I work the local sort, I was told by my supervisor that he wants me to start sweeping out a couple of trucks free from dirt and debris every night. As if I don't have enough to worry about helping with airs parking and unloading trucks. This dirt is caked in from these rural routs to the point where I need a mask. I asked him why the lady who cleans the trucks doesn't do it, he said "it's not part of her contract." Do I have to do this?