While the moon has basically no atmosphere, I don't think it would matter much. Plenty of lunar dust would get blown around by the force of the engines, and the mass or that dust would contribute. Beyond that, the exhaust itself has a lot of force, and is probably plenty.
https://www.youtube.com/watch?v=9HQfauGJaTs
Look at the Apollo missions taking off, it's quite violent for the surround area.