What are the risks when having been exposed to asbestos for one week?

A friend of mine, master of self-sabotage, cut off his windowsill while renovating his kitchen. There was a huge dust cloud and after research he found out that the windowsill could be made of asbestos. And he f'in stayed in his apartment for another week before he decided to temporarily leave!!! Anyone who can tell me what expects him? Asbestosis? Lung cancer? Has he been exposed long enough for long-term damage?
I'd appreciate if people who know something about that could talk to me.