The problem isn't just whether a TSO changes his gloves. How often is the outside of that glove touched by a bare hand or the previously worn "dirty" glove or laid down on a table or stuffed in a pocket - contact with an unclean surface if you will - in the process of getting it out of the box and putting it on? Given the prior food-services experience of some TSOs, isn't there anyone who can train them on sanitation or sterile practices?