Environmental Engineering Reference
In-Depth Information
Figure 6.5
The break-down of a chlorofluorocarbon molecule (CFCl
3
) and its effect on ozone
immensely destructive to the ozone layer (see
Figure 6.5).
In 1974, two scientists working in the United
States on the photochemistry of the stratosphere,
came to the conclusion that CFCs, however inert
they may be at the earth's surface, are highly
susceptible to break down by the ultraviolet
radiation present in the upper atmosphere.
easily soluble in water. In consequence, they
remain in the environment relatively unchanged.
Over the years, they have gradually accumulated,
and diffused into the upper atmosphere. Once
they reach the upper atmosphere, however, they
encounter conditions under which they are no
longer inert—conditions which cause them to
break down and release by-products which are
