Question

How can ozone be both a pollutant and something beceficial to earth

Answer 1

Ozone is 3molecules of oxygen i.e O3

which prevent the earth from the harmful UV rays...
on the same time that O3 cna't be utilised by human as oxygen, as breaking it down will give O2 ,which is breathable

hope it helped

Answer 2

Maybe because it keeps the harmful sun rays out but keeps all the air pollution in