Modding Help Making planets with atmosphere and airless effect

So, I am not an experienced modder and I'm just fooling around a bit right now. I miss the good old versions where the environment was an adversary, at least during the early stages of the game. Now you go fetch an EPP or another and the only danger you ever get from the environtment is accidental steps into pools of lava. So, I made an adjustment to the breathing EPP. Now it slowly uses up your oxygen supply in airless biomes. But here's where I am starting to scratch my head because I want to have this slowly depleting effect on biomes with, say radioactive (toxic) atmosphere too.

I think in older versions you had to use these two parameters in your .biome file to make it lack atmosphere: "barren" : true and under the old statusParameters (where temperature used to reside): "breathable" : false. That would make the biome lack atmosphere. Now there is only one parameter to use: "airless" : true. This removes atmosphere and sets the biome to not breathable. Is there some way, through LUA I would suspect, to make a biome retain its atmosphere (the "skybox") and at the same time make it not breathable?