ozone holes - NOT from rockets (instead, volcanoes)
Althouh there is some validity to rocket exhaust affecting ozone, the actual amount would be mininmal.
* Ozone holes are fund near the poles where cosmic radiation is less effective at creating it from O2 high in the atmosphere
* In general each ozone hole can be mostly attributed to volcanic activity in which the effluent gasses flow towards the hole
* The chemicals alleged to cause these holes are MUCH heavier than air,.and although for a short period of time the rocket will pass through the ozone layer, the amount of these chemicals that could interact with the ozone layer will be relatively small (in other words only a fraction can affect the ozone layer)
On a relate note...
Until we launch nuclear engines that have NO air pollution, our cell phones, internet, television, and other worldwide communications are going to need *ROCKETS* to get them satellites into orbit, and those rockets are going to affect things... minimally.