Page 102 - Active Science 5 Ebook and Activity

Factual Study
Humans can hear the sound limits ranging from 20 to 20,000 hertz or equivalent with a range of up
to 140 decibels (noise level). More than this range, damages the eardrum and the other organs.

Land Pollution

The mixing of harmful substances on
the land is called land pollution or soil

pollution. The dumping of wastes like
glass, plastic, metals and chemical waste
from industries makes the land infertile
and causes land pollution.

Due to the excessive use of chemicals

like pesticides, fertilizers, insecticides in
agriculture, land is being polluted day-by-
day. Land

Roots of trees hold the soil together. Cutting Pollution

down of trees or deforestation is one of the
major reasons of land pollution. By cutting
down trees, soil becomes loose and can be
easily carried away by blowing wind and

rainwater that causes loss of precious soil.
This is called soil erosion which makes Soil Erosion
land barren.

Harmful Effects of Land Pollution
1. Land pollution decreases the fertility of land. Due to this, plants fail to grow on such

land.
2. Near the land where waste is dumped, there is extremely bad smell and odour.

3. Land pollution also causes many respiratory diseases, problems with skin and
serious diseases like cancer.

Factual Study
Many diseases like skin problems,
Activity 8.4
birth defects and respiratory issues are
Students will prepare a presentation on causes caused by land pollution. According to
and effects of land pollution. the report of Cornell University, about
40 percent of deaths in the world are

caused by land pollution.

102 Active Science-5