Detail this asset from Unity Asset Store: https://assetstore.unity.com/packages/vfx/particles/environment/toxic-environment-effects-15726
But now you can download Toxic Environment Effects FREE.
Toxic Environment Effects v1.1
With this pack you can create a toxic and infected environment with poison gas clouds, spore emitters and infected/toxic terrain. It is also suitable for any alien world.
– Toxic + infected particle effects
– Gas + spore emitter effects + meshes
– Tris count emitters: 126 – 266
– All particle textures are white, so their color can be easily changed in the particle system
– Toxic/infected ground textures
– Ready to use prefabs of all models are provided
unityassetcollection.com – Get all paid Unity Asset for free