Grade 4 | Science | Diseases, Our Environment, Olympiad, CBSE, ICSE, SOF, ITO
Water pollution or drinking contaminated water can result in a number of diseases related to the digestive system like cholera, typhoid, dysentery and diarrhoea.
Symptoms of cholera:
Jaundice is a disease associated with yellowish or greenish pigmentation of the skin and whites of the eyes due to high bilirubin levels. It mostly occurs in children but it can happen to adults as well.
Polio (also known as poliomyelitis) is a highly contagious disease caused by a virus that attacks the nervous system. Children younger than 5 years old are more likely to contract the virus than any other group.
2 types of polio
1) Non-paralytic polio
2) Paralytic polio
loss of reflexes
loose and floppy limbs
Causes: Polio is highly contagious. Virus spread through the feces of an infected person. The major cause is the consumption of water contaminated by the waste of an infected person.
There is no cure for polio. The best way to treat polio is to prevent it with vaccinations. Polio vaccines in form of injectibles or drops should be given to children from time to time.
Heat stroke is an elevation in body temperature followed by dehydration. Heat stroke.
B) Muscle cramps
Serious heat stroke can lead to organ failure or cause damage to the brain.
To avoid heat stroke we should keep our body hydrated. We should drink lots of water and eat fruits.
We should wear light and loose fitting cotton clothes.
We should avoid going out in the direct sun in summer. We should take an umbrella if required.
If a person suffers from heat stroke following should be done as first aid :
A) Move the person immediately away from heat.
B) Cool the person by sprinkling water on his body.
C) Sponge with cool water.
D) Use ice packs or ice towels to cool down the body.
A disorder involving excessive body fat that increases the risk of health problems.
Junk food, lack of physical exercise and overeating can lead to obesity.
Major diseases caused by mosquitoes are :
Asthma is a respiratory system disease.
Tuberculosis is another respiratory system disease.
Respiratory system diseases are caused by air pollution.
Vitamin A deficiency can cause loss of vision and night blindness.
Scurvy is caused by the deficiency of vitamin C.
Symptoms: tiredness, uneasiness, lethargy, bleeding and swollen gums.
Beriberi is caused by the deficiency of vitamin B.
Symptoms: numbness in legs and hands, difficulty in standing and walking, nausea, vomiting, confusion, difficulty in speaking.
Deficiency of vitamin D can cause rickets, a disease associated with deformation of bones. Vitamin D is obtained from sunlight.
Anaemia is a decrease in haemoglobin or red blood cells in the body. Symptoms: Pale skin, body cramps, fatigue, dizziness, loss of energy, headache etc.
We should eat iron-rich fruits like green leafy vegetables to fight anaemia.
Calcium is necessary for healthy bones and teeth.