ICSE Geography: EFFECTS OF POLLUTION Class 9

EFFECTS OF POLLUTION

 

Q1. How does noise pollution affect animals?

Noise from industries, railways, crackers, explosions, and commotion in the cities and aircraft, affect animals, birds, mice, fishes and domestic animals in the following ways.

(i) Birds avoid migrating to places where noise level is above 100 dB.

(ii) The noise emissions caused by supersonic aircraft and railways may cause miscarriage in mammals and fishes as well.

(iii) Some birds have been found to have stopped laying eggs due to noise pollution.

 

Q2. What major harm is done to human beings by air pollution?

Major harm done to human beings by air pollution are-

(a) The short-term effects are- Irritation in the eyes, nose and throat respiratory infections like bronchitis, pneumonia, headaches, nausea, vomiting, dizziness, convulsions and allergic reactions

(b) The long-term effects are- Chronic respiratory diseases, Lung cancer and cardiovascular diseases and coma, Damage to the nerves, brain, liver, kidney etc.

 

Q3.What is the effect of oil spills on marine life?

Sea water polluted with crude oil leakage causes oil spills which contaminate sea water and lead to the death of marine organisms.

Oil spills kill marine mammals such as whales, dolphins, seals, and sea otters. Oil can clog blow holes of whales and dolphins, making it impossible for them to breathe properly and disrupting their ability to communicate.

Oil coats the fur of otters and seals, leaving them vulnerable to hypothermia.

Q4. What causes waterborne diseases? Name two waterborne diseases.

Most of the waste waters especially sewage contain pathogens like bacteria, viruses, and protozoa. These pathogens enter the human body from contaminated drinking water and are responsible for several waterborne diseases like cholera, typhoid etc.

 

Q5. In what way does soil pollution affect human beings?

Soil pollution affects human beings in the following ways-

     (i) Soil contains many pathogenic bacteria, viruses and intestinal worms which are transmitted to man by the consumption of fruits and vegetables. These pathogens cause various types of diseases.

    (ii) Radioactive fallout on vegetation is the source of radioisotopes which enter the food chain through the grazing animals. Some of these radioisotopes cause abnormalities.

     (iii) Use of animals and human excreta as manure pollutes the soil. Excreta contains pathogens that contaminate the soil and vegetable crops and affect the health of human beings.

 

Q6. Give the impact of radiations on human body.

Radiations affect living organisms. They cause harmful changes in the body cells and at genetic level. Some impacts of radiations on human body are-

Genetic variations — The damage caused by radiations is often seen in the offsprings and may be transmitted to many generations.

Somatic variations — Short term exposures to radiation can cause damage to organs of the body. The harm done by them includes breast cancer, thyroid cancer, lung cancer and brain cancer, sterility and defective eyesight.

 

Q7. State with examples the effects of radiations on the human beings and environment.

Example of radioactive accident: There was a radioactive accident in 1986 in Chernobyl in the Ukraine. On 26th April, 1986, a reactor at the nuclear power complex at Chernobyl exploded.

There was a massive steam explosion. The core of the reactor combined with water to produce hydrogen which exploded blowing toxic radioactive gases into the air. There were numerous fires. The Chernobyl accident is considered as the most disastrous nuclear power plant accident, both in terms of cost and casualties.

Due to the accident, 237 people suffered from acute radiation sickness, of whom 31 died within the first three months. After the disaster, four Sq.kms of pine forest near the reactor turned reddish brown and died, earning the name of the 'Red Forest'. Some animals in the worst hit areas died or stopped reproducing.

(i) Effects of radiations on human health: Check Answer Q20

Effects of radiations on the environment: Radiations emitting from radioactive materials and the disposal of radioactive wastes cause pollution and damage the environment. The high-level products of nuclear wastes remain in the environment for several hundred years. Other radioactive threats to the environment are the accidents connected with the activities of nuclear reactors, nuclear-powered vessels and satellites etc.

 

Q8. State briefly how is noise pollution detrimental to human health.

Noise pollution is detrimental to human health because of the following effects-

Effect on hearing or deafness — Continuous exposure to noise levels above 100 dB has an adverse effect on hearing ability within a fairly short time.

Effect on Communication — External sounds can interfere with communication at important places like schools and offices. It also effects the use of radio and television.

Interference with sleep — Noisy conditions near residential areas at night cause difficulties in sleeping.

Mental or Physiological effects — Even short exposure to noise in excess of about 100 dB can lead to mental illness, cardiovascular diseases, stomach ulcers, respiratory disorders, headache and dizziness. It effects the foetus as well.

Effects on physical health and psychological problems — Exposure to noise of about 190 dB can cause permanent damage to hearing. It also leads to problems like speech interference, annoyance, fatigue, sleep interference and emotional distress.

 

Q9. What is Biomagnification, Bioaccumulation and Eutrophication?

Biomagnification means increasing the concentration of various toxic substances along the food chain. Toxic substances at the level of primary producers get concentrated at each trophic level as they move up the food chain.

“The phenomenon of concentrated toxic deposition at the higher trophic level is known as bioaccumulation.”

For example, if there are traces of toxic chemicals in water, then their concentration in algae will be much higher. When fish eat the algae, the concentration of toxins will increase further. Therefore, accumulation of a small amount of toxic chemicals in water can have a serious impact on the fish that live in it.

Eutrophication is the process in which excessive growth of ALGAE occurs in a water body due to excessive minerals and nutrients. This process may result in oxygen depletion of the water body after the bacterial degradation of the algae. One example is an “algal bloom”. Eutrophication is usually induced by the discharge of nitrate or phosphate-containing detergents, fertilizers, or sewage into an aquatic system.

 

Q10. Name three common air pollutants and their effects on human health.

Air Pollutants	Their effects on human health
Carbon monoxide	It damages lungs, weakens bones, reduces the oxygen carrying capacity of blood and damages the heart.
Sulphur dioxide	It obstructs breathing, causes irritation of eyes and throat.
Suspended particulate matter	It causes asthma, irritation of eyes and cancer.