Water contaminated by human beings, chemical or industrial wastes can cause a variety of communicable diseases through ingestion or physical contact.

i) Name any two diseases caused by polluted water.

ii) Why do we drink boiled water?

iii) How can you reuse waste water in your houses?

i) When water gets contaminated, it can spread various diseases through its ingestion or physical contact. This is because the disease-causing germs (pathogens) get a medium to spread themselves. Examples of two such diseases which are transmitted through water are:

1. Cholera

2. Typhoid

ii) The practice of boiling the water kills various pathogens (disease-causing germs) that might be present in the water. Heat destructs their cell components. Most of the bacteria are killed on boiling water and viruses become inactive. Thus we should drink boiled water to prevent ourselves from water-borne diseases.

iii) Waste water is the water which is released from our kitchens, bathrooms, and toilets. This water can be reused by us in following ways:

● We can build channels so that water from our kitchens and bathrooms can flow to our gardens.

● Water used for washing clothes can later be reused to wash cars.

● Water used to wash pulses and rice in our kitchens can be collected to feed cattle.