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Summary
Chapter 12 discusses noise and radiation pollution, two significant environmental concerns. Noise pollution is defined as unwanted sound that negatively affects human health and the environment. It is particularly problematic in urban areas, such as Dimapur and Kohima in Nagaland, where it comes from traffic, industrial activities, festivals, and household gadgets. The chapter outlines the sources of noise pollution, including machines, vehicles, and loudspeakers. Noise pollution can lead to various health issues, such as hearing loss, high blood pressure, and mental stress. The chapter also describes the measurement of noise using decibels and provides examples of noise levels in different Indian cities.
Radiation pollution is another concern covered in this chapter. Radiation occurs when unstable atoms release energy in an effort to become stable, a process known as radioactivity. Radiation can come from natural sources, like cosmic rays, or from man-made sources, such as nuclear power plants and medical equipment. The chapter explains that while some radiation exposure is normal and usually harmless, excessive exposure can lead to severe health problems, including cancer and genetic mutations. The text also mentions the catastrophic effects of nuclear accidents, such as those in Chernobyl and Fukushima, which caused widespread radiation pollution.
The chapter concludes by highlighting the harmful effects of both noise and radiation pollution on human health, such as deafness and cancer, respectively. It suggests measures to reduce these types of pollution, including better safety practices in industries and nuclear facilities, as well as minimizing noise in residential areas.
Textbook solutions
Multiple-Choice Questions
1. Most serious and pathological effect of noise pollution is
A. Mental retardation
B. Nausea
C. Sweating
D. Deafness
Answer: D. Deafness
2. Which of the following sound sources can cause eardrum rupture on prolonged exposure?
A. Rustling leaf
B. Busy city street
C. Jet plane at takeoff
D. An average factory
Answer: C. Jet plane at takeoff
3. Which of the following is an immediate defect due to radiation exposure?
A. Leukaemia
B. Carcinogenesis
C. Radiation sickness
D. Shortening of life
Answer: C. Radiation sickness
4. A unit used to measure the intensity of sound is
A. Decibel
B. Metre
C. Joule
D. Noise
Answer: A. Decibel
5. Radiation effects that damage the genes and chromosomes affecting future generations are called
A. Physiological changes
B. Psychological changes
C. Somatic effects
D. Genetic effects
Answer: D. Genetic effects
Short Answer Questions
1. Define radiation.
Answer: Radiation is a phenomenon which involves the movement of energy through space.
2. What is half-life of an isotope?
Answer: Time taken by the radioactive element to decay exactly half the number of atoms, which were present in the beginning.
3. What are the sources of noise pollution?
Answer:
- Traffic noise
- Industrial noise
- Festival or cultural noise
- Noise generated from construction activities, DG sets, etc.
4. What are radioactive isotopes?
Answer: Radioactive isotopes are atoms that have unstable nuclei and emit radiation as they decay to stable forms.
5. Why are Dimapur and Kohima cities of Nagaland the most noise polluted?
Answer: Excessive noise is an effective polluter of the environment in the urban areas, particularly Dimapur and Kohima cities in the Nagaland state. Traffic noise, industrial noise, festival or cultural noise, along with noise generated from construction activities, DG sets, etc., are the most effective sources of noise pollution.
6. Which level of sound create discomfort to the people?
Answer: Some people feel discomfort with a sound of 85 dB whereas most do not feel discomfort with a sound of 115 dB.
7. What are the different effects of ionising radiation?
Answer:
- Somatic effects: Cell damages that pass on to succeeding cell generations.
- Genetic effects: Damages to genes and chromosomes that affect future generations.
Long Answer Questions
1. Give some examples of industrial activities producing noise.
Answer: Examples of industrial activities producing noise are:
- The noise produced by machines in the factory is a major occupational health hazard.
- Traffic noise, industrial noise, festival or cultural noise, along with noise generated from construction activities, DG sets, etc., are the most effective sources of noise pollution.
2. What are the effects of high noise on human body? Describe with examples.
Answer: The effects of high noise on the human body are:
Consequences of noise pollution
(i) Deafness
(ii) Increased blood pressure
(iii) Increased sweating
(iv) Mental retardation
(v) Nausea
(vi) Fatigue
(vii) Giddiness
(viii) Visual impairment
Noise pollution causes discomfort and may lead to temporary or permanent impairment of hearing. It has certain definitive ecological and pathological effects on biota and human beings. For instance, supersonic jets produce noise of a very different and high order, in the form of sudden but repeated shock waves, which are suspected to cause disturbance to wild birds and animals as well as buildings.
3. How does radiation pollution cause genetic defect?
Answer: Radiation is known to cause genetic disorders in living organisms through various mutations affecting adversely the living organisms. Radiation may also cause galls, cataracts, tumours, and degenerative changes and other malfunctions in the tissues of the body of the organisms. Transmutation of the radioactive isotopes incorporated in the structural component of the body of the organisms causes complete chaos in the system as the very basis of internal structure may crumble down. Moreover, such an individual who is loaded with radioactive substances is a moving source of radioactivity and health hazard for others who come in contact with him. In addition to these, our immunity system will be adversely affected, leading to a reduction in our defences against a variety of infections. The biological effects of ionising radiation may be divided into two main groups: somatic and genetic effects.
4. How is human body affected by radiation exposure?
Answer: Radiation is known to cause cancer and other pathological disorders. It is also known to cause genetic disorders in living organisms through various mutations, affecting adversely the living organisms. Radiation may also cause galls, cataracts, tumors, and degenerative changes and other malfunctions in the tissues of the body of the organisms. Transmutation of the radioactive isotopes incorporated in the structural component of the body of the organisms causes complete chaos in the system as the very basis of internal structure may crumble down. Moreover, such an individual who is loaded with radioactive substances is a moving source of radioactivity and health hazard for others who come in contact with him. In addition to these, our immunity system will be adversely affected, leading to reduction in our defenses against a variety of infections. The biological effects of ionizing radiation may be divided into two main groups: somatic and genetic effects.
5. Explain the mobile tower radiation and the provisions made under Environment (Protection) Act for it.
Answer: India being one of the fastest growing telecom markets in the world, it has witnessed unprecedented increase in tele-density on a large scale increase in the number of telecom towers in the country. There are more than 6,50,000 telecom towers in the country, out of which 3,00,000 telecom towers have gensets also as a backup power supply source. In this regard, the Central Pollution Control Board has been receiving numerous public complaints including noise and emission from DG sets, health hazards due to mobile tower radiation, etc. The board has informed mobile tower service provider to ensure compliance of noise and emission norms of DG sets attached to the mobile towers. The compliance of the noise and emission standards as per the provisions made under the Environment (Protection) Act, 1986 is to be ensured by the service providers through regular inspection of the facilities. In case of violation of the said norms, action as deemed fit shall be taken and further informed service providers to contact the office.
6. Differentiate between Natural and Man-made sources of radiation by giving examples?
Answer: Important sources of radiation can be grouped into: (i) natural sources of radiation, and (ii) man-made sources of radiation.
(i) Natural sources: Earth’s continuing natural processes are an important source of radiation for the biosphere. In addition, Earth’s surface is regularly irradiated by X-rays, cosmic and ultraviolet rays from outer space, which are another source of natural radiation.
(ii) Man-made sources: Man-made sources of radioactivity include nuclear reactors, diagnostic and therapeutic application of radioactivity, atomic tests and weapons, and miscellaneous uses of radioactive material. The main sources of radiation are the nuclear wastes from the nuclear power plants and other installations related to them. Radiation is also released by those units which are involved in processing raw materials for installations. The other major source could be the fallout of a nuclear bomb explosion. Fallout of nuclear tests could contaminate every part of the Earth’s surface and all its inhabitants.
Think and Answer
1. You often listen to loud music playing in your neighbourhood during a marriage or any other occasion which creates noise pollution. What is your opinion regarding its effect?
Answer: Loud music during events like marriages in the neighborhood can be very disturbing. It makes it hard to focus on studies and can be really stressful, especially during exams. The constant noise can cause headaches and make it difficult to sleep at night. This kind of noise pollution is not just annoying but can also affect our health if it happens too often. It’s important for everyone to understand how harmful this can be and try to keep the volume down during such occasions.
2. You must have observed the effects of noise on the people inside your house. What are these effects and what can be done to solve this problem?
Answer: The noise from outside, like loud music or traffic, affects everyone in my house. It becomes hard for my parents to concentrate on their work and for me to study. Sometimes, it even wakes up my younger siblings at night, making them cranky the next day. To solve this problem, we try to close all the windows and use thick curtains to block out the noise. We also avoid making too much noise inside the house to keep it peaceful. Talking to our neighbors about keeping the noise levels down during late hours could also help.
Extras MCQs
1. What is the noise level that can cause hearing damage if prolonged?
A. 60 dB
B. 80 dB
C. 90 dB
D. 120 dB
Answer: C. 90 dB
24. What is a consequence of exposure to high levels of radiation on the human immune system?
A. Increased resistance to disease
B. Improved overall health
C. Reduced defenses against infections
D. Enhanced immune response
Answer: C. Reduced defenses against infections
Extra Questions and Answers
1. What is noise pollution? Where is it commonly found?
Answer: Noise pollution may be defined as unwanted sound released into the atmosphere without concern for its adverse effects. It is a common feature of cities.
22. What are the biological effects of ionising radiation?
Answer: The biological effects of ionising radiation are divided into two main groups: somatic and genetic effects. Somatic effects include immediate effects such as radiation sickness and acute radiation syndrome, as well as delayed effects like leukaemia, carcinogenesis, foetal development abnormalities, and shortening of life. Genetic effects include chromosome mutations and point mutations. Radiation pollution causes various health issues, including cancer and other pathological disorders. It can also lead to genetic disorders through mutations, affecting living organisms adversely. The text mentions that radiation may cause galls, cataracts, tumors, degenerative changes, and other malfunctions in tissues. These effects can be particularly devastating, leading to the collapse of the body’s internal structure and making individuals loaded with radioactive substances a moving source of radioactivity, posing a health hazard to others.
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