1. Improper disposal of waste can cause:
a) air pollution
b) water pollution
c) sickness and diseases
d) acid rain
e) flash floods

A Air pollution
1. Air pollution occurs when there are lots of gaseous waste materials in the air.
2. The gaseous waste materials include dust and smoke that contain harmful substances.
3. Smoke is released into the environment when forest are burnt or when fuels are burnt in vehicles and factories.
4. Air pollution can be caused by the following:
a) open burning
b) Burning of fuels in factories and motor vehicles
c) Forest fires
d) Spraying of insecticides and other chemical substances

1. To avoid pollution, we must dispose of waste properly.
2. Disposal of waste from housing areas
a) Rubbish must be thrown into rubbish bins, and not burnt or thrown into drains
b) Rubbish must be wrapped properly in a plastic bag and tied before it is thrown away.
c) Rubbish is collected by garbage trucks to be sent to waste disposal centres.
3. The collected rubbish will be disposed of in two ways.
a) The rubbish is dumped in layers at a large site called a landfill. The rubbish is compressed using a steamroller.
b) The landfill site must be safe from flooding is heavy rain occurs and also far from housing areas.
c) In some places, the rubbish is burned in an incinerator.
4. A lot of rubbish like old newspapers, aluminium cans, glassware and some plastics can be recycled. Before we throw our rubbish away, we should separate it up into different groups.
5. Waste water from factories, homes, schools and offices is usually channeled into the sewage system.
6.The sewage is treated in sewage treatment plants to make it safe before it is discharged into the sea.
7. Factories should be fitted with long chimneys. Filters are fixed on the chimneys to reduce the release of air pollutants.

1. People throw away tons of rubbish every day.
2. If this great amount of waste is not disposed of properly, our land will be polluted. Our surroundings would be dirty and smelly.
3. Some of the improper ways of waste disposal are shown below.

Waste Materials

1. Waste is any material that is no longer useful.
2. In their daily activities, people dispose many types of waste, including used paper, empty packages and food leftovers.
3. Waste materials can be divided into three types.
a) Solid waste such as glass, wood, paper, plastic, metal and food leftovers.
b) Liquid waste such as oil, detergent, chemical waste and sewage.
c) Gaseous waste such as vehicle smoke, cigarette smoke, pesticides and toxic gases.
4. Waste materials come from various sources.

Bahan Buangan

1. Bahan buangan ialah sebarang benda yang tidak berguna lagi.
2. Setiap hari,manusia membuang pelbagai jenis bahan buangan termasuklah kertas, bungkusan kosong dan sisa makanan
3. Bahan buangan boleh dibahagikan kepada 3 jenis
a) Bahan buangan pepejal seperti kaca, kayu, kertas, plastik, logam dan sisa makanann.
b) Bahan buangan cecair seperti minyak, detergen, bahan buangan dan kumbahan.
c) Bahan buangan gas seperti asap kenderaan, asap rokok, racun perosak dan gas toksik.
4. Bahan buangan datangnya daripada pelbagai sumber.

1. Food preservation gives many benefits to us.
a) The food will last longer
i) With preservation processes, perishable products such as fruit and vegetables, meat and fish can be kept for a long time.
ii) Food can be marketed to far places overseas. This can increase income in the agricultural sector.

b) The food is easy to store and distribute
Canned foods are much easier to store and distribute from one place to another compared to raw foods.

c) Food wastage is reduced
i) Excess food can be kept in a refrigerator for the next meal.
ii) Without preservation, perishable foods like vegetables and fruits cannot be eaten a few days after harvesting.

2. Food preservation is very important to fulfill the food supply needs in a country.
3. It ensures that food supply can be distributed to the people at all times.
4. Furthermore, problems like food shortage or famine can be avoided.