Answer:
Reason for environmental degradation:-
Water gets polluted. One of the
reasons is the use of several
pesticides and other chemicals to
protect our crops from diseases
and pests.
These chemicals are either washed
down into the soil or into the
water bodies.
From the soil, these are absorbed
by the plants along with water and
minerals, and from the water
bodies these are taken up
by aquatic plants and animals. This
is one of the ways in which they
enter the food chain.
As these chemicals are not
degradable, these get
accumulated progressively at each
trophic level
As human beings occupy
the top level in any food chain, the
maximum concentration of these
chemicals get accumulated in our
bodies. This phenomenon is
known as biologicalmagnification.
ozone (O3) is a molecule formed by three
atoms of oxygen. While O2,which we
normally refer to as oxygen, is essential for
all aerobic forms of life. Ozone, is a deadly
poison. However, at the higher levels of the
atmosphere, ozone performs an essential
function. It shields the surface of the earth
from ultraviolet (UV) radiation from the
Sun. This radiation is highly damaging to
organisms, for example, it is known to cause
skin cancer in human beings.
The amount of ozone in the atmosphere began to drop
sharply in the 1980s. This decrease has been linked to
synthetic chemicals like chlorofluorocarbons (CFCs) which
are used as refrigerants and in fire extinguishers. In 1987,
the United Nations Environment Programme (UNEP)
succeeded in forging an agreement to freeze CFC
production at 1986 levels.