The ozone layer is located in the stratosphere. This is the layer that is closest to earth after the atmosphere we know and breathe here. It’s important to note that the ozone layer is extremely close to earth. This is because its doing its best to block UV rays from getting to earth, to protect us. When UV rays hit our skin, the first signs we have had UV damage come in the form of sunburns.
Granted, tans usually mean that we have had UV exposure too, but if it comes from routine, short exposures, it isn’t as bad as other kinds of tanning. Sunbathing, without sunscreen application, can lead to more UV damage than what can be seen with just a sunburn. The ozone layer is important, and the proximity to earth only helps it do its job.