I just had a meeting with a director for an upcoming show and he wants a pit of dirt on the stage. Real dirt. Then he wants it to rain. Real water plus real dirt equal Mud. I am not looking forward to that clean up. However my concern comes from the dirt. I want to make sure that the dirt won't make actors or audience members sick. I once worked on a show with dirt and 3 actors and a technician got respitory complications. Any suggestion on what kind of dirt I should look for?