Kids Learning Science V Term-III

5th Standard Science Term-III

AIR Continue...

  2. Effects of Air Pollution  

Air pollution affects all living organisms including man.  It causes serious health problems to human beings and affects both plants and animals.  It brings about a lot of changes in the climate and environment also.  In this section, let us learn about some of the effects of air pollution.

✧ Diseases

Air pollution causes several respiratory problems.  Many people have died due to air pollution.  Air pollutants cause pneumonia and asthma in children.

✧ Global Warming

Air pollution results in the accumulation of carbon dioxide in the atmosphere.  When gases like carbon dioxide are present in the atmosphere in large amount, they increase the atmospheric temperature.  With increased temperature, melting of ice and icebergs in polar regions and increase in sea levels are taking place.  It affects the organisms living there.

✧ Acid Rain

As we saw earlier, harmful gases like nitrogen oxides and sulphur oxides released into the atmosphere while burning fossil fuels.  When it rains, the water droplets combine with these gases nd fall on the ground in the form of acid rain.  Acid rain affects human, animals, and crops.

✧ Depletion of Ozone Layer

Ozone molecules are present in the Earth's stratosphere and they protect humans from harmful ultraviolet (UV) rays.  Chlorofluorocarbons, released into the atmosphere by human activities deplete the ozone layer.  As the ozone layer is depleted, UV rays reach the earth and they cause skin and eye related problems to us.

✧ Marine Life

Large amount of nitrogen present in some fertilizers in washed into the water bodies.  They cause the growth of green algae in the water bodies.  This is called Eutrophication.  This adversely affects fish, plants and animal species.

✧ Effect on Wildlife

Harmful substances present in the air affect wild animals.  Wild animals move to a new place when the air is polluted.  When their habitat is changed they face extinction.

  3. Prevention of Air Pollution  

If the air pollution increases at this rate, then there will be no life on the earth in the future.  Future generation will be affected very badly.  So, we need to take some measures to avoid air pollution.  Some of them are discussed below.

➜ Major pollutants which cause air pollution come from automobiles.  Using public modes of transport can reduce the rate of pollution.  We should encourage others to use public transport.

➜ By reducing the usage of fossil fuels we can save the environment.

➜ Using non-renewable energy resources like solar energy and wind energy instead of conventional energy can reduce air pollution.

➜ We need to reduce our usage of things.  We can reuse of recycle few items.

➜ Switch off fans and lights when you are not using them.

➜ CFL bulbs consume less electricity.  By using these bulbs we can save energy.

➜ Planting more trees can reduce the amount of carbon dioxide in the atmosphere.

  IV. Airborne Diseases  

Diseases which are caused by microorganisms and communicated through air are called airborne diseases.  When we breathe in air, there are chances for the microorganisms present in the air to get into our body.  Bacteria, virus and fungi are the microorganisms which cause airborne diseases.  These microorganisms are transmitted through droplets caused by coughing or sneezing, breathing and talking.  Let us study about some of the airborne diseases here.

  1. Diseases caused by Bacteria  

Diphtheria, Whooping Cough and Tuberculosis are some of the common airborne diseases caused by bacteria.

✧ Tuberculosis

Tuberculosis is caused by the bacteria, Mycobacterium tuberculosis.  When we breathe, the bacteria present in the air get into the lungs and affect it.  Infected person has to be treated with anti-tuberculosis drugs for a period of 6 months to 1 year.

✧ Whooping Cough

Whooping cough is caused by Bordetella pertussis.  It also affects the respiratory tract and causes mild fever severe cough ending in whoop.

✧ Diphtheria

It is caused by the bacteria, Corynebacterium diphtheriae.  It generally affects the upper respiratory tract (nose and throat) and causes fever, sore throat and chocking of air passage.

Disease	Causative Organism	Mode of Transmission	Tissue/Organ affected	Symptoms
Tuberculosis	Mycobacterium tuberculosis	Droplet infection from sputum of infected persons	Lungs	Persistent cough, Chest pain, Loss of appetite, Loss of weight
Whooping Cough	Bordetella pertussis	Droplet infection from sputum of infected persons, Direct contact.	Respiratory tract	Mild fever, Severe cough ending in whoop
Diphtheria	Corynebacterium diphtheriae	Droplet infection from sputum of infected persons	Upper Respiratory tract	Fever, Sore throat, Choking of air passage

 

  2. Diseases caused by Virus  

Some diseases are caused by the virus present in the air.  Common cold, influenza, measles, mumps and chicken pox are some of the diseases caused by virus.

✧ Common cold

Common cold is an infectious disease which affects the upper respiratory system like nose and throat and it is easily spread.  Symptoms of common cold include cough, painful throat, running nose and sometimes fever.  Though many viruses can cause this, it is generally caused by Rhinovirus.

✧ Influenza

Influenza is commonly found during childhood.  It is caused by the virus, Myxovirus and results in inflammation of nasal mucosa and pharynx.  It is also known as flu.

✧ Mumps

It is caused by Myxovirus parotitis and it affects the upper respiratory tract.  Some of the common symptoms of mumps include fever, headaches, sore throat and swelling of parotid glands which makes the jaw movement difficult.

✧ Chicken Pox

It is common among children but adults also may get it.  Affected people will have blisters or sports in the body and face along with fever.  Those blisters with fluid will drain but sometimes they may leave scars.

✧ Measles

Measles is caused by Rubeola virus and it is easily caught by people from other infected people.  Symptoms of measles include eruption of small rashes in skin cough, sneezing, redness of eye, pneumonia and bronchitis.  There is no cure for this disease.  Yet people can recover from this by proper rest and diet.

Disease	Causative Organism	Mode of Transmission	Tissue/Organ affected	Symptoms
Common Cold	Rhino virus	Droplet infection	Upper respiratory tract (Inflammation of nasal chamber)	Fever  Cough, Running nose, Sneezing and Headache
Influenza	Myxovirus	Droplet infection	Respiratory tract (Inflammation of nasal mucosa, pharynx)	Fever, Body pain, Cough, Sore throat, Nasal discharge, Respiratory congestion
Mumps	Myxovirus parotitis	Droplet infection, Contact with infected person	Upper respiratory tract	Enlargement of parotid gland, movement of jaw becomes difficult
Chicken Pox	Varicella Zoster virus	Droplet infection Direct contact with infected person	Respiratory tract	Eruptions of the skin, Fever and Uneasiness
Measles	Rubeola virus	Droplet infection, Direct contact with infected person	Respiratory tract	Eruption of small red spots or rashes in skin, Cough, Sneezing, Redness of eye, Pneumonia, Bronchitis

  3. Prevention  

Prevention is better than cure.  Airborne diseases can be prevented if we take certain measures.

➜ Avoid close contact with people who have active symptoms of disease.

➜ Maintain personal hygiene.

➜ Keep the patient in complete isolation.

➜ Cover nose and mouth while sneezing or coughing.

➜ Avoid touching the face with unwashed hands.

➜ Wash your hands thoroughly.

➜ Timely vaccination can prevent the diseases.