Do not eat at work
A lot of dirt? Or a lot of germs? If it is really dirty (germy) don't eat or drink at work.
Make sure you wash your hands well before you eat or drink. A teacher once said, there is a difference between clean dirt and dirty dirt. A dusty place might look bad, but if you don't have breathing trouble, it won't likely harm you. Also being around a few germs helps make your immune system stronger.