Droppings of just about every sort are bad for you in some way shape or form. While I have never seen any reports specifically on chinchilla droppings, I know for a fact that rat and mice droppings along with bat droppings and bird droppings can be dangerous and cause health issues. With birds such as pigeons the danger comes from the accumulations of droppings which pigeons use as nesting material. it's highly disgusting. clean up of that sort of mess requires the use of a face mask and the droppings should be wetted first to keep the dust down while cleaning up the accumulations. Breathing the dust from droppings is the main concern. That is why with pigeons when they nest near an air conditioner intake it can cause people inside a building to become sick. Rodent droppings are much the same. The drier the dropping the more risk of particles becoming airborne. I've had to crawl through urine and feces covered insulation in attics many times searching for rats and I've never gotten sick, even when I was unsafe and went in without a proper mask. But I'm also fairly young and in good health. Those that are going to be affected to a noticeable degree are going to be the elderly, and those already in poor health. Knowing what I do about pests (I'm a pest control technician) I still have chinchillas and do not believe that I am putting myself or my family in any danger. I'm sure that just about everyone with chins is running a vacuum daily to keep the poops picked up. With that level of cleanliness common among so many owner, I think I can safely say that the accumulation of poops is not going to happen to a level that would present danger, nor would the poops be able to dry out enough to become dangerous.