Ozone, ultraviolet ray filter, can be very harmful on the earth's surface. It is known that the ozone that is generated naturally extends to the stratosphere, but the same does not occur with that produced by pollution.
Although it could not be proven so far, a group of chemicals have found the chemical mechanism used by ozone to damage plants.
Nicholas Hewitt and his colleagues at the University of Lancaster say that by reacting ozone with the plant ethene reagents are formed called "free radicals". Consequently, the flowering process slows down and decreases resistance to external agents.