waste, industrial sewage and radioactive substances are counted among the water pollutants. The major human-induced causes of water pollution are global warming, deforestation, industrial and agricultural activities, livestock farming, disposal of garbage and faeces, maritime traffic, and fuel spillages. Some of the effects caused by each of these factors are mentioned below:
Rising mercury levels due to carbon dioxide emissions make water hot, thereby reducing its oxygen content. Felling of trees can empty water resources and generate residue which may breed harmful bacteria. Chemical dumping from industrial, agricultural and livestock farming units leads to a condition called eutrophication of water in which there is a proliferation of harmful algal growths, leading to ecological degradation in water bodies. According to the United Nations, more than 80 per cent of the sewage generated across the world, flows into the rivers and seas without any treatment. Plastic pollution in rivers and oceans is caused by the operation of fishing boats, tankers and cargo ships. Lastly, leakage from transportation and storage of oil and its derivative products also pollute the water resources.
Effects of Water Pollution
Water pollution takes a heavy toll on the environment, human and animal health, and global economy. It leads to depletion of the aquatic ecosystems and contamination of the food chain. The latter is caused by fishing in polluted waters and using waste water for agriculture and animal husbandry, activities which may inject toxins into the foods that we consume.
Pollution also causes shortage of potable water, which deprives millions of people around the world of access to clean, drinking water or sanitation, especially in the rural areas. Poor and underprivileged people fall sick and contract diseases like cholera, hepatitis A and dysentery due to consumption of contaminated water. According to the United Nations, diarrhoeal diseases cause the death of about 1,000 children per day in the world.
Contamination of groundwater through leaching from landfills and septic systems renders aquifers unsafe for use for an extended period of time.
Water Pollution in India
The issue of water pollution is acute in India with some of its rivers considered as the most contaminated in the world. The River Ganga, which flows spanking and clean from the Himalayas, gets all dirty along the way with faecal bacteria levels up to 31 million per 100 millilitres. A Sri Lanka-based agency has also termed a water stress zone, where one-third of its rivers are moderately or severely polluted. It is estimated that 80 per cent of India's water is severely polluted due to dumping of raw sewage, silt and garbage into the rivers and lakes. Experts predict that 40 per cent of Indians may not have access to a clean water source by 2030. Polluted water is cited as the major factor behind the poor health levels in India, especially in the rural areas.
Remedies for Water Pollution
It is a scary prospect that half of the human beings are likely to live in water-scarce areas by 2025. So it needs no emphasis to drive home the point that water is precious, and we that should all conserve and keep every drop pure. This is a gigantic task, but the global leaders must get their act right before it is too late. Carbon dioxide emissions must be reduced to prevent global warming and ocean acidification. Farmers also need to minimise the use of pesticides and nutrients on crops. Generation of waste water can be reduced, and the waste water generated can be treated for reuse in agricultural and energy production. Most importantly, single-use plastics that pollute the waters of rivers, lakes and oceans, should be discarded.
A lot needs to be done at the industrial and household levels to reduce the severity of water pollution. At the individual level, we can always strive for proper disposal of toxic chemicals. It is not a good idea to pour grease, fat, used cooking oil and medicines into the sink or drain. As companies are today selling non-toxic and biodegradable cleaners and organic pesticides, we must buy them. These steps must be adopted on a sustained basis to reduce the negative impact of water pollutants. Every action taken, both individually and on a larger scale, can make a huge difference to the cause of conserving our water resources for posterity.
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