How can I prevent myself from getting lice at work?

Yes. If you are aware of exposure, keep your hair tight, and up.
This is usually. This is usually transferred by clothing or brushes and combs. People who have it need to be treated.
Be aware of sources. Lice are a human only parasite that must feed on human blood daily.They can live for a day or so on brushes/combs/scarves/hats/coats so sharing any of these can infect you. A communal hat or coat rack is also a potential problem.Avoid these and you should be fine.