What is the aspect of language that deals with writing but nor speaking

An _ exposure is a repeated or prolonged exposure(over months or years) that may bring about slowly developing symptoms.

Waste is deposited into in thin layers which are then compacted and covered with soil.

You're in the breakroom at work when you see a coworker posting a cartoon on the bulletin board. you read it as you pass, and it's a joke about women breastfeeding in public. a male walks up, looks at it and starts laughing. other make employees walk up, and one takes it down saying he is going to make copies for everyone. what do you do?