Effects of water pollutants

Effects of water pollutants

Heavy metals from industrial processes can accumulate in nearby lakes and rivers. These are toxic to marine life and can affect the rest of the food chain.

Industrial waste contains toxic compounds that damage the health of aquatic animals and those who eat them. Toxins affect the reproductive success of marine life and disrupt the structure of an aquatic environment.

Microbial pollutants from sewage often result in infectious diseases that infect aquatic life and terrestrial life through drinking water. This causes diseases such as cholera and typhoid fever.

Organic matter and nutrients causes an increase in aerobic algae and deplete oxygen level. This is called eutrophication and causes the suffocation of fish and other aquatic organisms.

Sulphate particles from acid rain make the water acidic. This damages the health of marine life and often increases the number of mortalities within an environment.

Suspended particles can reduce the amount of sunlight penetrating the water, disrupting the growth of photosynthetic plants and micro-organisms. When present in fresh water, they reduce the quality of drinking water for humans.

Diseases caused by water pollutants

Cholera – a bacterial disease which infects the small intestine

Typhoid  Fever- a bacterial disease

Hepatitis– caused by viruses or toxins like alcohol, leading to inflammation of the liver

E-Coli Infections- a bacterial disease which causes food poisoning

Malaria- caused by protist, leading to fever and headaches

Dengue-  viral disease, leading to fever, headache, muscle and joint pains, and skin rash  

Causes of water pollution

Sewage

(Wastewater)

Marine Dumping

Underground storage leakages and oil

pollution

Atmospheric

deposition and Global warming

Eutrophication

Industrial waste

Sewage…• When untreated water is drained off in

large quantities into rivers, it stagnates the river.

• Effluents contained in sewage water contain innumerable pathogens and harmful chemicals that spread various diseases.

• Other problems include eutrophication, poisoning and killing aquatic organisms, etc . 

Marine Dumping

• Waste materials are often deposited by people, factories and industries, tankers and ships, etc into water bodies. This leads to marine pollution.

• The adverse effects of marine pollution are two- fold:

a) The wastes that are dumped into the oceans tend to have toxic substances which soak in all the oceanic oxygen leading to a marked depletion of oxygen available to mammals and other fishes causing them to die in their natural habitat.

b) The toxic substances consumed by the fishes lead to complications in the humans consuming these affected fishes.

Industrial waste…• Many industries use freshwater as a source to

carry away harmful chemicals and waste away from the plant and dump them into rivers, lakes and oceans.

• This waste includes some harmful pollutants such as asbestos, lead, mercury, nitrates, phosphates, oils, sulphur, petrochemicals and dangerous salts. These pollutants may cause a great threat to living beings.

Underground storage leakages and oil

pollution… • Underground storage tanks often store substances like petroleum. If UST’s made from steel pipes are directly exposed to the environment, the steel can corrode and cause leakages, affecting surrounding soil and groundwater.

• Besides, oceans are polluted by oil on a daily basis from oil spills, run-offs, etc. An oil spill from a tanker is a severe problem because there is such a huge quantity of oil being spilt into one place. Oil cannot dissolve in water and forms a thick sludge which suffocates fish, gets caught in the feathers of marine birds stopping them from flying and, blocks light from photosynthetic aquatic plants.

Eutrophication…

• Sometimes, fertilizers used in farming run-off into nearby water, causing an increase in nutrient levels. This causes phytoplankton to grow and reproduce more rapidly, resulting in algal blooms.

• This bloom of algae disrupts normal ecosystem:

a) The algae may use up all the oxygen in the water, leaving none for other marine life.

b) The bloom of algae may also block sunlight from photosynthetic marine plants under the water surface.

c) Some algae even produce toxins that are harmful to higher forms of life. This can cause problems along the food chain and affect any animal that feeds on them.

Atmospheric deposition and Global

warming…• Atmospheric deposition is the pollution of water caused by air pollution. A common example is that of acid rains- when acid rains are deposited In water bodies, aquatic life is harmed.

• Besides, an increase in the surrounding temperature in turn leads to an increase in the temperature of the water which can result in the death of many aquatic organisms and disrupt marine habitats.

Case study 1

• One of the most terrifying effects of water pollution came to light when pesticide residues were found in bottled water.

• Between July and December 2002, the Pollution Monitoring Laboratory of the New Delhi-based Center for Science and Environment (CSE) analyzed 17 brands of bottled water commonly sold in areas that fall within the national capital region of Delhi.

• The manufacturing plants of most brands are situated in the dirtiest industrial estates or in the midst of agricultural fields.

•Most companies use bore-wells to pump out water from the ground from depths varying from 24-152 m below the ground.

•The raw water samples collected from the plants also revealed the presence of pesticide residues.

• Water is filtered using membranes with ultra-small pores to remove fine suspended solids and all bacteria and protozoa and even viruses.

• Manufacturers claim to use processes like filtraton, activated charcoal adsorption process, reverse osmosis and granular activated charcoal methods.

• But the presence of pesticide residues points to the fact that either the manufacturers do not use the treatment process effectively or only treat a part of the raw water.

• The low concentrations of pesticide residues in bottled water do not cause acute or immediate effects.

• However, repeated exposure even to extremely minute amounts can result in chronic effects like cancer, liver and kidney damage, disorders of the nervous system, damage to the immune system and birth defects.

• After six months, it was reported that these pesticides were found in popular cold drink brands sold across the country. This is because the main ingredient in a cold drink is water.

• There were no standards for bottled water in India till September 29, 2000, when the Union Ministry of Health and Family Welfare issued a notification amending the Prevention of Food Adulteration.

•The BIS (Bureau of Indian Standards) certification mark became mandatory for bottled water from March 29, 2001.

Case study 2

• Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Gulf of Mexico, the Galapagos Islands, France and many other places. 

• The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons

• When an oil slick from a large oil spill reaches the beach, the oil coats and clings to every rock and grain of sand. If the oil washes into coastal marshes, mangrove forests or other wetlands, fibrous plants and grasses absorb the oil, which can damage the plants and make the whole area unsuitable as wildlife habitat.

• A 2007 study conducted by the National Oceanic and Atmospheric Administration (NOAA) found that 26, 000 gallons of oil from the Exxon Valdez oil spill was still trapped in the sand along the Alaska shoreline.

• Oil, a product that we often use to keep warm, can cause hypothermia in marine animals. As oil mixes with water, it forms a substance called “mousse”, which sticks to feathers and fur.

• A bird's feathers are filled with air spaces that act as insulation and keeps the bird warm. When a bird gets coated with oil, the feathers lose their insulating ability and the bird could die of hypothermia.

• There’s so much damage done . The oceans are still polluted with oil from various incidents. With oil spills happening regularly, more oil is being dumped into the ocean- more animals are dying .