The quality of water utilized and consumed is an important factor that determines the welfare of the living things in the world. The contaminated water is the cause for many waterborne diseases, which affects people and consumes their lives. These polluted water bodies not only wipe out the population, but also leave behind awful health problems that cannot be treated. So, it is important to know the importance of clean water and also the bad effects of contaminated water.
Water - A Precious Resource
Water occupies one-third of the earth's surface. They exist in the form of seas and oceans, icecaps, snow, water vapor, etc. Underground water, pond water and lake water are potable. But why is water so necessary? Imagine for some reason, your family gets only one bucket of water everyday for a week. Would you be able to manage with the limited amount of water? Do all organisms require water? The following paragraph will just tell you how valuable is water for survival of all living things on earth.
All the cellular processes take place using water medium. All reactions within our cells occur between the substances that are dissolved in water. Also, the movement of substances in our body is in dissolved form. So how important is water for us to live? Bodies of terrestrial living forms cannot tolerate or get rid of saline water from their body and so they require freshwater. Thus for humans, animals and plants to survive on land, water should be easily accessible. The availability of water not only decides the number of individuals of each species that can survive in a particular area, but also the diversity of life there. Of course, other factors like temperature, nature of soil, etc., also determine the survival of the species. It is an undeniable fact that water is an important resource that determines life on earth.
Effects of Water Pollution
Fertilizers and pesticides that we use in our farms are dissolved in water, and some amount of these dissolved substances are washed into water bodies and pollute them. Sewage and waste from towns, cities, factories, etc., are also dumped into rivers and lakes. Some industries use water for cooling in industrial operations and later drain the hot water into water bodies. This causes change in the temperature of the water and it harms the life forms and affects the balance between various organisms in the water bodies. Acid mine drainage also contaminates water.
- Addition of undesirable substances like detergents, polychlorinated biphenyls, mercury salts, etc., cause harmful effects on water bodies.
- Any changes that reduce the amount of dissolved oxygen would badly affect the aquatic organisms.
- The eggs and larvae of aquatic creatures get destroyed by changes in the temperature of water bodies as they are very susceptible to such changes.
Water Pollutants and their Long Term Effects
2,4,5-T (trichlorophenoxy acetic acid, which contains the impurity dioxin), 2,4-D (dichlorophenoxyaceticacid) are the two common pesticide components that cause water pollution. The effects of pesticides on living things are mostly chronic. It reduces the competence of our immune system, because of which, we are easily prone to various diseases. The fish in the water are susceptible to cancer and tumors due to the presence of harmful pesticides.
The most harmful and toxic elements that affect the water bodies are heavy metals such as cadmium, lead, iron and mercury and they also hinder the transportation of fluids through the cell wall. They also immobilize enzymes as they have strong affinity for sulfur bonds present in enzymes. These substances can produce physiological poisoning by getting accumulated over the tissues of water creatures. The toxic effects of mercury are neurological damage, birth defects, and chromosome breakage. Arsenic is one of the most important water polluting agents as it is a carcinogen (cancer causing agent). Apart from cancer, it also leads to circulatory problems and respiratory problems.
The inorganic pollutants that cause adverse effects on water bodies are as follows:
- Cyanide exists in water as hydrogen cyanide, and can cause nerve damage and thyroid problems.
- Ammonia is formed during microbial degradation of biomass and organic matters. The caustic nature of ammonia, damages gills of fish.
- Hydrogen sulfide which evolves from geothermal waters, and wastes from paper and textile mills, causes nervous system poisoning.
Eutrophication and Algal Decomposition
Excess of nutrients get into the lake and other water bodies usually caused by run-off fertilizers, animal waste and sewage. This excessive growth of nutrients causes algal deposits on the rivers. After some days, the algae decomposes producing foul smell and blocks the penetration of sunlight. The oxygen content in the water reduces due to scarcity of light and causes anaerobic conditions, which is not good for the plant and animal life in the water body.
Radioactive elements such as radon, radium-226, etc., can be fatal if found in water and consumed. Radon is the most significant element that can cause lung cancer when consumed in a dissolved state or inhaled in its gaseous form. Strontium-90 and tritium are radioactive elements that get dumped into water during nuclear testing. They cause genetic mutations and pose destructive effects on our genes that can pass on to future generations also.
Most of the diseases that strike human beings are water-borne. They are typhoid, cholera, paratyphoid fever, bacillary dysentery, infectious hepatitis, poliomyelitis, etc. So, in order to avoid these harmful effects, follow the ways to prevent water pollution and more importantly, drink clean and purified water and never compromise on health.